Description and Circuit
Make your own lab power supply complete with adjustable voltage and constant current source.Using single IC (LM324)
Here is the circuit.
Strip Board Layout.
Part List
1 LM324 Opamp1 Ammeter 100 µA 1k ohm
1 Voltmeter
6 IN4001
1 Zener Diode 9.1V
1 Full-Wave Bridge Rectifier
1 LED
2 NPN Transistor, 2N3055
1 NPN Transistor, BC109C
1 Transformer
2 E-Capacitor 2200µF
1 Potentiometer 5k ohm linear
1 Potentiometer 10k ohm linear
1 Resistor 500 ohm
2 Resistor 2.2k ohm
1 Resistor 560 ohm
1 Resistor 6.2k ohm
2 Resistor 68k ohm
1 Resistor 0.22 ohm
4 Resistor 4.7k ohm
Component Image.
LM324 |
2N3055 |
Some Pictures.
Posts
19 comments :
Very nice. Would you be willing to create a one-off AC-to-AC wall transformer, or do you know any person or company who might?
Maybe I will come out with PDF version of instruction later. For the time being, I redraw the strip board layout to make it easy. I hope this may help.
How much voltage/current can this circuit cupply? I've been dying to make one that will cleanly supply 12v@10A.
I’m using 500VA transformer. Theoretically, on 50V max current is about 10A. Since both 2N3055 can support up to 30A (15A each), the limit depend on the transformer it self. If you have larger transformer maybe u can increase this value. But you need a bigger heat sink. I never try to test the current limit before (afraid of burning it).
answer #1
ops! I plan to use seperate diode but when I found 1 old full wave rectifier from my spare part stock I forgot about it. Sorry for that. You can see at the picture, there are no diode on it. I attach the full wave rectifier near the transformer output.
answer #2
I didn't know about the limit actually (38V) but what I know that I did measure the transformer output and the reading show me 50V. Anybody have some explaination about this?
Please follow this link for voltage control circuit detail.
I try to simulate it with 12v zener and it works. You may experiment with this. Maybe you can replace the whole section with just a simple voltage divider that can give ~95% of the transformer output voltage.
Hi Guys,
I'd like to build a 220V power supply for a 12V(100W) car amp.; can u help me ? thanks, steven
>After in depth study of lab power >supply Schematic,I suggest some >modifications.Use a taped >transformer(17+17V)to control power >Dissipation of PASS TRS 2N3055.
>Use a Voltage sensing circuit to >select 17V AC or 36V AC.Replace >BC109 with BC160 or BD135.Add 0.1 >Ohm 3W Resistors in between >2N3055,Emitter & out put. To save >LM234 use spare power supply of >24V.I think this will help.
If I use a smaller transformer (more like 24VAC), will this circuit still be usable? Or do I have to modify something (zener voltages, resistors?)
Theoretically yes. AFAIK, your max voltage might be more or less 22.7V.
Hi
I really like this design, can someone tell me how I can make it a dual power supply?
Thanks
Sorry, but I do not understand the function of the LM324 on the right hand side. Is there a connection missing in the circuit diagram?
Regards, Johann
LM324 is Quad Operational Amplifier. (4 'op-amp's in a package)
cool design Power supply couple IC LM324 and 3055, i thought, the power supply only 7812 and LM317 :-)
Hi,
Nice device.
Quez: I've got another ampere meter, not 1kohm. Can I juse it if I switch the 560ohm resistant to another one so the resistor + amperemeter = 1560 ohm ? I belive my meter is 700 ohm, so then I nees a 860 ohm resistor.
Thanx
James, what is your meter spec? full scale at 100µA? power supply max current? Maybe I can come out with a formula to help.
One more problem to be solved before it can be called "Lab Power Supply". The output capacitor of 2200 should not be that big. It will supply excessive current in the moment of load connection, and before of the current limitting. If the 100uF is not enough, then something is wrong with the overall stability.
everything i do as u told... but all become unuseful.. i have spend 3 of my day to find solution i have burn 4 lm 324 n and 2 pcb board..! please help me...
Hi, thanks,
Many days later got this kind of circuit.
Electronics Project
Post a Comment