Tuesday, July 31, 2012

How to build 5 Watt Class-A Audio Amplifier Circuit

Description

This solid-state push-pull single-ended Class A circuit is capable of providing a sound comparable to those valve amplifiers, delivering more output power (6.9W measured across a 8 Ohm loudspeaker cabinet load), less THD, higher input sensitivity and better linearity. Voltage and current required for this circuit are 24V and 700mA respectively, compared to 250V HT rail and 1A @ 6.3V filament heating for valve-operated amplifiers. The only penalty for the transistor operated circuit is the necessity of using a rather large Heatsink for Q2 and Q3 (compared to the maximum power delivered).In any case, the amount of heat generated by this circuit can be comparable to that of a one-valve amplifier. An optional bass-boost facility can be added, by means of R5 and C5.

Circuit diagram:

Circuit diagram

Parts:

  • P1 = 47K
  • R1 = 100K
  • R2 = 12K
  • R3 = 47K
  • R4 = 8.2K
  • R5 = 1.5K
  • R6 = 2.7K
  • R7 = 100R
  • R8 = 100R
  • R9 = 560R-1/2W
  • R10 = 1R-1/2W
  • Q1 = BC560
  • Q2 = BD439
  • Q3 = BD439
  • C1 = 10uF-63V
  • C2 = 10uF-63V
  • C3 = 47uF-25V
  • C4 = 100uF-35V
  • C5 = 150nF-63V
  • C6 = 220uF-25V
  • C7 = 220uF-25V
  • C8 = 1000uF-25V
  • SPKR = 5W-8R Speaker

Notes:

  1. If necessary, R2 can be adjusted to obtain 13V across C8 positive lead and negative ground.
  2. Total current drawing of the circuit, best measured by inserting the probes of an Avo-meter across the positive output of the power supply and the positive rail input of the amplifier, must be 700mA. Adjust R8 to obtain this value if necessary.
  3. Q2 and Q3 must be mounted on a finned Heatsink of 120x50x25mm. Minimum dimensions.
  4. Add R5 and C5 if the bass-boost facility is required.

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How to build Audio Note Conquest Power amp with 300B

Circuit diagram

Circuit diagram

Part List

  • R1=200Kohms
  • R2=64Kohms
  • R3=320Kohms
  • R4=1Kohms
  • R5-6=19.5Kohms
  • R7=220Kohms
  • R8-9-14-15=150ohms
  • R10-11-12-13=1.5Kohms
  • C1-2=100uF 63V
  • C3=330nF 630V MKT
  • C4-5-6-7=220uF 63V
  • U1=6SN7
  • U2-3=300B
  • MT1=Audio transf. 1K2 /0-4-8ohms 50W

Circuit diagram

Circuit diagram

Part List

  • R1=47ohms 5W
  • R2-3-4-5-7-8=220Kohms 1W
  • R6=1Kohms 5W
  • C1-2-5-6=68uF 450V
  • C3-4=470uF 350V
  • C7-11=4700uF 25V
  • C8-9-12-13=100nF 100V MKT
  • C10-14=470uF 16V
  • D1-2=1N4002
  • BR1-2=Rect. Bringe 100V/4A
  • IC1-2=L78S05CV
  • U4=5U4G
  • T1=See Fig.2
  • T2=5H 150mA



How to build Headphone amplifier Class A

Description

Even if simple the circuit, plirej' all condition, regarding the distortion and the response of frequency. The resistance of entry is 250K and the load that can drive is between 100R and 2K. The circuit use negative coupling. His exit functions in Class A, having as active charge the BC308 and resistance 39R. The bias current is roughly 14 mA and total 15mA. The gain of unit is 25. The power supply, can be from 6V up to 24V DC. The frequency response with load 200R, it is 37ΗΖ - 470KΗZ (-1dΒ), the output voltage is 1.5V (11mW), the distortion 0.5%.

Circuit diagram

Circuit diagram



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Monday, July 30, 2012

4N26 Emitting Diode Pinout Diagram and Schematic

4N26 devices is an emitting diode optically coupled to a monolithic silicon phototransistor detector, it may be applied4n26 datasheet and pinout diagramin applications such general purpose switching circuits, I/O interfacing, and solid state relays. The following picture shown the 4N26 Emitting Diode Pinout Diagram.
And here is4N26 PINOUT Description:
1 – LED Anode
2 – LED Cathode
3 – N.C
4 – Emitter
5 – Collector
6 – Base

External Shutdown Function Circuit to the LP2954 LDO Regulator

The LP2954 doesn’t have an electronic shutdown built in, the circuit diagram bellow performshow to add external shutdown function to this5V LDO regulator which provides 5V output at load currents up to 250mA.
power shutdown circuit for LDO regulator
This is alow-power shutdown circuitwhich can be added by using a P-FET in the input lead as an On/Off switch. The switch threshold is between 1V and 3V to be a "logic level" type of the FET. If the load current is < 300 mA, there are FET devices available which have very low power losses at these currents.

(source: http://www.hqew.net/circuit-diagram/External-Shutdown-Function-Circuit-to-the-LP2954-LDO-Regulator_5622.html)

Mini2440 Reset System Circuit Diagram using MAX811

The herein schematic shows Mini2440 Reset System Circuit Diagram using MAX811. MAX811 used to monitor power supplies in microprocessor (uP) and digital systems since it provides a debounced manual reset input. The following Mini2440 use a microprocessor supervisory circuit MAX811 to reset its CPU.
max811 datasheet and mini2440 reset circuit
You may download the MAX811 datasheet here.

Sunday, July 29, 2012

How to build 30 Watt Audio Power Amplifier Schematic

Description

This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section employs only three transistors and a handful of resistors and capacitors in a shunt feedback configuration but can deliver more than 18W into 8 Ohm with 0.08% THD @ 1KHz at the onset of clipping (0.04% @ 1W - 1KHz and 0.02% @ 1W - 10KHz) and up to 30W into a 4 Ohm load.
To obtain such a performance and to ensure overall stability of this very simple circuitry, a suitable regulated dc power supply is mandatory. This is not a snag because it also helps in keeping noise and hum of the preamp to very low levels and guarantees a predictable output power into different load impedance. Finally, as the amplifier requires only a single rail supply, a very good dc voltage regulator capable of supplying more than 2 Amps @ 40V can be implemented with a few parts also.

Circuit diagram:

Circuit diagram

Power Amplifier Parts:

  • R1 = 2K2 1/4W Resistor
  • R2 = 27K 1/4W Resistor
  • R3 = 2K2 1/2W Trimmers Cermet
  • R4 = 2K2 1/2W Trimmers Cermet
  • R5 = 100R 1/4W Resistor
  • R6 = 1K 1/4W Resistor
  • R7 = 330R 1/4W Resistors
  • R8 = 330R 1/4W Resistors
  • C1 = 22μF 25V Electrolytic Capacitor
  • C2 = 47pF 63V Polystyrene or Ceramic Capacitor
  • C3 = 100μF 50V Electrolytic Capacitors
  • C4 = 100μF 50V Electrolytic Capacitors
  • C5 = 2200μF 50V Electrolytic Capacitor
  • Q1 = BC550C 45V 100mA Low noise High gain NPN Transistor
  • Q2 = IRF530 100V 14A N-Channel Hexfet Transistor (or MTP12N10)
  • Q3 = IRF9530 100V 12A P-Channel Hexfet Transistor (or MTP12P10)

Setting up the Power Amplifier:

