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    0-30V Stabilized Power Supply

    All OpAmps are the same, MC34071. You know, it doesn't bother me much that the LED is on, as long as the rest is working like a charm.  ;)
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    0-30V Stabilized Power Supply

    Problem solved. I have replaced the BD139 and added a heat sink. Now it works great. Thank you for your help and for the design. Just one more thing. My current limiting LED stays on all the time, though the current is not limited. When it goes into limiting stage, the LED lights brighter. What...
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    0-30V Stabilized Power Supply

    No way the heat sink would be too small. See the pictures attached. Also I have noticed that U2 gets hot. Any ideas, why?
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    0-30V Stabilized Power Supply

    The transformer is just fine, it's a 30$ 150VA toroidal transformer. It's good quality. Something else was the problem. I have found it. I have integrated a multimeter on the same board, I have mounted a 7824, a 7812 and a 7805 for the uC and the LCD display. It wasn't a good solution. When I...
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    0-30V Stabilized Power Supply

    Hello. I built it, it works, but it doesn't work correctly. Input voltage on C1 rises up to 57V!!! And I don't know why. Is it because R1 has 22k instead of 2.2k? The lady from the electronics shop messed up the values. Output voltage varies from 0-30V, though. Should I be worried about the...
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    0-30V Stabilized Power Supply

    It's because I already have all the parts, but the capacitor. Also in the country I live 12000uF capacitors are a bit hard to get. I could order one from Farnell, UK, but the delivery would cost me as much as the capacitor and it's not worth it. Thank you for your replies, I will try with the...
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    0-30V Stabilized Power Supply

    So I should use a 2200uF capacitor in parallel? Would that be ok?
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    0-30V Stabilized Power Supply

    audioguru, I have an other question: does C1 have to be exactly 12000uF? I've found only 10000uF. Do I have to add two more 1000uF in parallel (or one 2200uF [?]) or the circuit will work without problems only with the 10000uF capacitor?
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    0-30V Stabilized Power Supply

    What if the transformer is bigger? Like 150VA. would that be a problem?
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