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Joined: 8/26/2008(UTC)
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Location: Raleigh, NC
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I built two Placid BP and one Placid positive power supplies for my Buffalo32. I purchased the PC boards from TP and the parts independently from Mouser and Digi-Key. I obtained -+ 15V and after shorting R6 and R15 on the I was able to get 250ma output. However I amd not able to reduce the voltage on the positive Placid below 8V when the VR4 is maxed out at 2K. Voltage across C2 is 10.5V and I am using both secondaries in parallel of an Antek AN-0209 (9V 25VA).
Should I replace VR4 with a larger trimmer or increase the size of R10?
Roy
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You can reduce the value of R10. Try 470R-1K.
The schematic as shown will only go down to about 8V.
The reference is about 4V.
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Rank: Member
Groups: Member
Joined: 8/26/2008(UTC)
Posts: 5
Location: Raleigh, NC
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Thanks Russ,
I placed a 634R resister in parallel with R10 with dropped the total resistence to 481R. I then adjusted VR4 to 960R and was within .2 volts of the target 6V.
Has the BOM changed for R10 in your kit?
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