  1. The setup of this amplifier must be done carefully and with no haste:
  2. Connect the Power Supply Unit (previously tested separately) to the Power Amplifier but not the Preamp: the input of the Power Amplifier must be left open.
  3. Rotate the cursor of R4 fully towards Q1 Collector.
  4. Set the cursor of R3 to about the middle of its travel.
  5. Connect a suitable loudspeaker or a 8 Ohm 20W resistor to the amplifier output.
  6. Connect a Multimeter, set to measure about 50V fsd, across the positive end of C5 and the negative ground.
  7. Switch on the supply and rotate R3 very slowly in order to read about 23V on the Multimeter display.
  8. Switch off the supply, disconnect the Multimeter and reconnect it, set to measure at least 1Amp fsd, in series to the positive supply (the possible use of a second Multimeter in this place will be very welcomed).
  9. Switch on the supply and rotate R4 very slowly until a reading of about 120mA is displayed.
  10. Check again the voltage at the positive end of C5 and readjust R3 if necessary.
  11. If R3 was readjusted, R4 will surely require some readjustment.
  12. Wait about 15 minutes, watch if the current is varying and readjust if necessary.
  13. Please note that R3 and R4 are very sensitive: very small movements will cause rather high voltage or current variations, so be careful.
  14. Those lucky enough to reach an oscilloscope and a 1KHz sine wave generator, can drive the amplifier to the maximum output power and adjust R3 in order to obtain a symmetrical clipping of the sine wave displayed.

Preamplifier Section:

The Preamp sensitivity and overload margin were designed to cope with most modern music program sources like CD players, Tape recorders, iPods, Computer audio outputs, Tuners etc. The source selecting switches and input connectors are not shown and their number and arrangement are left to the constructor's choice. To obtain a very high input overload margin, the volume control was placed at the preamp input.
After a unity gain, impedance converter stage (Q1) a negative-feedback Baxandall-type Bass and Treble tone control stage was added. As this stage must provide some gain (about 5.6 times) a very low noise, "bootstrapped" two-transistors circuitry with FET-input was implemented. This stage features also excellent THD figures up to 4V RMS output and a low output impedance, necessary to drive properly the Mini-MosFet Power Amplifier, but can also be used for other purposes.

Circuit diagram:

Circuit diagram

Preamplifier Parts:

  • P1 = 50K - Log. Potentiometer
  • P2 = 100K - Linear Potentiometers
  • P3 = 100K - Linear Potentiometers
  • (twin concentric-spindle dual gang for stereo)
  • R1 = 220K - 1/4W Resistor
  • R2 = 100K - 1/4W Resistor
  • R3 = 2K7 - 1/4W Resistor
  • R4 = 8K2 - 1/4W Resistors
  • R5 = 8K2 - 1/4W Resistors
  • R6 = 4K7 - 1/4W Resistor
  • R7 = 2K2 - 1/4W Resistors
  • R8 = 2K2 - 1/4W Resistors
  • R9 = 2M2 - 1/4W Resistor
  • R10 = 47K - 1/4W Resistor
  • R11 = 47K - 1/4W Resistor
  • R12 = 33K - 1/4W Resistor
  • R13 = 2K2 - 1/4W Resistors
  • R14 = 470R - 1/4W Resistor
  • R15 = 10K - 1/4W Resistor
  • R16 = 3K3 - 1/4W Resistor (See Notes)
  • C1 = 470nF - 63V Polyester Capacitors
  • C2 = 470nF - 63V Polyester Capacitors
  • C3 = 47nF - 63V Polyester Capacitors
  • C4 = 47nF - 63V Polyester Capacitors
  • C5 = 6n8 - 63V Polyester Capacitors
  • C6 = 6n8 - 63V Polyester Capacitors
  • C7 = 10μF - 63V Electrolytic Capacitor
  • C8 = 22μF - 25V Electrolytic Capacitors
  • C9 = 470nF - 63V Polyester Capacitors
  • C10 = 22μF - 25V Electrolytic Capacitors
  • C11 = 470μF - 25V Electrolytic Capacitor (See Notes)
  • Q1 = BC550C - 45V 100mA Low noise High gain NPN Transistors
  • Q2 = 2N3819 - General-purpose N-Channel FET
  • Q3 = BC550C - 45V 100mA Low noise High gain NPN Transistors

Power Supply Section:

A very good and powerful Regulated Power Supply section was implemented by simply adding a PNP power transistor to the excellent LM317T adjustable regulator chip. In this way this circuit was able to deliver much more than the power required to drive two Mini-MosFet amplifiers to full output (at least 2Amp @ 40V into 4 Ohm load) without any appreciable effort.

Circuit diagram:

Circuit diagram

Power Supply Parts:

  • R1 = 3R9 - 2W Resistor
  • R2 = 22R - 1/4W Resistor
  • R3 = 6K8 - 1/4W Resistor
  • R4 = 220R - 1/4W Resistor
  • R5 = 4K7 - 1/2W Resistor
  • C1 = 4700μF - 50V Electrolytic Capacitor
  • C2 = 100nF - 63V Polyester Capacitors
  • C3 = 10μF - 63V Electrolytic Capacitor
  • C4 = 220μF - 50V Electrolytic Capacitor
  • C5 = 100nF - 63V Polyester Capacitors
  • D1 = Diode bridge - 100V 4A
  • D2 = 1N4002 - 200V 1A Diode
  • D3 = LED - Any type and color
  • SW2 = SPST - Mains switch
  • IC1 = LM317T - 3-Terminal Adjustable Regulator
  • PL1 = Male Mains plug with cord
  • Q1 = TIP42A - 60V 6A PNP Transistor
  • T1 = 230V Primary, 35-36V (Center-tapped) Secondary,
  • 50-75VA Mains transformer (See Notes)

Notes:

  1. Q2 and Q3 in the Power Amplifier must be mounted each on a finned heatsink of at least 80x40x25mm.
  2. Q1 and IC1 in the Regulated Power Supply must be mounted on a finned heatsink of at least 45x40x17mm.
  3. A power Transformer having a secondary winding rated at 35 - 36V and 50VA (i.e. about 1.4Amp) is required if you intend to use Loudspeaker cabinets of 8 Ohm nominal impedance. To drive 4 Ohm loads at high power levels, a 70 - 75VA Transformer (2Amp at least) will be a better choice. These transformers are usually center tapped: the central lead will be obviously left open.
  4. For the stereo version of this project, R16 and C11 in the Preamp will be in common to both channels: therefore, only one item each is necessary. In this case, R16 must be a 1K5 1/2W resistor. The value of C11 will remain unchanged.

Technical data:

  • Output power: 18 Watt RMS into 8 Ohm (1KHz sine wave) - 30 Watt RMS into 4 Ohm
  • Input sensitivity of the complete Amplifier: 160mV RMS for full output
  • Power Amplifier Input sensitivity: 900mV RMS for full output
  • Power Amplifier Frequency response @ 1W RMS: flat from 40Hz to 20KHz, -0.7dB @ 30Hz, -1.7dB @ 20Hz
  • Power Amplifier Total harmonic distortion @ 1KHz: 100mW 0.04% 1W 0.04% 10W 0.06% 18W 0.08%
  • Power Amplifier Total harmonic distortion @10KHz: 100mW 0.02% 1W 0.02% 10W 0.05% 18W 0.12% Unconditionally stable on capacitive loads
  • Preamp Maximum output voltage: 4V RMS
  • Preamp Frequency response: flat from 20Hz to 20KHz
  • Preamp Total harmonic distortion @ 1KHz: 1V RMS 0.007% 3V RMS 0.035%
  • Preamp Total harmonic distortion @10KHz: 1V RMS 0.007% 3V RMS 0.02%
  • Bass control frequency range referred to 1KHz: ±20dB @ 40Hz
  • Treble control frequency range referred to 1KHz: 18dB/-20dB @ 20KHz

How to build DC-Coupled Audio Amplifier

Description

Designs for audio amplifiers with DC coupling to the load are not often encountered these days, even though they offer definite advantages. One advantage is that there is no need for the complication of a second (symmetric) power supply; another is good frequency and phase response. Also, no special electrolytic capacitors are needed for voltage stabilisation, and switch-on ‘thump’ is much reduced. To try to rescue this class of circuit from obscurity the author has designed a headphone amplifier working along the lines illustrated in Figure 1.

