Hello,
I needed two power supplies for electroplating. So I bought two kits from Ali. I bought them separately from two suppliers because I realized I needed second one after buying the first.
I build them both on the same day but they both have similar problems.
I use a 24v AC transformer and installed the supplied 5v1 zeners. After building them both I started to test them but I couldn't adjust the 0 volt as described in the manual. With the voltage and current pots on 0 ,I turned the trimpot RV1 all the way up and down on both boards and the output voltage doesn't change? The current limiting indicator LED is on all the time and I need that LED to work.
If I use my adjustable AV transformer on one board the current limiting indicator LED starts working on 22v on the other on 17V. The opamp's are fitted on a socket and I changed them around without changing the simptoms.
Can anybody point out what could be wrong? If more info is needed I will provide.
I needed two power supplies for electroplating. So I bought two kits from Ali. I bought them separately from two suppliers because I realized I needed second one after buying the first.
I build them both on the same day but they both have similar problems.
I use a 24v AC transformer and installed the supplied 5v1 zeners. After building them both I started to test them but I couldn't adjust the 0 volt as described in the manual. With the voltage and current pots on 0 ,I turned the trimpot RV1 all the way up and down on both boards and the output voltage doesn't change? The current limiting indicator LED is on all the time and I need that LED to work.
If I use my adjustable AV transformer on one board the current limiting indicator LED starts working on 22v on the other on 17V. The opamp's are fitted on a socket and I changed them around without changing the simptoms.
Can anybody point out what could be wrong? If more info is needed I will provide.