Variable power supply 0-30V 1A using transistors

This is simple Variable power supply 0-30V 1A projects. I use the transistor 2SC1061 or H1061. It used for control current up to 1 Amp. The circuit use transistor 3 pcs only, it very small circuit. The Q3-C1061 must hole heat sink with. VR1 for control voltage 0-30V at 1A

The details
This circuit is easily designed for beginners to learn the operation of the regulated output circuit, because a majority of the circuits in now often made of the IC packages, which some of you might not like. When before we used the transistor circuit,
We readily can buy the equipments, cheap and be adapted easily substitute another number.
In addition when they are damaged you can repair with replacement the parts some pieces only, not need to replace them all with the same as the ICs.

In this circuit is designed be A series REGULATOR form that has very performance, you change the voltage output 0V to 30V by adjust the Potentiometer – VR1-10K, so it is controller a bias voltage of the transistor Q2-BC337.

The parts of circuit
R1,R2________10K 1/4W Resistors
R3,R4________100ohm 1/4W Resistors
C1_________1000µF 35V Electrolytic Capacitors
C2,C3_________100µF 35V Electrolytic Capacitors
Q1,Q2__________BC337 50V 800mA NPN Transistor
Q3__________2SC1061 or TIP41 or H1061 or MJE3055 50V 2A NPN Transistor
D1-D5__________1N4002 100V 1A Diode

Making this project
– Put the complete equipment correctly by the circuit.
– Enter the power into circuit, then uses a voltmeter measure the voltage output.
– Adjust the VR1, then notice meter should be changed as required.
– Try to connect the load to the circuit, The output voltage should be adjusted to a constant does not change.
– The Q3 should be equipped with a cooling medium size.

Regulator 0-30V 1A By Transistor (C1061)
Circuit 0-30V mini Variable power supply by C1061

PCB 0-30V mini Variable power supply by C1061


The other adjustable power supply regulator circuit, that use transistor is base of circuit please see below.

  1. DC Supply adjustable Voltage 0-20V at 1A
  2. Simple variable dc power supply 0-30V 2A for beginners


  1. mark gil March 19, 2015 Reply
  2. MR OHM 1970 April 24, 2016 Reply
  3. momename April 27, 2016 Reply
  4. cody October 1, 2016 Reply

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