My Checkmate 1500 - A500 SFX form factor PSU design is complete.
Power (independently regulated):
- +5V @ 10A
- +12V @ 1.8A
- -12V @ 1.8A
- +5V Standby @ 200mA
Keyboard:
- Big-Box Amiga Keyboard input connector
- A500 Keyboard with reset output connector
- Power LED and Floppy LED output connectors
ATX:
- 119mm x 119mm, fits in SFX 125mm x 125mm
- PS-ON & PWR-OK signalling supported
- DC out connector on PSU side, to minimize internal power cable length.
Protection:
- 2A fusing on AC Line and Neutral
- MOV
- Over\Under voltage monitoring & Over-Temp monitoring with supply shutdown on fault.
- Temperature controlled fan
- RGB status LED for fault indication
- 4mm creepage for high voltage traces
I suspect the Checkmate 1500 Zorro II \ ATX board does not keep the Amiga A500 in RESET until the PWR-OK signal from the PSU indicates that the supply voltage has stabilized. I’ve asked for additional information about this behaviour from Steve. If it turns out that my hunch is correct; then since I have access to the A500 RESET signal, I will hold it low, until after the supply rails have stabilized and PWR-OK is driven high.
Gerber files sent to be fabricated July 4th
Schematic:
3D Model:
PCB Bottom Side:
PCB Top Side:
This is not a ‘product’ for sale
Once I’ve tested it, anyone who wants the design files will be welcome to them. My hope is that strong, clean power and good grounding will help to make an ACAxxxx and ZZ9000 equipped Amiga A500 reliable.