Increase current for IC regulator Circuit

 

Increase current for IC regulator circuit

Although the 78xx series of voltage regulators with different power outputs, you can compare the power generation by stimulating this circuitry. A power transistor is used to provide additional power to the load of the regulator, maintaining a constant voltage.
?Currents up to 650mA is flowing through the regulator, begins above this value and the power transistor to run, which provides additional power to the load. This must be a sufficient heat sink, because it is probably pretty hot.
Suppose you use a 12V regulator, 7812th Input must be a few volts higher to allow for voltage drops. Take 20 volts. Let us also assume that the load to draw 5A.
The power dissipation in the transistorVce * Ic or (20-12) * 8 = 40 Watt.
There you stay warm in the winter, but you will have a large heatsink with good thermal dissipation needs do. Do you want the output current with a negative regulator, such as increasing the 79xx series, then the circuit is similar, but a kind of power NPN transistor is used instead

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