I have tested the PSU with mains and it all seems to be working.
The green wire on connector P2 when connected to the black wire, also on P2, switches the supply on.
It does not appear to need a minimum load on any of the supplies in order to start up. But I have got a 100R res on the standby supply anyway.
When the supply is connected to live mains but not activated the mauve wire, which I assume is the standby supply, has 11.4 volts. When PSU is activated (on) the voltage increases to 12.2v.
Neither of the trim pots make any difference to the voltage, but I believe the one I have identified as T1 sets a max amps for the main supply. If I turn it back then when a 1 ohm res is connected the PSU cuts out.
I have tested with a 1 ohm resistor and I am getting a good 9 amps out. (this is probably less then expected due to meter leads resistance) with a small drop in voltage from 12.3 volts (no load) to 12.14 volts.
The fan appears to come on full speed. It would be nice to make this smarter and vary speed depending on load.
There is no apparent warming of any heat sinks with the 9A load even though the case is open so the fan is having minimal effect. (I have only tested for a duration of about 2 minutes as the load resistors I am testing with get hot)
It would make a good supply for my needs if only I knew how to adjust the voltage.
Any help would be really appreciated.
Below are a couple of photos which are hopefully a little clearer. I have also edited a diagram I found on the internet with the pin details and colours.
Please let me know if any more photos of any particular part of the circuit are needed in order to help me.
Thanks
Mike
The green wire on connector P2 when connected to the black wire, also on P2, switches the supply on.
It does not appear to need a minimum load on any of the supplies in order to start up. But I have got a 100R res on the standby supply anyway.
When the supply is connected to live mains but not activated the mauve wire, which I assume is the standby supply, has 11.4 volts. When PSU is activated (on) the voltage increases to 12.2v.
Neither of the trim pots make any difference to the voltage, but I believe the one I have identified as T1 sets a max amps for the main supply. If I turn it back then when a 1 ohm res is connected the PSU cuts out.
I have tested with a 1 ohm resistor and I am getting a good 9 amps out. (this is probably less then expected due to meter leads resistance) with a small drop in voltage from 12.3 volts (no load) to 12.14 volts.
The fan appears to come on full speed. It would be nice to make this smarter and vary speed depending on load.
There is no apparent warming of any heat sinks with the 9A load even though the case is open so the fan is having minimal effect. (I have only tested for a duration of about 2 minutes as the load resistors I am testing with get hot)
It would make a good supply for my needs if only I knew how to adjust the voltage.
Any help would be really appreciated.
Below are a couple of photos which are hopefully a little clearer. I have also edited a diagram I found on the internet with the pin details and colours.
Please let me know if any more photos of any particular part of the circuit are needed in order to help me.
Thanks
Mike
