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HP6268B Restoration

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AMR Labs:
I finally received the KSD-01 bimetallic thermal switches housed in a TO-220 package to implement the fan temperature control, instead of them running constantly which is both quite annoying and not necessary for my requirements as I will rarely push the power supply hard for a considerable amount of time.

Since both fans inside the HP6268B run on 115VAC, and even tough the metallic mounting flange of the switches seems to be adequately insulated from the switch itself, I was not entirely comfortable running 115V on the main A4 heatsink and to lesser degree at T1 the main power transformer. So I decided to build a small board with a tiny 12VDC converter that takes AC voltage directly, and two 12V relays that would be controlled by the thermal switches, one to control each fan.

For the A4 heatsink assembly I drilled a hole to mount the switch (60-C) directly onto the heatsink, and in the case of T1 I managed to just slip the switch (55-C) between two layers of the cardboard wrapping being careful not to disturb or scratch any of the transformer wingdings. Not sure yet if the temperature trip points of these two switches might need to be adjusted up or down depending on my usage. Guess I'll find out.

Bileeg:
I have a 6268B that was originally setup in 208 but I was able to configure to 230VDC but can't get it to set in constant voltage or current mode like described in the manual. All the jumpers are in across the terminals as recommended from the factory in normal mode as well. But when I disconnect one of the sensing leads The unit will drive to max voltage. Just as a test I placed a 12 vdc motor on the output as a load and the motor began to ramp up. the only way to control the output was to turn the over voltage screw counterclockwise but it did not go to zero just limited to 15 volts/3 Amps and the Over voltage light did not come on. Not sure what the issue is since I am just a novice at this kind of stuff. Thanks!

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