While I was waiting for more parts to arrive, I decided to design the charge pump circuit. base upon the 2nd circuit here, I came up with this...


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It's using the 12v & 5v from the PC PSU to power the circuit and relay (4 pin 9090-4R connector, top left). I have included a fuse holder and LED indicator (JP1,2). The main 24v supply comes in on the left and will only be fed to the outputs (bottom) when the relay is energized, this should only happen when the PC is on and running Mach3.

There is a chance I might have the orientation of the 9090-4R connector wrong, so I need to double check this, once my part arrives, and before making the PCB. (This would swap the +12v & +5v lines)

I have also ordered some new CY cable as I plan to rewire the entire machine now. I will possibly need some new cable chains, so if anyone knows a good supplier, please let me know.

Regards,

Les