Circuit diagram:

Circuit diagram
It consists of a voltage divider, a voltage follower and the loudspeaker in the headphones, whose other side is connected to the junction of two electrolytic capacitors, providing the virtual earth. The potential at this point is, of course, half the supply voltage. All we need to do now is suitably couple in the audio signal to be amplified. Figure 2 shows a practical realisation of this idea in the form of a stereo headphone amplifier. The amplifier itself consists of IC1 and P1, R3 and R4 (giving a gain of 11).

Circuit diagram:

Circuit diagram
This part of the circuit demands no further explanation, and the same goes for the voltage divider mentioned above, formed by R1a and R1b. The signal is coupled in via the potentiometers. C2 and R2 have a special purpose: C2 connects the bottom end of the potentiometers (ground for the input signal) to the virtual earth. However, this capacitor creates a feedback path which can lead to oscillation of the amplifier under some circumstances. R2 damps this tendency to oscillate.
It is possible to calculate suitable values for these components, but it is better to determine them by experiment. C2 must be sufficiently large that stray electric fields do not cause unacceptable hum at the output. R2 must be sufficiently large that the voltage at the amplifier’s virtual earth stabilises quickly enough after switch-on. The polarity of the electrolytic is unimportant as no significant voltage appears across the network. It is possible to try the circuit out with the C2/R2 network shorted and observe the behaviour of the circuit at switch-on using an oscilloscope. Depending on the degree of asymmetry in the circuit, the voltage at the virtual earth point can take a considerable time to stabilise.







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How to build 18W 18W Stereo Hi-Fi Audio Amplifier (TDA2030)

Description

2 x 18W Hi-Fi Stereo Power Amplifier based around two TDA2030 ICs. It has good input sensitivity, low distortion, good operating stability and full protection against overloads and output short-circuits. It can be used as a booster amplifier for existing small systems or to drive a second pair of speakers besides the ones already connected to the system. The board needs a symmetrical power supply of ±18Vdc/3A and can be connected to loads of 8 or 4 Ohm. Large heat sink is required for this circuit. Diagram shown below indicates only left channel. Make two circuits for for stereo version.

Circuit Diagram:

Picture of the project

Parts:

  • R1 = 22K
  • R2 = 680R
  • R3 = 22K
  • R4 = 1R-1w
  • D1 = 1N4001
  • D2 = 1N4001
  • C1 = 1uf-25V
  • C2 = 22uF-25V
  • C3 = 100nF-63V
  • C4 = 100nF-63V
  • C5 = 100uF-25V
  • C6 = 100uF-25V
  • C7 = 220nF-63V
  • IC = TDA2030

If it does not work:

  1. Check your work for possible dry joints, bridges across adjacent tracks or soldering flux residues that usually cause problems.
  2. Check again all the external connections to and from the circuit to see if there is a mistake there.
  3. See that there are no components missing or inserted in the wrong places.
  4. Make sure that all the polarized components have been soldered the right way round.
  5. Make sure the supply has the correct voltage and is connected the right way round to your circuit.
  6. Check your project for faulty or damaged components.

Technical Specifications:

  • Supply voltage = ±18Vdc/3A symmetrical (see text)
  • Current consumption = 3A maximum
  • Input impedance = 500K Ohms
  • Input sensitivity = 250 mV
  • Signal to noise ratio = 80 dB
  • Frequency response = 20 - 20,000 Hz ± 1 dB
  • Distortion = 0.5 % maximum
  • Load impedance = 4 - 8 ohm







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Thursday, July 26, 2012

How to build Low Voltage Step-Down Converter

Description

Sometimes you have a situation where you have a 5-V supply voltage but part of the circuit needs a lower supply voltage. A voltage regulator from the Texas Instruments TPS62000 family [1] is a good choice for this if the current consumption is less than 600 mA.

The essential advantages are:

  1. small (but still manually solderable) SMD package;
  2. high operating frequency (750 kHz) => small external inductor;
  3. integrated power MOSFETs => high efficiency (up to 95 %);
  4. no external switching diode necessary.

Circuit diagram:

Circuit diagram
You can thus use this device to build a very compact, highly efficient voltage converter. A sample layout generated by the author is available as a file on the Elektor website. The TSOP62000 provides an internal reference potential of 0.45 V, which can be used to set the output voltage in the range of 0.5 V to 5 V by means of resistors R2 and R3. The formula for this is: Vout = 0.45 V (0.45 V) × (R2 / R3) For relatively low voltages, the value of inductor L1 should be 10 μH, but a value of 22 μH is better if the output voltage is 3.3 V or more. The input voltage can be anywhere in the range of 2 V to 5.5 V, and of course it has to be higher than the desired output voltage. The output voltage is 3.3 V with the indicated component values and an input voltage of 5 V. If you want to reduce the component count even further, you can use a member of the family with a fixed output voltage. The available voltages are 0.9, 1.0, 1.2, 1.5, 1.8, 1.9, 2.5, and 3.3 V. With this approach you can omit R2, R3 and C3, so the output can be connected directly to pin 5.







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How to build Cheap 12V to 220V Inverter

Description

Even though today’s electrical appliances are increasingly often self-powered, especially the portable ones you carry around when camping or holidaying in summer, you do still sometimes need a source of 230 V AC - and while we’re about it, why not at a frequency close to that of the mains? As long as the power required from such a source remains relatively low - here we’ve chosen 30 VA - it’s very easy to build an inverter with simple, cheap components that many electronics hobbyists may even already have.
Though it is possible to build a more powerful circuit, the complexity caused by the very heavy currents to be handled on the low-voltage side leads to circuits that would be out of place in this summer issue. Let’s not forget, for example, that just to get a meager 1 amp at 230 VAC, the battery primary side would have to handle more than 20 ADC!. The circuit diagram of our project is easy to follow. A classic 555 timer chip, identified as IC1, is configured as an astable multivibrator at a frequency close to 100 Hz, which can be adjusted accurately by means of potentiometer P1.

Circuit diagram:

Circuit diagram
As the mark/space ratio (duty factor) of the 555 output is a long way from being 1:1 (50%), it is used to drive a D-type flip-flop produced using a CMOS type 4013 IC. This produces perfect complementary square-wave signals (i.e. in antiphase) on its Q and Q outputs suitable for driving the output power transistors. As the output current available from the CMOS 4013 is very small, Darlington power transistors are used to arrive at the necessary output current. We have chosen MJ3001s from the now defunct Motorola (only as a semi-conductor manufacturer, of course!) which are cheap and readily available, but any equivalent power Darlington could be used.
SP5168    AP2161FMG-7   PCA-121P2W   956-120-5000   19458     PIC16C558-20/SS   
These drive a 230 V to 2 × 9 V center-tapped transformer used ‘backwards’ to produce the 230 V output. The presence of the 230 VAC voltage is indicated by a neon light, while a VDR (voltage dependent resistor) type S10K250 or S07K250 clips off the spikes and surges that may appear at the transistor switching points. The output signal this circuit produces is approximately a square wave; only approximately, since it is somewhat distorted by passing through the transformer. Fortunately, it is suitable for the majority of electrical devices it is capable of supplying, whether they be light bulbs, small motors, or power supplies for electronic devices.

