EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: LarryN7LUF on November 25, 2017, 01:10:28 am
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In a moment of weakness I bought a GW Instek GPC-3020 power supply.
It is a Dual Tracking 2 amp with 5V Fixed DC Power Supply.
I am looking for a schematic for it.
The problem is when I turn on the current of the master side the voltage goes to 44 volts and pegs the volt meter. :bullshit:
The voltage control has no effect to the voltage.
The slave side seem to be okay as I put a load on it to test it.
Thanks for any help!
Larry N7LUF
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I have a GPC-3020 and its working fine for me (although its fan is noisy) I don't have a schematic but for what its worth, would be happy to test any voltages or current in wires I can get my current clamp around for you so you can tell what its supposed to be.
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Hi Larry,
do you have a circuit or manual please?
Karl
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The voltage control on the master side does not work at all, but when I turn up the current just a little the voltage goes to 44 volts.
I did have to replace the meter back in place.
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Hi Karl, I have no manual.
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I am looking for a schematic for it.
Good luck getting one. I've personally tried contacting GW Instek about schematics before and they stubbornly refuse to give them out. They are very protective of their designs. I wish you luck though.
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When looking for a manual it may be helpful to use their other name "Goodwill Instruments" or similar. I would also be interested in a copy if you find one. Ive looked and havent seen one. Its on my list of service manuals I would like to have.
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There is a problem because there are different versions of these almost identical looking supplies that were built over many years so you have many revisions. It is hard to guess which one you have. See if these links are of any help. If one side is working correctly the other side should be a mirror image of it. Check identical points on each side to see the differences. First check that the control pot isn't fried or the pass transistor(s) in/out aren't shorted.
http://www.ko4bb.com/manuals/65.175.237.176/Tek_PS280-283_Service_Manual_Schematics.pdf (http://www.ko4bb.com/manuals/65.175.237.176/Tek_PS280-283_Service_Manual_Schematics.pdf)
http://www10.ujaen.es/sites/default/files/users/ingele/manualfuenteGW-GPC3030D.pdf (http://www10.ujaen.es/sites/default/files/users/ingele/manualfuenteGW-GPC3030D.pdf)