Longtime reader, second-time poster.
I have a Japanese MSX2 without a PSU, requiring 9VDC and 18VAC. The 18V is converted to ±12V (low current) for the cartridge port, while the 9V is regulated down to 5V. I’ve included a picture of an example PSU.
Previously, I bypassed the multi-voltage setup by providing 5V directly and using a ±12V DC-DC converter. (And deleting a lot of components in the onboard power circuit.) This time, I want to use the original PSU port and have a compatible connector from an old HP power supply. The system requires 9VDC, ground, and 18VAC on three pins.
Can I simply connect a regulated 9VDC PSU and an 18VAC PSU, tie the DC ground to one of the AC conductors, and fuse the other two connections (0.2A for 18VAC, 1A for 9VDC) to their respective pins? Or are there additional considerations for combining these power supplies to make it work?
I found a nice Jameco regulated DC PSU and another nice Jameco 18VAC PSU that look suited to the task.
Thanks, all!