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    0-30 Vdc Stabilized Power Supply

    You were right, it was a output transistor  has died (2n3055). But they are on a huge cooler. I replaced them now, hooked up my multimeter for amper-measurement and ... one died again. So it seems only one of them route the power, and dies. They were from the same charge, so resistance and hfe...
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    0-30 Vdc Stabilized Power Supply

    Hey guys, as my power supply is finished and actually working, i was testing very heavy loads (2x12volt halogen lamps) with it. But something is gone wrong, my voltage regulation doesnt work anymore and i get fully 40 volts on my output. Also U2 is getting very hot, so i replaced it, still same...
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    0-30V Stabilized Power Supply

    @ audioguru Ive calculated the working point on my circuit (42v plus, -1.6 volt minus) to a voltage divider of 10k ohm and 440 ohm. Already did a dirty testing with 10k and 470 ohm, its better, but still problematic. Still the d10 isnt in so far. I will do more testing with a potentiometer...
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    0-30V Stabilized Power Supply

    Ive replaced C2 and C1 with 470uF. The negative voltage goed down to -1.6V now. But the behaviour is different from just drop too fast. It does oscilate. In my case it does go up to +3V, and after some quick flashes of connected leds it goed down  again to -1.2 again and is slowly dropping. I...
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    0-30V Stabilized Power Supply

    Hey guys, sorry for putting pressure on this, but i/we do have fixing of this problem as a task on sunday ;] Can someone give me some input if he has the same problem and if it would help to reimplement q1 again and how to impelent it into the REV2 circuity? I need clean on/off behaviour on my...
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    0-30V Stabilized Power Supply

    Hi. Ive increased C3 to 47uF + 100uF. Same behaviour. Increased to 47uF + 470uF same. 47uF+2200uF is way better. But for this is took reduced the C3 for 2200uF, only a slight increase of voltage/current on OFF. Couldnt i feed C3 from C1? With 2200uF on C3: Negative Voltage of -1.5 on negative...
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    0-30V Stabilized Power Supply

    Hmm. Okay still it does happen, and i do use TI Sampled tle2141, so they should be fine. Can anyone else who build the supply test this behaviour? Redwire maybe? I dont think its something in the circuit like the multimeter? I will test further later today. Will see what happens on U3 pins...
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    0-30V Stabilized Power Supply

    Yep, i came also to the same calculations. There are heatsinks with 0.8K/W, but they are too huge and its not really possible to mount the 2n3055 on it. I will later check my local dealer, ive got an idea .... Today i was playing around a little bit with the Powersupply and burned some leds...
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    0-30V Stabilized Power Supply

    One more picture:
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    0-30V Stabilized Power Supply

    Hi audoguru, I have no idea how you could find that problem but you was right, again! I actually double/three time checked all the parts, but this one slipped through ... R12 was a 56 Ohm instead of 56K Ohm. No wonder it wasnt working. Now it does freaking work. Voltage goes up to 30+something...
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    0-30V Stabilized Power Supply

    @ audioguru, thanks for the input, you were right. It was the Q2. I put in a new one and now its working like it was before, but still not right. I can: Set voltage from zero to 11.1 Control current and also turn it off completely (led lights on) Now some data: - i used redwires pcb with latest...
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    0-30V Stabilized Power Supply

    Arghs. Crap. Mixed up Base and Emitter of 2n3055 and now somethin weird is happening, but its not working. Output of maximal 3V and extreme hot R1 and R2. But iam able (in a small range) to control voltage and current. extreme strange. Test everything will be fun :/ I think i saw some picture...
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    0-30V Stabilized Power Supply

    Iam aware of that. Also on the other side, one 18v/1.5VA transformer couldnt blow anything up, and still possible that it works ;] Yep, got that. 3mA is fine enough.  Redesigning is a little bit problematic at the moment because of the lack of overview and compelte understanding of the cirtcuit...
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    0-30V Stabilized Power Supply

    1) Still it should work or will it not? I meant this transformators just for testing so far. Is it possible to trim it down with RV2? What is the minimum voltage needed for correct working of the voltagecontrol? Putting them in series with 36v is also a little high then :/ 2) Yes, but only for...
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    0-30V Stabilized Power Supply

    Thanks alot redwire, it seems  it got it then. Here my toner-selfmade-double-side-etched-pcb. I hope you can see it on the pictures. I will test it tomorrow with the small 18v trafo. If everyone finds any wiring problems ...
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    0-30V Stabilized Power Supply

    Redwire? Could you please exlain the offboard wiring? Points 7a 7 8 3 and 1. Also what it is with D7 Diode and if d2+d3 are replacing it? Or are they needed? 4 and 4a are ground? Current outputis wired from Output Transistor?
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    0-30V Stabilized Power Supply

    just to check: this one ok as bridge? (asking because of the glass) http://diodes.com/datasheets/ds21221.pdf 25A GLASS PASSIVATED BRIDGE RECTIFIER 600V 4700 or 6800uF/63VDC  should be enough for stable voltage at low currents right?
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    0-30V Stabilized Power Supply

    Thanks for answering and thanks for the PCB. I also crosschecked it yesterday and and seems to be fine, only some values differs. Alignments its a little bit tricky but there is still some leeway. Ill finish the toner transfer to the 2nd side today and etch this one.
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    0-30V Stabilized Power Supply

    @audioguru, wolud you please approve the files i posted here: http://www.electronics-lab.com/forum/index.php?topic=19066.msg100521#msg100521 before i start to build i have to know =)
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    0-30V Stabilized Power Supply

    Exactly. Thanks. But it would only overheat if i set the current limiter HIGHER than 2.1A DC and also consume it. Fine. Cool i also can go with lower voltage then. nice. Wonderfull, exactly what i wanted to hear. Because this way i can first use a weak Trafo and after i found a strong and cheap...
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