25V 3A Variable Power Supply Using LM350

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Here is another interesting project of Power supply. This is a circuit of a 1.2V to 25V/3A Variable Power Supply Using LM350. This IC is an adjustable three-terminal positive voltage regulator IC. It is capable of supplying 3A current over a 1.2V to 33V output range.

This IC is packaged in standard transistor packages which are easily mounted and handled. It is widely used for adjustable power supplies. It has many built-in features like short circuit protection, thermal regulation, etc. This circuit will provide a stable voltage between 1.2V to 25V with 3A current. You can adjust the output voltage through a potentiometer.

Hardware Components

S.noComponentValueQty
1.ICLM350K1
2.Diodes1N40072
3.Capacitor4700ΩF/50V, 10µF/40V, 1µF/40V1, 1, 1
4.Resistor120Ω1
5.Potentiometer2.7KΩ1
6.DC Input30V1

Circuit Diagram

25-volt-3A-Variable-Power-Supply-Circuit

Working Explanation

The circuit shown in the figure above is easy to build and all the components are easily available online or in electronics shops. This circuit is using a voltage regulator IC which provides an adjustable output of 1.2V to 25V. The input signal of 20V DC is passed through a smoothing capacitor to cancel out any unwanted noises then the filtered DC signal is fed into the voltage regulator IC. This IC has three pins. Pin 1 is an Adjust pin that is used for the function of voltage adjustments therefore we have connected a potentiometer of 2.7KΩ with it.

The desired output voltage can be adjusted through this potentiometer. Pin 2 is the input pin where the DC signal is being fed into. The output is generated from Pin 3 which is an output pin. The output is passed through another smoothing capacitor to cancel out the remaining noise and provide a clear output. This is an ideal power supply where you want regulated voltage with high current.