We have 78xx 7805 7806 7812 etc series voltage regulators for positive power supply and 79xx for negative power supply.
Lm317 0 12v variable power supply circuit diagram.
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.
This is a simple circuit which can be used to limit the current in our circuit based on the resistance value r1 the formulae to calculate the output current is iout 1 2 r1 based on these formulae the value of pot rv1 is selected as 100r.
It is actually very similar to most of the lm317 based power supply with some key difference.
But what if need to vary the power supply voltage so here we have variable voltage regulator ic lm317.
The current limiter circuit taken from lm317 s datasheet is shown in the above figure.
The lm317 regulator terminals are.
The lm317 is a 3 terminal positive voltage regulator with a 1 25 to 37 volts output voltage range.
Lm317 variable voltage regulator circuit lm117 lm217 lm317 variable voltage regulator characteristics.
In input out output adj adjust.
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.
They provide a fixed regulated power supply.