PCB layout:

PCB layout

COMPONENTS LIST

  • R1 = 18k?
  • R2 = 3k3
  • R3 = 1k
  • R4,R5 = 1k?5
  • R6 = VDR S10K250 (or S07K250)
  • P1 = 100 k potentiometer
  • C1 = 330nF
  • C2 = 1000 μF 25V
  • T1,T2 = MJ3001
  • IC1 = 555
  • IC2 = 4013
  • LA1 = neon light 230 V
  • F1 = fuse, 5A
  • TR1 = mains transformer, 2x9V 40VA (see text)
  • 4 solder pins
Note that, even though the circuit is intended and designed for powering by a car battery, i.e. from 12 V, the transformer is specified with a 9 V primary. But at full power you need to allow for a voltage drop of around 3 V between the collector and emitter of the power transistors. This relatively high saturation voltage is in fact a ‘shortcoming’ common to all devices in Darlington configuration, which actually consists of two transistors in one case. We’re suggesting a PCB design to make it easy to construct this project; as the component overlay shows, the PCB only carries the low-power, low-voltage components.
The Darlington transistors should be fitted onto a finned anodized aluminum heat-sink using the standard insulating accessories of mica washers and shouldered washers, as their collectors are connected to the metal cans and would otherwise be short-circuited. An output power of 30 VA implies a current consumption of the order of 3 A from the 12 V battery at the ‘primary side’. So the wires connecting the collectors of the MJ3001s [1] T1 and T2 to the transformer primary, the emitters of T1 and T2 to the battery negative terminal, and the battery positive terminal to the transformer primary will need to have a minimum cross-sectional area of 2 mm2 so as to minimize voltage drop.
The transformer can be any 230 V to 2 × 9 V type, with an E/I iron core or toroidal, rated at around 40 VA. Properly constructed on the board shown here, the circuit should work at once, the only adjustment being to set the output to a frequency of 50 Hz with P1. You should keep in minds that the frequency stability of the 555 is fairly poor by today’s standards, so you shouldn’t rely on it to drive your radio-alarm correctly – but is such a device very useful or indeed desirable to have on holiday anyway? Watch out too for the fact that the output voltage of this inverter is just as dangerous as the mains from your domestic power sockets.
So you need to apply just the same safety rules! Also, the project should be enclosed in a sturdy ABS or diecast so no parts can be touched while in operation. The circuit should not be too difficult to adapt to other mains voltages or frequencies, for example 110 V, 115 V or 127 V, 60 Hz. The AC voltage requires a transformer with a different primary voltage (which here becomes the secondary), and the frequency, some adjusting of P1 and possibly minor changes to the values of timing components R1 and C1 on the 555.







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How to build 8 Watt Audio Power Amplifier Schematic

Description

Here is the schematic for an 8 watt audio power amplifier. This amp can be used as a simple booster, the heart of a more complicated amplifier or used as a guitar amp. It is very small and portable unit and can be powered through 12V battery. I built the circuit on a Vero Board and had to add extra inductors, capacitors and resistors to prevent oscillation.

Circuit diagram:

Circuit diagram

Parts:

  • R1 = 47K
  • R2 = 2.2R/1W
  • R3 = 220R/1W
  • R4 = 2.2R/1W
  • C1 = 100nF-63V
  • C2 = 10uF-25V
  • C3 = 470uF-25V
  • C4 = 2000uF-25V
  • C5 = 100nF-63V
  • IC1 = LM383
  • SPKR = 4ohm/8W

Notes:

  1. IC1 must be installed on a heat sink.
  2. C1 is for filtering and to prevent oscillation and should not be omitted.
  3. The circuit can be built on a Vero Board, universal solder board or PC board, the PC board is preferred.
  4. The circuit draws about 880Ma at 12 V.
  5. By swapping the values of R2 and R3; you can turn this amplifier into a guitar amp with no preamp required.
  6. If you can't find 2000uF, then replace C4 with a 2200uF unit.
  7. If you add a 0.2uF capacitor in series with a 1 ohm resistor to the output you can prevent oscillation of the circuit under certain conditions.

Wednesday, July 25, 2012

How to build Power Supply 50V 3A stabilized and regulated

Description

Many times we needed a stabilized, together regulated power supply and high relatively output voltage. These specifications him it cover our circuit. It 's a circuit that can give in his exit 40V until 60V 3A, with simultaneous stabilization. The materials that use is very simple and will not exist difficulties in the manufacture, is enough you are careful certain points. 1 ] For output voltages smaller of 50V until 40V, the Q1 is hot enough, so that it needs one big heatsink. 2]For output voltages bigger of 50V up to 70V, the stabilization is not satisfactory. Conclusion: ideal output voltage is 45V until 60V. In the circuit pontesometer RV1, is used in order to we change the output voltage between 40V until 70V, we can however and perhaps it should, him we replace with two constant resistors, when finishe the regulation, in the desirable price. The reason is, that with time is presented change of output voltage, up to 3V, with connected pontesometer. ATTENTION!!! The positive exit correspond in point [ A ] and the exit of 0V in point [ B ], which should not be connected in the ground.
ZY100    HMNR1288D-85I    5960-09    12L2828    VJ1206A272FXBMT    SP54HC82   

Circuit diagram

Circuit diagram

Part list

  • R1=10Kohm
  • R2=1 ohm 5W
  • R3=3.9 ohms 1W
  • R4=6.8Kohm 1W
  • R5=390 ohms 1W
  • R6=100Kohm 0.5W
  • R7=1.2Kohm 1W
  • R8=1.8Kohm 0.5W
  • R9=3.3Kohm 0.5W
  • RV1=470 ohms pot.
  • C1-2-4=4700uF 100V
  • C3-5=100nF 250V MKT
  • Q1=2N3055 on heatsink
  • Q2=BD162 or BD243 or BD543
  • Q3=BC303 or BC461
  • D1....4=Bridge 15A
  • D5=LED RED 5mm
  • D6-7=10V 1W Zener
  • D8-9-10=1N4007
  • T1=230Vac / 55V 3A







Reprinted Url Of This Article:
http://www.hqew.net/circuit-diagram/How-to-build-Power-Supply--50V-3A-stabilized-and-regulated_5546.html

How to build LM317T Voltage Regulator with Pass Transistor

Description

The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with the emitter of the pass transistor. In the figure below, the pass transistor will start conducting when the LM317 current reaches about 1 amp, due to the voltage drop across the 0.7 ohm resistor. MC68HC11K3CFN4    2965-0.5RG    CEE93    AP1301V-SPL    ADS8327IRSAT    39-53-3109    Current limiting occurs at about 2 amps for the LM317 which will drop about 1.4 volts across the 0.7 ohm resistor and produce a 700 millivolt drop across the 0.3 ohm emitter resistor. Thus the total current is limited to about 2 (.7/.3) = 4.3 amps. The input voltage will need to be about 5.5 volts greater than the output at full load and heat dissipation at full load would be about 23 watts, so a fairly large heat sink may be needed for both the regulator and pass transistor. The filter capacitor size can be approximated from C=IT/E where I is the current, T is the half cycle time (8.33 mS at 60 Hertz), and E is the fall in voltage that will occur during one half cycle. To keep the ripple voltage below 1 volt at 4.3 amps, a 36,000 uF or greater filter capacitor is needed. The power transformer should be large enough so that the peak input voltage to the regulator remains 5.5 volts above the output at full load, or 17.5 volts for a 12 volt output. This allows for a 3 volt drop across the regulator, plus a 1.5 volt drop across the series resistor (0.7 ohm), and 1 volt of ripple produced by the filter capacitor. A larger filter capacitor will reduce the input requirements, but not much.

