SSSSSmokey
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- Jun 11, 2004
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For anyone who has built the TEPS power supply, have you ever had this problem? I am totally finished except for one small problem: instead of outputing 24v like I planned, it outputs 50v. Adjusting the VSET (the trim pot) adjusts it from about 49.7 to 50.3. I have tried everything, changing the R4 (which is supposed to set the Vout along with the trim pot), but to no avail. With the trim pot and resistor removed, I got 100+ volts, but no matter how high value of a resistor I use I cannot get the output below 50v.
I am not a total n00b to electronics, but couldn't design a circuit myself or anything like that. I used basically everything from parts list on Tangent's website, not changing anything.
BTW if this helps here are the readings at the test points:
At 1 and 2: 37.3 vAC
At 5 and 3: 110.3! vAC, 50.3 vDC
At 4 and 5 (these equal output): 49.7 vDC
This is with a 470K ohms 1/2w KOA Speer (and the 500ohm trim pot removed).
I'll take more measurements with a NTE 2.2 ohm 2w resistor in place:
At 1 and 2: 37.7 vAC
At 5 and 3: 0.0 vAC? 50.7 vDC
At 4 and 5: 50.0 vDC exactly
I'm not skilled enough to read the schematic to find out what I did wrong. Another thing that is noteworthy: R5 is burning UP. It can't even touch it without burning myself, but that is when I had the 2.2 ohm res on there. It may have been trying to dissipate too much heat due to the low value of the other resistor though.
Thanks in advance for all your help!
I am not a total n00b to electronics, but couldn't design a circuit myself or anything like that. I used basically everything from parts list on Tangent's website, not changing anything.
BTW if this helps here are the readings at the test points:
At 1 and 2: 37.3 vAC
At 5 and 3: 110.3! vAC, 50.3 vDC
At 4 and 5 (these equal output): 49.7 vDC
This is with a 470K ohms 1/2w KOA Speer (and the 500ohm trim pot removed).
I'll take more measurements with a NTE 2.2 ohm 2w resistor in place:
At 1 and 2: 37.7 vAC
At 5 and 3: 0.0 vAC? 50.7 vDC
At 4 and 5: 50.0 vDC exactly
I'm not skilled enough to read the schematic to find out what I did wrong. Another thing that is noteworthy: R5 is burning UP. It can't even touch it without burning myself, but that is when I had the 2.2 ohm res on there. It may have been trying to dissipate too much heat due to the low value of the other resistor though.
Thanks in advance for all your help!