Recent content by bongo4000

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    Convert 0-30V 3A PSU to 5A or more

    what does the most recent schematic and part list for the 5A (or more) psu look like? i myself converted the 24V/3A psu to a 24V/6A version, which seemed to work well as long as i powered it from a lab psu for first test, but then it went up in smoke when connecting a 24V/200VA transformator...
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    0-30 Vdc Stabilized Power Supply

    thanx! so where can i find the modified schematic and partlist for the redesigned psu? bongo
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    0-30 Vdc Stabilized Power Supply

    hi audioguru i'm a bit puzzled. why do you call it a low voltage transformer? there are 2x 12v in series, so i think it's the same as the original project with the 24v. so why do i have to adjust these resistors? voltages are still the same! the changes against the original project, i'm aware...
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    0-30 Vdc Stabilized Power Supply

    so what modifications do you recommend to get the whole thing working reliable? (so i can go and look for new components) thanx! bongo
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    0-30 Vdc Stabilized Power Supply

    so you think i have to use the ti OPA445AP to solve the problem?
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    0-30 Vdc Stabilized Power Supply

    yea, this is exactly why the 1n5402 is there. i think when i add a diode as in your image, i have the problem that the input of U2 can have up to 30v, while this OP is not powered, and i don't think that the U2 is very happy with this situation ;-( why do you think that the 1n5402 is not...
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    0-30 Vdc Stabilized Power Supply

    yes, the 25V have been there with the voltage control to 0V, and current control to 0A. so i connected a 1E resistor to the output, as i thought the voltage was because of a loaded cap. so i think, there was some over current for a short time, until the 1E resistor burnt away. i think this must...
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    0-30 Vdc Stabilized Power Supply

    hi audioguru thanx for the quick response. i checked the neg supply, and it seems to be fine. btw: i always had 25v on the output, since i connected the trafo, although i had the voltage pots on 0v. (before, with the current limiting lab power supply instead of the trafo, it all worked well) so...
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    0-30 Vdc Stabilized Power Supply

    for the first tests, i powered the circuit from a lab power supply with +25 v/ -5v. so it worked well. now that i connected the transformator and rectifier, the negative voltage dropped to about -1v. when i remove the OP U2, i again get the -5v. any idea what could be wrong?
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