Help with my power supply problems please...urgent!...

[jong143]

power supply using lm312

https://www.electronics-lab.com/projects/power/009/
i folled the scehmatic of that power supply then when i put a load to the output it draws an overvoltage to the load...
anybody could give me diagram on what must be the good design for a power supply that can supply a fixed voltage of 12 volts and 20 Amperes output...
help me please and urgent..........

 

[laktronics]

Hi,
Check your connections, the power supply should work OK. Are you getting proper voltage at low currents? Disconnect the transistor collector(s) and check if LM312 gives 12V output, at less than 1 AMP. Then connect the Trans. collectors and see, it is mostly a wiring mistake.

Regards,
Laktronics

 

[jong143]

Posted: 27 Apr 2008 10:00 Post subject: Re: Help with my power supply problems please...urgent!...

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Hi,
Check your connections, the power supply should work OK. Are you getting proper voltage at low currents? Disconnect the transistor collector(s) and check if LM312 gives 12V output, at less than 1 AMP. Then connect the Trans. collectors and see, it is mostly a wiring mistake.

Regards,
Laktronics

yes im getting proper output voltage of 12 volts...when i putting a load to its output,it draws an overvoltage..from 12 volts(w/o load) to 20 volts (w/ load) whats seems to be the problem of this... please help me...

 

[WalkingBeijing]

It's likely that 1 TIP2955 is broken down when being in large current operation.

 

[jong143]

ill have to test the transistors and all of them is no defect..maybe my IC regulator have a problem...thanks for your help!!!