Circuit diagram

Circuit diagram




Reprinted Url Of This Article:
http://www.hqew.net/circuit-diagram/How-to-build-LM317T-Voltage-Regulator-with-Pass-Transistor_5552.html

How to build Stabilized Regulated Power Supply Circuit

Description

This circuit of power supply, is very simple and easy to built, it can be assembled on a general-purpose PCB, finding its materials is very easy and cost-small. The output voltage is stabilized and is regulated in the region from 0V until 15V dc, with biggest provided current 1 A. The regulation becomes with the P1. The Q1 is classic power transistor and it needs to be placed on a cool rib (Heatsink), when it works continuously in the region of biggest current it gets hot. The type of transformer is standard in the market.

Circuit diagram:

Circuit diagram

Parts:

  • P1 = 330R-Potentiometer
  • R1 = 560R-2W
  • C1 = 2200uF-35V
  • C2 = 100uF-35V
  • C3 = 10uF-25V
  • C4 = 220uF-25V
  • C5 = 100nF-63V
  • D1 = 18V-1.5W Zener
  • Q1 = 2N3055 NPN Transistor
  • T1 = 220VAC – 18V@ 1.5A
  • BR1 = 4x1N4007 Diode Bridge
  • SW1 = Mains On-Off Switch


Reprinted Url Of This Article:
http://www.hqew.net/circuit-diagram/How-to-build-Stabilized-Regulated-Power-Supply-Circuit_5542.html

Tuesday, July 24, 2012

How to Perform DS3904 Digital DIP Switch Resistor into High-Impedance Mode Circuit

The advantages of using a digital DIP switch instead of a conventional mechanical one is that the digital offers small sizeDS3904 digital dip switch circuit diagramand better security. The DS3904 is one example that contain three digitally controlled nonvolatile (NV) variable resistors. It has the capability to set the variable resistors into high-impedance state.
High impedance mode of DS3904 can be achieved by written the MSB of the selected resistor register to a ’1′. It is used to generate the High value when combined with a pullup resistor (as seen in the circuit diagram). To generate Low value, the resistor register must be set in position 0 to attain the smallest resistance available from the variable resistors (typically 400W).

By connecting a pullup resistor from each of the H terminal pins to a voltage potential, a HIGH state will be created when the corresponding variable resistor is placed in high-impedance mode (source: hqew.net)

Drive Two-Six White LEDs (WLEDs) in Parallel Circuit Diagram

The parallel arrangement of LED backlights allows the control IC to utilize inexpensive low voltage CMOS processes as shown by the followingcircuit diagram which requires two to six white LEDs (WLEDs) in parallel. In many applications, LED backlights have been used in small and medium size portable LCD displays.
parallel led circuit diagram
The AAT3169 IC is capable of driving six LEDs for a total of 180mA from a 2.7V to 5.5V input. It drives the LEDs with a constant current programmed by a low-side current sink (high side current source also are available). But it can result in unacceptable channel-to-channel mismatch in large format LCD displays where a greater number of LEDs are required across a larger viewing area.

source: http://www.hqew.net/circuit-diagram/Drive-Two$2dSix-White-LEDs-%28WLEDs%29-in-Parallel-Circuit-Diagram_5522.html

Basic Circuit Modification of Kodak Disposable Camera

The following document coversthe basic of modifying Kodak disposable camera circuitto function as a high voltage currentkodak disposable camera circuit diagramlimited supply. It described the simplest modification of the circuit to be functioned as an inverter that converts 1.5V to 330 VDC or higher, accordingly.
The circuit diagram shows the original Kodax MAX Flash Unit including the semiconductors that built the circuit. The shown circuit diagram is the unmodified one which is for the regular Kodak and the Kodak Max that should be very similar if not identical. See materials and tools needed, how to disassembly and then rebuilt the modification one to be a completed project.

Get and download Basic Circuit Modification of Kodak Disposable Camera in pdf filetype (source: http://www.hqew.net/circuit-diagram/)

Monday, July 23, 2012

9-Pin RS232 Line Booster Signal Flow Direction Schematic


Herein is the scematic picture of 9-Pin RS232 Line Booster Signal Direction from an example of 232LB9R model (B&B electronics). This device is a 9-pin RS-232 repeater that re-transmits all 8 signals and carries the ground line through.
RS232 Signal Flow Direction Schematic Diagram
The schematic shows the direction of flow on each line. The DB9 female connector end is pinned out as DCE and connects directly to a standard COM port on a computer or DTE interface. The DB9 Male connector is pinned out as DTE and connects to any DCE device (modem or another9-Pin RS232 Line Booster).
 Lengthening 9 Pin RS232 Line Booster Cable Runs
For long cable runs, it might need two or more line boosters for proper operation of the RS232 interface, as shown in the above schematic. It should be installed no more than 50 feet from any RS232 transceiver.

LM4562 Noise Measurement Circuit Diagram

The LM4562 is a high speed op amp with excellent phase margin and stability. It commonly used in applications for superior audio signal fidelity. And here is the diagram of LM4562 noise measurement circuit.
LM4562 Noise Measurement Circuit Diagram
According to the LM4562 datasheet, when capacitive loads greater than 100pF, it must be isolated from the output. It can be made by putting a resistor in series with the output since it also prevent excess power dissipation if the output is accidentally shorted.

Source: http://www.hqew.net/circuit-diagram/LM4562-Noise-Measurement-Circuit-Diagram_5504.html

Freescale MC33810 Datasheet, IC for Auto Engine Control

Herein article is aMC33810 datasheetfromFreescale Semiconductor, an eight channel output driver IC which is designed for automotive engine control applications. And the following picture shows the simplified application diagram of the MC33810.
MC33810 Datasheet and Circuit Diagram
The IC built of four integrated low side drivers which are suitable for driving fuel injectors, solenoids, lamps, relays, etc and four low side gate pre-drivers which function as ignition IGBT gate pre-drivers or general purpose MOSFET.

Find detailed MC33810 datasheet, an IC for Automotive Engine Control Applications here in pdf filetype, 2.01Mb/35 pages (source: hqew.net).

Sunday, July 22, 2012

LMD18200 Functional Block Diagram and Datasheet

LMD18200 3A H-Bridge device are used to be applied on applications such as DC and stepper motor drives, computer printers, factory automation robots, servomechanisms and etc. The following figure shows the functional diagram of the LM18200.
LMD18200 Functional Diagram for motion control
According to the datasheet, this device is designed for motion control applications, it accommodates peak output currents up to 6A. In addition of 3A continuous output, LM18200 features : operates at supply voltages up to 55V, internal charge pump with external bootstrap capability, and thermal warning flag output at 145 C with shorted load protection.

See more informations about 3A H-Bridge designed for motion control application device in this LMD18200 datasheet (source: hqew.net).

Medical ECG Monitors using the AD620 Instrumentation Amplifier

One of features of the AD620 instrumentation amplifier is low current noise, this benefit allows its use in theMedical ECG Monitor Circuit DiagramElectrocardiography (ECG) monitors. A medical ECG Monitor Circuit is shown in the following picture, please click to enlarge the picture.
The picture tells the use of AD620 in ECG monitors where high source resistances of 1 MOhm or higher are not uncommon. It can improve the dynamic range for better performance when low bias current and low current noise coupled with the low voltage noise of the AD620.

Capacitor C1 maintains the stability of right leg drive loop. An isolation addition to this circuit may protect the patient from possible danger. You may see the datasheet here (source: http://www.hqew.net/circuit-diagram/Medical-ECG-Monitors-using-the-AD620-Instrumentation-Amplifier_5488.html).

