Wideband UHF Amplifier

This UHF wideband amplifier(Ultra High Frequency amplifier) has a total gain of 10 to 15 dB in the 400 – 850 MHz domain frequency so it can be used where the tv signal is weak.

For this UHF antenna tv amplifier to work correctly you need to cut the components pins as short as possible. C1, C2, C6, C7 are SMD type ( surface mounted ). This antenna tv amplifier or uhf wideband amplifier need to be build inside of a metal box and then connected close to thetv antenna.

The power supply is a simple 12V stabilized source. The antenna tv amplifier can be connected directly to the power supply thru coaxial cable of the tv antenna but you need a 10 – 100uH coil on the alimentation line. The tv set will be connected to the uhf amplifier thru a small coupling capacitor.
Adjusting is easy, just bring the P1 to the middle and then adjust it untill you obtain the best tv image quality.

Antenna TV amplifier circuit schematic

For moretv antenna amplifierscheck the list bellow.
Tv antenna UHF amplifier components:
L1 = L2 = 2 turns, 3mm ?
L3 = L4 = 10uH or 10 turns, 0.2mm ? on ferrite
T = 2SC3358

Low Noise Non-Inverting Shock Sensor Amplifier

The shock sensor charge is converted to a voltage and amplified with a precision resistor ratio for gain accuracy. Paralleling amplifiers reduces noise.

Low Noise, Low Power Photodiode Amplifier

Low Noise, Low Power Photodiode Amplifier is Better than Monolithics. Low Bias Current, Low Current Noise and Unity Gain Stability Keep the Circuit Operational from 0ohm to several Gohm. Amplifier input noise density and gain-bandwidth product were measured to be 2.4nV/rtHz and 100MHz, respectively, with only 3.8mA supply current.

Low Noise, Low Power Photodiode Amplifier With DC Precision

Instead of simply grounding the LT6202 noninverting input, an LTC2050 drives it (and therefore the source) exactly to where it needs to be for zero JFET gate voltage. Output offset is 200mV and output noise is 2mVP-P measured in a 20MHz bandwidth.

Source: http://www.hqew.net/circuit-diagram/Low-Noise$2c-Low-Power-Photodiode-Amplifier-With-DC-Precision_7917.html

Modification of Tripath TA2024 Amplifier Tamp Super Budget

A package from the People's Republic of China dumped into the mailbox this week. In an article in the Sound and Vision as mentioned a mini amplifier with usb input that surround.no had taken, I saw in the comments that deal extreme selling the same amp. After some searching I found another amplifier based on TA2024 without usb, and then started google ball rolling with reading about Sonic T-Amp, Tripath, TA2024A, B and C. I wound a little haphazard up buying this on ebay for $ 40 incl P:


It says in the ad that it should be based on TA2024B, but in reality it turned out to be the old TA2024 (A). As if I did not know enough about Chinese quality and veracity of the industry. Well, well.

Anyway, it sounds very decent to cost the equivalent of 1 new DVD. But we can not just stop there? So this is the thread where all proposed modifications will be received with thanks! See attached photos for goodies components are carefully selected.

This like so many others seem to be based on Tripaths own circuit suggestions: Data Sheet, see page 5 and 6 A difference that I find is that 2 pieces' listening CSW stated to 180 V μF/16 they have spent 470 mF / 16 V. Is it done in an attempt to improve the power capacity in? In the data sheet recommended high quality Panasonic conditions or the like. Should these be replaced or upgraded?

At the end there are 4 pieces of fluff on 10μH and 4 pcs Co. of 0.47 mF. It says 0.22 mF should be used with 8 ohm load. Could it be something to be gained from switching output coils and capacitors? I had a little trouble finding the coils with low inductance at Elfa.

50W amplifier based LM3886TF

This 50W amplifier circuit is designed for quad power stage on computers equipped with sound cards MonsterSound Diamond MX300. With this circuit we get 200W output power with a total harmonic distortion of less than 0.01%. Somewhat classified as High-End Audio.
The audio signal from the sound card enters the operational amplifier by pin 10 (non-inverting input). A 1μF capacitor passes only the audio signal, blocking the DC component that may exist. A 10K potentiometer (optional) lets you adjust the input limit. At the output a 20K resistor performs the feedback through the inverting input while a set RL power output coupled to the speaker. This set consists of a coil of 10 to 15 turns of wire 1.5mm on a resistance of 10 ohms / 2 watt. Two electrolytic decouple the power supply and a jumper controls the mute (silence) which is activated by opening the switch. The 100μF capacitor with the 47K resistor act as input delay, avoiding noise when connecting the power.
COMPUTER AMPLIFIER POWER SUPPLY:
The power supply must provide symmetrical 70VCC (35 35) with a current of 6A.

