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DC Power supply 0 30v 5A, Adjustable regulator

This is DC Power supply 0 30v 5A, an Adjustable regulator is special that the output to 5A current. It uses LM723 DC voltage regulator IC + 2N3055 power transistor x2 to increase current up. So do the current too much than this circuit (easy circuit)

To use transformer 5A, Transistor 2N3055 to Hold Heatsink, VR1-5K to ADJ Volt Output.

5A 0-30V variable regulator LM723 and 2N3055

Circuit Diagram of Variable Regulator 0-30V 5A using LM723 and 2N3055 x 2

Note: I am sorry that tell you. I never build this circuit. So, I cannot confirm it works. If you are looking for 0-30 variable power supply.

I recommend this circuit better. It tested.

Also, You can increase current up to 5A with adding a transistor like this.

We do not offend you, In this Power supply circuit 0-30V 5A is adapted to the work
direct follow want of all of you.

This circuit is still the principle original everything. Just only changes the current limiting circuit. by use the resistors 0.1ohm 5W two pieces for the parallel, to be able to withstand loads as wanted.

We should not forget, use the resistor size 0.1Ω 5W amounting 2 pieces to parallel each other
Then, connected to the emitter of the two 2N3055. To offset features that might be slightly different, these two transistors.


Parts you will need

IC1: LM723
Q1, Q2: 2N4037 or BD140 PNP transistor
Q3, Q4: 2N3055
BD1: Bridge 10A 400V
0.5W resistors
R1, R2, R6: 100K
R3, R7, R8: 10K
R9, R10, R11, R12, R13, R14: 0.1Ω 5W
VR1: 5K or 10K potentiometer
C1: 4,700uF 50V to 7,200uF 50V Electrolytic
C2: 470pF 50V Ceramic
C3: 100uF 50V Electrolytic
T1: Transformer 24V 5A
PCB, big heatsink, and more.

To create just operators device in a PCB form and then to make correct completed is available. Without you have adjusting customized at any the circuit.

PCB layout variable regulator 0-30V 5A
PCB layout

Components layout of 0-30V 5A regulator using LM723 2N3055
The Components layout of Regulator 0-30V 5A using LM723 2N3055

Note: This is so the old circuit.
It does not has a reference voltage for 723 and not fully overload protection. Please look at :

0-50V 3A Variable power supply

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This Post Has 35 Comments

  1. Tanks . is good

  2. hi,
    can someone please modify it for 10 and 20amps, and how can i control the lm723 voltage through PIC by pwm .

  3. This is good and works. There are a few hicks up though – Whent eh voltage is beyond 20V, the IC starts heating up – the solution would be to replace the R4 resistor with a higher value. Also, when you make the pot zero, the output voltage still shows as 0.5~0.7 V. The solution could be to use a volatge doubler – a negative one and provide a -VCC as reference.

  4. Hi all I wonder if this can be modified to circito 50V amperage is ok hugs greetings Daniel

  5. Hi,is possible modifild for this circut for 0-16V. 10amp? thank you

  6. Thanks,it works.But as Sunlkumar said, when the voltage is above 20,the IC heats up.Exactly What higher value of R4 should I use?please help

  7. I feel so amazing to explore you experience in your site…please can you show me a easy way to test a power transistor?

  8. pls am having a challenge in steping down 5A to 1A using lm317T pls its really urgent and i will be so thankful, if you can assist…..

  9. First time I turned it on it worked. But then the R4 start to burn, smell and the voltage stayed at max. I tried to replace this resistor with a 10k and a 100k. But the voltage still stays at max. Do you guys think that the IC has been burned because the first attempt with the 100ohm R4?

  10. Pingback: AraBiyaSofT | Régulateur variable 0-30V 5A par LM723, CA3140, 2N3055

  11. Is over load protection is available in this circuit

  12. R4 = 3.3 K

  13. R4=3.3K
    PCB be modified

  14. Hi, xdisc
    Thanks for your feedback.
    Your job is good.
    If your project finished.
    Please share us to appreciate them.

  15. Hello!
    The supply is 24*5=120W. But your supposed output is 30*5=150W. The law on energy is not valied here. Why is it???

  16. i want to ask
    1.what is the wattage of other resistors ( R1-R8)?
    2.which substitute can i use instead of BD140? because it is not available in market here.
    3. for 2n3055 heat sinks are required?
    thanking you in anticipation.

  17. I need more explain for these circuit like ( a calculation ,the graph ,and something like that……) . Also how it’s work . please
    I’m waiting for you ……

  18. I implemented this circuit and it worked properly. Thank you! Could I use it to get a negative voltage? How?.

  19. i need the proper serial code for the diode it is mention as (10A).please help me .

  20. please help me i was also implemented this circuit, but when i adjust pot the voltage does not change, it remains at peak (35V),please help me……..,

  21. but volatage is not varying wat can i do to vary volatage.

  22. please help me i was also implemented this circuit, but when i adjust pot the voltage does not change, it remains at peak (35V),please help as soon as possible

  23. Hi
    I can not tell exactly how to solve this symptom.
    The circuit seems to has only current adjustment.
    The voltage adjustment pin is 5.
    There should be a potentiometer connected there.
    Instead there are fixed resistors.
    If You like to experiment, deleted r2 and r3.
    Take a potentiometer 5kohm and a resistors 390ohm.
    Connect one edge of pot to pin 6
    Connect middle pin of pot to pin 5
    Connect the other edge of pot in series with the 390ohm resistor to ground.

    Good luck

  24. Hi
    I built this power supply, and it works just fine, doesn’t go down to 0 vdc, but about 0,4 vdc, that’s good enough. What I would like to know is how can I overload protect, the circuit, as I have already blew one LM 723 IC.


  25. Dear all,
    Can any one please tell me the “value or any identification number” of bridge rectifier in this circuit.

  26. Friends please help to make a 30 Volt,15 Ampere vriable dc voltage regulator power supply,can you suggest a circuit with specifications.

  27. You ѕhould takе part in a contest for оne of tһe higһest quality websites on the internet.
    I’m gooing to highly recommend tһіs web site!

  28. Hi Bernard,
    Thanks for your feedback.

  29. Pcb size

  30. How Mani size this pcb

  31. thanks..

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