Sequential Timer Circuit Diagram using NE555 Precision Timer IC

A sequential timer circuit device are used in many applications for initializing conditions during start-up or for activation of test signals in sequences such in test equipment device. The circuit diagram below shows a sequencer circuit with possible applications in many sistems.

Sequential Timer Circuit Diagram using NE555

As you can see, it uses the NE555 precision timer IC which capable of producing accurate time delays or oscillation. These timing circuits can be connected to provide such sequential control with various combinations of astable or monostable circuit connections. You can used it with or without modulation for extremely flexible waveform control.

You may see the NE555 Datasheet here (source: http://www.hqew.net/circuit-diagram/Sequential-Timer-Circuit-Diagram-using-NE555-Precision-Timer-IC_5492.html)

 

LMD18200 Functional Block Diagram and Datasheet

p>LMD18200 3A H-Bridge device are used to be applied on applications such as DC and stepper motor drives, computer printers, factory automation robots, servomechanisms and etc. The following figure shows the functional diagram of the LM18200.

LMD18200 Functional Diagram for motion control

According to the datasheet, this device is designed for motion control applications, it accommodates peak output currents up to 6A. In addition of 3A continuous output, LM18200 features : operates at supply voltages up to 55V, internal charge pump with external bootstrap capability, and thermal warning flag output at 145 C with shorted load protection.

See more informations about 3A H-Bridge designed for motion control application device in this LMD18200 datasheet (source: hqew.net).

 

 

Thursday, July 19, 2012

Spark Firing Circuitry Using a Transformer

The figure below presents an example how a transformer is used to generate the 40kV that fires your car spark plugs.
Spark Firing Circuit Diagram
The transformer which is “coil” in the above circuit diagram, used to generate the spark voltage with a very high secondary-to-primary turns ratio.
Source: http://www.hqew.net/circuit-diagram/Spark-Firing-Circuitry-Using-a-Transformer_5483.html

3-Output Isolated Flyback Regulator Circuit Diagram using LM2577

The following figure shown an example of a three-output flyback regulator built using LM2577 that has electrical isolation between the input and output voltages. The values shown in the circuit diagram will be 5V for the voltage.


THREE OUTPUT ISOLATED FLYBACK REGULATOR CIRCUIT DIAGRAM



SN65LBC175    ICM7242C/D    A070GRB04T13    HDSP-A153-00Z00    KA236-2.5    ULR1-R0005FT2   
An electrical isolation is required between the input and output terminals of the power supply for such medical instruments which require it to assure the safety of patients. In theFlyback Regulator circuit, the output may be greater than, less than, or equal to the input voltage (source: http://www.hqew.net/circuit-diagram/3$2dOutput-Isolated-Flyback-Regulator-Circuit-Diagram-using-LM2577_5486.html)

Sequential Timer Circuit Diagram using NE555 Precision Timer IC

A sequential timer circuit device are used in many applications for initializing conditions during start-up or for activation of test signals in sequences such in test equipment device. The circuit diagram below shows a sequencer circuit with possible applications in many sistems.
Sequential Timer Circuit Diagram using NE555
As you can see, it uses the NE555 precision timer IC which capable of producing accurate time delays or oscillation. These timing circuits can be connected to provide such sequential control with various combinations of astable or monostable circuit connections. You can used it with or without modulation for extremely flexible waveform control.

You may see the NE555 Datasheet here (source: hqew.net)

A6S-8102   AME8815BECS330    TRJA154K035R600...   ADG604YRUZ    SMC2-499RFI   Am29DL800BT90EE...   SY10EL32VZCTR   CLS4D28NP-330NB   TDA1517P   MC74HC595ADTR2G   HLMP-EH25-TV400   DA103J12B215QF6

Wednesday, July 18, 2012

Microchip TC4422 High Speed MOSFET Drivers Datasheet

This isTC4421/TC4422 datasheet, a high current buffers/drivers device has ability in driving MOSFETs which is producedTC4421 TC4422 Switching Time Test CircuitsbyMicrochip.TC4422 used to be applied in applications such as pulse generators, motor and solenoid driver, driving the largest MOSFETs, and line drivers for extra heavily-loaded lines.
TC4422 features 9A high peak output current, wide input supply voltage operating range (4.5V to 18V), 2A max continuous output current, typically 30 ns propagation delays, low supply current and output impedance, and pin-compatible with the TC4420/TC4429 6A MOSFET driver.
TOD3202AE     VI-2TLEY    TVS06RF-21-41SA...    WDS2-70B    P6SMB39AC    AD7312Q    
In the datasheet you will found table with pin function and descriptions, Supply Input (Vdd), Control Input, CMOS Push-Pull Output, Ground, Exposed Metal Pad, and Application Informations. The picture shown Switching Time Test Circuits of the TC4421/TC4422 which pinout is for the DFN, PDIP and SOIC packages.

Complete Microchip High Speed MOSFET Drivers can be read in the TC4422 datasheet (source: http://www.hqew.net/circuit-diagram/Microchip-TC4422-High-Speed-MOSFET-Drivers-Datasheet_5467.html)

Semiconductor Article: All You Need to Know About Power MOSFET

Here we provide you with asemiconductor articleregarding the power MOSFET (metal Oxide Semiconductor FieldThe MOSFET Vertical Structure Showing the Parasitic BJT and DiodeEffect Transistor). This device used in a wide range applications such as SMPS, computer peripherals, automotive, and motor control. You will find a general description aboutpower MOSFETsinside the article.
What will be described by the article are sections such as History of Power MOSFETs, types of field effect transistors, The Structure of a MOSFET (lateral and vertical channel design),The Characteristics of a MOSFET(advantages, disadvantages, and basic characteristics), Characteristics of MOSFET’s in ON and OFF States, and user’s manual.

All You Need to Know About Power MOSFET can be seen completely in this semiconductor article (source: hqew.net).

HD4074818TF    B66397-G200   XRT86L30   U.FL-2LP-066J1-...   IRGI4065PBF     LM99CIMM

Pulse Width Modulated Push-Pull Converter Circuit Diagram using TL494

The following circuit diagrams Pulse Width Modulated (PWM) Push-Pull Converter using TL494 switchmode power supply control.
Pulse Width Modulated Push Pull Converter Circuit Diagram
According to the TL494 datasheet, it can generate 14mV 0.28% for its line regulation test, 3.0mV 0.06% for load regulation, 65mV Output Ripple, 1.6A short circuit current test, and 71% for its efficiency test.

Tuesday, July 17, 2012

LM741 Single Op Amp Internal Block Diagram and Datasheet

Below is the internal block diagram ofLM741 single operational amplifier(Op Amp),also we provide you with the datasheet of LM741 from theFairchild Semiconductors.
CMDZ5249B IS62WV5128BLL-5... V23993-EVA1029-... HPWT-MD02 M29W040B120N1T

Fairchild LM741 Internal Block Diagram (Pinout Diagram)
LM741 operational amplifieris especially designed for a wide range of analog applications since it provides superior performance in integrator, summing amplifier, and general feedback applications.

And here is the LM741 op amp datasheet.
Source: http://www.hqew.net/circuit-diagram/LM741-Single-Op-Amp-Internal-Block-Diagram-and-Datasheet_5411.html

300V-10mA (High Voltage) Output Booster Circuit Diagram

The circuit provided belowdiagrams a high voltage boosterand has 10 mA output current. It is called as a positive-output-only circuit that will drive 350V into a 30k load and is almost immune to load shorts and reverse voltages.
300V High Voltage Output Booster Circuit Diagram
Though it shown a 350V limit, thisoutput booster circuitcan be extended the output capacity into several kilovolts. The parallel diodes at the summing junction prevent high voltage from destroying the amplifier during circuit start-up and slew rate limiting.

