Adjustable Power Supply

Build Current and Voltage Adjustable Power Supply

In building the power supply that has the ability to regulate current and voltage out is very important. This feature is necessary in order to help prevent damage to the circuit. This is why the need for an adjustable power supply.

In the adjustable power supply circuit selects the various current ranges using a rotary switch. Because using a potentiometer is not practical to lower resistance/high current ranges. But you can try replacing it with a potentiometer.

At the lower current range is practical when using a potentiometer, so the lowest range of switches can be a pot with a small series resistor. Allowing for adjustment from say “10 mA to 500 mA.” Than use fixed resistors on the higher current ranges.

Adjustable Power Supply Circuit and PCB

This adjustable power supply circuit will give you a very simple, but a quite versatile voltage and current regulated supply. And down to “Zero Volts” out is a Nice Feature. The Output is reasonably short circuit protected if suitable heat sinks are used and this power supply should go down to Zero or very near Zero Volts.

Output Voltage and current depend somewhat on the transformer used, as well as which regulator used. You have a choice of an LM317 regulator circuit for 1.5 amps Max, or an LM350 to give about three amps Max.

Lets you for “plus and minus” supply voltage is recommended to make both, if necessary. This power supply can also be paralleled or placed in series for higher currents or higher voltages, As is sometimes Needed. For further information visit Adjustable Power Supply.

You may be interested in reading my other guides on How to Do a Power Supply Test and How to Make a Bench Power Supply