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    0-30 Vdc Stabilized Power Supply

    Hi Blacque, We are talking about these, right? I think you are right, they shouldn't get that hot when they are bolted to the case... I think I'll try one of these. I just now discovered that they have also only 50ppm. That should work. Annother advantage of "my" current measuring is that...
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    0-30 Vdc Stabilized Power Supply

    Hi Blacque Jacque, Annother way to preset the current is to shorten the output with a suitable switch and measure the voltage drop across R7. This voltage gets to a 100k/27k potential divider. Now we have 0,3V @ 3Amp across the 27k resistor which can be fed to a panelmeter. A 1k pot can be...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru, Well, there a not that much AC in my neighbourhood and the line here is quite stable. But after all this power supply should be very reliable, so I'll take the 445APs. Little expensive, but so be it. I can get also more output voltage this way and probably even less ripple because...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru, Thank you for the new list. I wondered whether the OPA604 could be used instead of OPA445. This is an audio-tuned opamp with +/-24V. I did some measuring with my toroidal trafos and the unloaded voltage is 14,634% higher than the rated one. And after rectifying and filtering...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru So, when those (expensive :o) opamps are used, the only thing to change in the project would be the layout, probably more 2N3055 with each one serial resistor and a big rectifier bridge, right? Getting 5A is impossible with my transformers but I'm sure I don't need that much...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru, I think you have a point there. Using higher rated opamps would be a much better solution. Even if the tl081 won't go bang at the first time, they will fail at some time later because of getting too much voltage for a long time. Okay, so I need to have high-voltage opamps. I'm...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru, I haven't seen a schottky bridge module either, but I could build it easily with 4 single diodes. But since I have complete "normal" modules here, I think I will use them instead. They look as they could stand >10A. Very stable things which can be bolted. Adding a few more...
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    0-30 Vdc Stabilized Power Supply

    Hi audioguru, First of all thanks for your quick help. There are a few things I'm not getting. If the absolute max. rating of the opamps is exceeded by using a 20.5V transformer, hoy can you use a 24V one? Surely a 24V transformer has a even higher voltage if unloaded? And where do you get...
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    0-30 Vdc Stabilized Power Supply

    At first, hello to erveryone. I was able get 2 toroidal core transformers with 120 Watts from some old devices. So I think the power itself should be enough to build 2 power supplys. Unfortunatley, the transfomers have a secondary voltage of only 20.5 VAC. I wonder if that would be enough to...
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