LB1410 VI-JNNCM EDV42-120-32-15... LP3985IBLX-2.9 M38227M8MHP

See more explanation about 300V-10mA (High Voltage) Output Booster Circuit Diagram in detailed in this Op Amp Booster application notes (source: hqew.net). See another Amplifier/Conditioner article you may interest in this blog.

Piezoelectric Transformers Design Article and Schematic

If you need to look for a suitabletransformer designfor non-lead materials, a nonlead Piezoelectric Transformers, youthe Radial Transversal mode transformer schematic diagrammay consider the folowing article that contain various transformer structures description. Piezoelectric transformers are now widely used in applications such as backlight inverters, AC-DC converters, car navigation system, LCDs for small screen devices and etc.
AD7576SQ M29F010B45N3F BQ24123RHLTG4 HAUTS0V10E6PRA1... VI-JNNIM
In the depth of the article there are informations about the piezoelectric transformer advantages, examples of transformer designs (Radial Transversal mode transformer, Longitudinal-Transversal mode transformer, Ring type transformer, and Unipoled transformer) including the schematic diagram of those transformers type.


At the end of article there are calculations regarding the gain (matching load), efficiency, and mode of each piezoelectric transformer under the low power condition. The article was written by Shashank Priya and colleagues from International Center for Actuators and Transducers Pennsylvania State University, University Park. Please read complete article aboutPiezoelectric Transformers Design Article and Schematicin this 117 Kb pdf filetype –http://www.hqew.net/circuit-diagram/Piezoelectric-Transformers-Design-Article-and-Schematic_5439.html


Monday, July 16, 2012

Construct Square Wave Oscillator using CMOS Logic Element

The following information within contain application note which describe you with severalsquare wave oscillatorsthatan oscillator made from a single Schmitt (Schmitt Trigger Oscillator)can be built using CMOS logic elements. You will be described with the advantages of the oscillation circuits and the description of RC oscillators and two crystal controlled oscillators.
There are detailed sections discuss such logicaloscillators, stable RC oscillator (three gate oscillator), a single schmitt trigger makes an oscillator, and a crystal oscillator that uses only one CMOS inverter as the active element. Also there are illustration diagram for Odd Number of Inverters to oscillate, Propagation Delay, Waveforms for Oscillator, sample of a popular oscillator, and Waveforms for Schmitt.

See more about Construct Square Wave Oscillator using CMOS Logic Element in this Oscilator article of pdf filetype (source:hqew.net )

EXB28V472JX   PM0603-R10J-RC   D38999/20FC4SN   CG2145L   IRLS640A   CXD1804CR   TPS2111PWG4   LD3986J122R-E   TK61042STL   BQ2085DBTR   HDSP-3601-KI000   X113-SERIES   CL101J7AS205HQA

New RGB Backlighting System for Liquid Crystal Display

We provide you with an article contain information about new backlighting system forLiquid Crystal Displays (LCDs)Schematic diagram of RGB backlight using feedback controller system descriptionutilize RGB LED lightsources, an optical sensor and feedback controller. The aim of using optical feedback is a color stability over temperature, maintaining constant brightness, and controlling any color point or brightness required by the LCDs.


DGS9-03AS    K4H510438B-TC/L...   CA3108E14S-6SBA...   FX5545G0083V5T1   TEH100M10R0FE   JR21BRB-10PC   P11S1A0BGSY0010...   B43501A3567M
  • MTLB258-Y   EC2-3SNU   DB3   FCA-325-WV9   AS7C31025A-12TJ...   A32100DXV-2PQ20... Within the article you will find section discuss about Main functional blocks of the backlighting systems, The understanding of xy coordinate and brightness y (colorimetry), Luxeon RGB lightsource, Typical LED performance in temperature/lifetime behaviour, LED output wavelength using pulse width modulation (PWM), the RGB backlighting system description (click figure to enlarge), Feedback controller (clipping, brightness, calibration), Photodiode sensor for averaging radiometric power, and Luxeon LED driver descriptions.

    See the capability of high performanceLED backlight systemfor LCDsusing optical feedback and luxeon lightsources for color controlling in the following LCD article (source:http://www.hqew.net/circuit-diagram/New-RGB-Backlighting-System-for-Liquid-Crystal-Display_5408.html ).
  • The LT1109 Step-Up DC/DC Converter Datasheet and Circuit Diagram

    If you need to construct a simple DC/DC Converterwhich can deliver 5V at 100mA from 3V input or 12 V at 60 mA from aLT1109 Step Up DC DC Converter typical application5V input, you may consider the LT1109 IC series fromLinear Technology.It is available in 8-pin version features a logic controlled shutdown pin that turns off the oscillator when taken low.
    Thecircuit diagramperforms the typical application of this device. According to datasheet, another feature of LT1109 are uses Off-the-Shelf Inductors, require only 33uH inductor, 120 KHz Oscillator, only three external components needed to design a completeDC/DC converter device, and 1.6V minimum start-up voltage. Therefore, this IC can be applied in battery powered equipment, 3-5V Converter or 5V-12V Converters, Flash memory VPP generators, peripherals, disk drives and etc.

    Please see more about The LT1109 Step-Up DC/DC Converter in LT1109 Datasheet, and see circuit diagrams such bootstrapping circuit operation, 3V to 5V Converter with Shutdown, and 3-Pin Package Flash Memory VPP Generator



    ATV2500BQ-25PC    CPOPC5CEP   NTE263   JANTXV1N4614D-1   AD7492ARZ-REEL   TEA2037A   IDT70824S45PF   HDSP-0883-FA300   SN65LVDM051D   CD74AC573MG4   H8S/2643F-ZTAT   TMP86PM29F   PI6C2308-1HLI   PSD814F2-20U   REG101NA-2.8/2K...

    Sunday, July 15, 2012

    How to build Self-Powered Fast Battery Tester Schematic

    Description

    This circuit runs a fast battery test without the need of power supply or expensive moving-coil voltmeters. It features two ranges: when SW1 is set as shown in the circuit diagram, the device can test 3V to 15V batteries. When SW1 is switched to the other position, only 1.5V cells can be tested.

    Circuit diagram:

    Circuit diagram

    Parts:

    • R1 = 2.2K
    • R2 = 3.3R
    • R3 = 10R
    • R4 = 4.7K
    • R5 = 33K
    • R6 = 100K
    • R7 = 100K
    • R8 = 220K
    • R9 = 330K
    • R10 = 500K
    • C1 = 10nf-63V
    • C2 = 10nf-63V
    • C3 = 100nF-63V
    • C4 = 100nF-63V
    • C5 = 100nF-63V
    • C6 = 100nF-63V
    • C7 = 100nF-63V
    • C8 = 220uF-35V
    • Q1 = 2N3819 FET
    • Q2 = BC337 NPN
    • Q3 = BC337 NPN
    • D1 = 5mm Red LED
    • D2 = 1N4148
    • D3 = 1N4148
    • D4 = 1N4148
    • D5 = 1N4148
    • D6 = 1N4148
    • D7 = 5mm Red LED
    • IC1 = 7555
    • IC2 = 7555
    • SW1 = DPDT Switch
    • BUT = Battery Under Test
    • P1 = SPST Pushbutton

    Testing 3V to 15V batteries:

    1. Switch SW1 as shown in the circuit diagram.
    2. Place the battery under test in a suitable holder or clip it to the circuit.
    3. Wait some seconds in order to let C8 reach its full charge.
    4. LED D1 illuminates at a constant intensity, independent of battery voltage.
    5. If D1 illuminates very weakly or is completely off the battery is unusable.
    6. If D1 has a good illumination, press P1 and keep an eye to LED D7. If D7 remains completely off, the battery is in a very good state.
    7. If D7 illuminates brightly for a few seconds, the battery is weak. This condition is confirmed by a noticeable weakening in D1 brightness.
    8. If D7 illuminates weakly for a few seconds but D1 maintain the same light intensity, the battery is still good but is not new.

