Lm317 0 12v Variable Power Supply Circuit Diagram

The lm317 is a 3 terminal positive voltage regulator with a 1 25 to 37 volts output voltage range.

Lm317 0 12v variable power supply circuit diagram.

It is a charge pump circuit used to create a low power negative dc voltage source. It is actually very similar to most of the lm317 based power supply with some key difference. They provide a fixed regulated power supply. But what if need to vary the power supply voltage so here we have variable voltage regulator ic lm317.

The lm317 will supply more than 1 amp of current to push the bases of the external power transistors and with an approximate gain of ten the combo ought to provide 15 amps or even more. The lm317 constantly works using a voltage variation of 1 2 between the output and adjustment terminals and demands a minimal load of 10ma hence a 75 ohm. The picture above is the circuit diagram of the power supply. One of them is the extra pair of 470 uf capacitor and 1n4007 diodes below the main bridge rectifier.

Hence in order to control the current and voltage two. We have 78xx 7805 7806 7812 etc series voltage regulators for positive power supply and 79xx for negative power supply. The lm317 regulator terminals are. The current limiter circuit taken from lm317 s datasheet is shown in the above figure.