Diodes are 100V / 8A and can be replaced by a bridge rectifier. Electrolytic capacitors are 10000μF / 50V. The transformer is 220V in his primary and secondary 50V at its midpoint and current 6A for a quad configuration.
CA3140   AT90CAN128         62256       VIPER22A       TDA7377
HEAT SINK FOR SOUNDCARD AMPLIFIER :
Here is an economical solution to the problem of cooling. Instead of putting a large aluminum heatsink on each chip, it would be better to install the heatsink used in the Pentium computer chip. Yes, they are small metal 5cm x 5cm with a fan that carries a mini screw.
In fact the size of the heatsink is not adequate, but with the fan running at maximum output power amplifier is not even heated. Although it runs for a full weekend without the temperature rise.
To turn on the fan motor just put in the main line of supply current limit (causing a voltage drop) through a 100 ohm resistor and 5 watts. Every fan should have its own resistor. We recommend hanging two fans to the positive (and mass) and two fans to the negative (and mass). This charge is equal for both phases. To turn on the fan motor just put in the main line of supply current limit (causing a voltage drop) through a 100 ohm resistor and 5 watts. Every fan should have its own resistor. We recommend hanging two fans to the positive (and mass) and two fans to the negative (and mass). This charge is equal for both phases.

10 W amplifier using TDA2003

This is a circuit diagram of amplifier circuit, these circuits have a 10W audio power amplifier using TDA2003 IC from SGS Thomson popular. The IC can easily provide 10W into 4 Ohms load at 18V DC supply voltage. IC can also be operated from 12V and that makes it applicable in a car audio system. Useful features include TDA2003 short circuit protection between all pins, thermal overload protection, low harmonic distortion, low distortion. The circuit given here is designed according to the datasheet from the manufacturer and found to be working well. The following is a schematic drawing:

L6562 Circuit      TL494CN Circuit           TDA7388 Circuit

C7 capacitor DC input work decoupling.R2 and R3 are used to adjust the gain of R1 determines amplifier.C3 and cut off the top frequency.C6 and R4, and is intended to increase the stability of high frequency. The capacitor C5 couples the output to the speakers. You can try this circuit diagram for your car audio power amplifier or to a small room.

Amplifier Circuit Diagram Produced by TDA7294

The integrated amplifier circuit  TDA7294  is a Hi-Fi, high-power DMOS integrated amplifier circuit that is launched by famous European SGS-the THOMSON company. Today I will introduce three TDA7294 amplifier block the production of integrated power amplifier circuit.

1. OCL Circuit
OCL circuit diagram shown in Figure 1, the circuit is a dual channel using two TDA7294 70W amplifier. External components, the circuit is simple, available in 8 ohm load when the supply voltage for the soil 35V 70W of continuous output power. Very suitable for the playback of the environment less than 30 square meters. Rectifier circuit shown in Figure 4, such as the speaker impedance is less than 8 ohms, the power supply voltage should be reduced accordingly.

2. BTL Circuit
BTL circuit shown in Figure 2, the rectifier circuit shown in Figure 4. Two TDA7294 bridge composed of the BTL amplifier circuit, the output power up to 150W, suitable for the place of the dance halls that require high-power, stereo, 4 TDA7294. Available on the 8-ohm load when the supply voltage for the soil 25V 150W of continuous output power. When the supply voltage of ± 35V, 16 ohm load, availability of continuous output power of 180W. With TDA7294 for BTL amplifier, the load shall not be less than 8 ohms.

3. Constant-current Amplifier
Constant-current amplifier circuit shown in Figure 3, the rectifier circuit shown in Figure 4. Of the amplifier circuit is somewhat different from the previous two structures, the feedback circuit for the current sampling voltage summation negative feedback. This circuit structure is commonly known as constant-current amplifier, the circuit analysis for detailed description is only the more prominent advantages compared with the conventional constant voltage amplifier.



①The amplifier output current and load impedance has nothing to do, even if the load short circuit, it will not cause the amplifier block overheating.
②Output power increases with the increase of the load impedance to drive the speaker load certain power reserve to ensure the bass of the original music signal strength and high-frequency resolving power.
③The role of the speaker voice coil force is only dependent on the current. Speaker driven flow control oscillation bound to be faster than the VCO, the speaker vibration system.
④Input and output impedance is easy to do matching. Constant-current amplifier circuit is actually a control input signal voltage controlled current source. Its internal feedback circuit for the current sample, the voltage sum of negative feedback, input and output impedance characteristics. High input impedance, just pre-constant voltage amplifier circuit, no loss of signal voltage to the amplifier input. The high output impedance, can reduce the internal resistance of the shunt on the signal, is conducive to the output signal current is added to the load. Figure 3, the supply voltage is selected as ± 35V, the magnification ratio of the decision by the speaker and R6.

TDA7294 Datasheet, download  here

These datas come from http://www.hqew.net/circuit-diagram/Amplifier-Circuit-Diagram-Produced-by-TDA7294-_2315.html