    Testing 1.5V batteries:

    1. Switch SW1 in the position opposite to that shown in the circuit diagram.
    2. Place the battery under test in a suitable holder or clip it to the circuit.
    3. Wait some seconds in order to let C8 reach its full charge.
    4. LED D1 illuminates very weakly only in presence of a new battery, otherwise is off.
    5. Press P1 and keep an eye to LED D7. If D7 remains fully off the battery can be in very good state.
    6. If D7 illuminates brightly for a few seconds, the battery is weak.
    7. If D7 illuminates weakly for a few seconds, the battery is still good but is not new.
    8. If you are suspecting a 1.5V cell to be completely discharged, a better test can be made wiring two 1.5V batteries in series, then running the 3V test.

    Circuit Operation:

    FET Q1 provides a constant current generator biasing LED D1 and Q2 Base. In this manner D1 illuminates at a constant intensity, independent of battery voltage from 3 to 15V and Q2 (when P1 is closed) applies a constant current load of about 120mA to the battery. IC1 is a square wave generator oscillating at about 3KHz. IC2 acts as an inverter and drives, together with IC1 but in anti-phase, Diodes D2-D6 and Capacitors C4-C7, obtaining a voltage multiplication.
    C8 is charged by this raised voltage and R8-R10 form a voltage divider biasing the Base of Q3. When P1 is open, a very light load is applied to the battery under test and Q3 Base is biased in order to maintain LED D7 in the off state. Closing P1, a 120mA load is applied to the battery under test. If the battery is not fully charged, its output voltage starts reducing: when this voltage fall 0.6V below the battery nominal voltage, Q3 Emitter becomes more negative than the Base, the transistor is hard biased and D7 illuminates.
    Obviously, this state of affairs will last a few seconds: the time spent by C8 to reduce its initial voltage to the new one, proportional to the voltage of the loaded battery. If the battery under test is in a good charging state, its output voltage will not fall under a 120mA loading current, so LED D7 will stay off. When testing 1.5V batteries, the circuit formed by Q1, Q2, D1, and R1 & R2 does not work well at this supply voltage, so a 150mA load current is applied to the BUT by means of the 10 Ohm resistor R3 after switching SW1A. Q3 bias is also changed via SW1B.

    Notes:

    1. To set-up this circuit applies a 6 to 7.5V voltage source to the input and trim R10 until LED D7 is completely off (without pushing on P1).
    2. 1.5V test position needs no set-up.
    3. CMos 555 ICs must be used for IC1 & IC2 because they are the only cheap devices able to oscillate at 1.5V supply or less.

    FSUSB30MUX   HDSP-5508-GJ000   AO30F48-L   MAX427CSA   AFL2809DX/ES   S71GL032A08BAI0...





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    How to build Car Battery 6V or 12V charger

    Description

    Always we needed a charger with which we can charge the car battery. This circuit can charge automatically, fast and rightly, batteries 6V and 12V. A basic factor in the success in the circuit operation is the use of transformer [T1] of good quality with very good insulation and resistance in the short circuits. The Q1 via divider R1-2, the TR1 and the R4, functions as regulated current source. The current via the R9 drives the power transistors Q5 -6, where is strengthened X2000 times roughly. In a car battery charger the voltage is roughly 6V until 8V. With these conditions the charge current is roughly 1.2A [is regulated by TR1]. When the battery charge slowly, is increased her voltage in across. In the 7V it begins conduct the D1. As long as it?s increased the battery voltage is decreased the voltage in across the R3 making Q1 conductible. This continued as far the current reaches the 6A roughly. Then via the fall of tendency in utmost the R10, becomes driver the Q4. The current that in excess in base of Q5 grounded, confecting the current charge constant. When the battery charger [14.4V] is completely, activated the parallel to the battery circuit that is constituted by the R6, D8, and D2 until D6. Simultaneously turns on the D8 that shows that battery charged completely. Simultaneously Q2 turn on from cause of voltage fall in the R6. The Q3 becomes conductible and grounding some of current in the Q5 base. When the voltage across the battery reaches roughly in the 15V the current in the Q5 base is very small, so that stops the battery charging. Diodes D5-6 protect the circuit from error placement of battery or from short-circuit of big duration. Diode D4 protects the circuit from error placement of poles of battery. Then Led D9 turns on shows the connection ERROR. Closing switch S2 short the diode D2 [6.8V], now we can charge a battery 6V.
    AME8817AEDZ475Z
         TSA5059ATS     UBC1A471MNS     SN74CBT3125CDRE...     WB202     HB04373     M27C2001-10XF1T...     RC0603FR-0756R2...     VBD15-D48-D15     SSA-EB1PL2-12EA...     EP2S-4N2     CS3106A20-27SY-...

    Adjustment

    The inceptive charge current should be adjusted via the TR1 in 1.2A. Adjust can become with a battery 6V. Connect in cascade with the battery a ampere meter [biggest 10A]. If does not exist battery 6V, sorted output charger via their ampere meter and we adjust with the TR1 the current in 1.2A. At the regulation switch S2 it should they are in the 12V place, that is to say open. Attention should be given in the diodes D2 and D3 precision because these protect the battery from overcharge. If the voltage deviation is up to 100mV we believe to consider as acceptable. If you meet difficulties in the current adjustment and TR1 is not enough, you can change the resistance R4 value, until you measure charge current become 1.2A. The two parallel resistors that constitute the R10, it should they are placed in distance by printed board and Q5-6, because they are heated. Bridge B1 and Q5-6 should be placed on heatsink after isolate electric from this with suitable silicone mica. Bridge B1 and the PCB where it will be placed circuit should connected with near and fat cables, special there that the current are big. Also the lines in PCB should have proportional width [in the drawing they appear with far line]. The manufacture should become in a good metal box, suitable dimensions so that exists good ventilation. The all manufacture requires the proportional experience. The WORK WITH BATTERIES REQUIRES VERY BIG ATTENTION IN the HANDLING, BECAUSE EXIST ALWAYS the DANGER of EXPLOSION.

    Circuit diagram

    Circuit diagram

    Part List

    • R1-11=1K ohm 0.5W 5%
    • R2=22K ohm 0.5W 5%
    • R3-5-8=10K ohm 0.5W 5%
    • R4=2.2K ohm 0.5W 5%
    • R6=100 ohm 0.5W 5%
    • R7=100K ohm 0.5W 5%
    • R9=470 ohm 0.5W 5%
    • R10=0.08 ohm 10W [2X0.18 ohm parallel] 5W
    • B1=Bridge Rectifier 25A/40V
    • D1-2=6.8V 0.4W Zener
    • D3=4.7V 0.4W Zener
    • D4-6-7=1N4148
    • D5=18V 0.4W Zener
    • D8=LED 5mm Yellow
    • D9=LED 5mm Red
    • Q1-2=BC557
    • Q3-4=BC547
    • Q5=BD139 [On Heatsink]
    • Q6=2N3055 [On Heatsink]
    • TR1=4.7K Trimmer Pot.
    • C1=4700uF 40V
    • C2=1uF 25V
    • T1=230Vac//15V 10A Transf. [See Text]
    • F1=Fuse 1A Slo Blo [5X20mm]
    • S1=2X2 Switch 10A per contact
    • S2=1X2 step mini switch
    • J1...4=Flat Pin Connector
    • J5=6pin Connector 2.54mm pin step
    • A=0-10A Ampere meter
    • Batt=12V or 6V Battery


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