Here we explain how to modify a USA 115V SC503 Maxi Controller to operate at 230V.
I have successfully completed this modification four times, however, and I accept no responsibility for the effects of anyone making these modifications. You follow these instructions at your own risk.
To modify the Maxi Controller, follow the following instructions:
- Remove the four screws at the bottom of the unit and take off the bottom cover.
- Remove the screw in the middle of the PCB, and remove the PCB keeping the top of the unit on the tabletop.
- Scrape off the epoxy glue by the big blue capacitor being careful not to break the fuse wire. Replace this capacitor with a 1uF 400-volt device.
- Replace the smaller capacitor with a 100nF 400-volt device.
- Remove the 22-ohm resistor, and stand it on end in one of its mounting holes; add another 22-ohm resistor in series with it.
- The 275-volt varistor has been soldered underneath the circuit board across the incoming 230V mains supply, but after the fuse.
This picture is pre-modification.
This picture is post-modification.
If you attempt these modifications, please let me know your results, and read the warning on the X-10 and 115V & 230V page.
Comments received at Redoak
- In Jan 2009, Eddy Kok from Singapore confirmed the modifications worked.
- In Feb 2010, I had a report from muzzag50 in Australia that the modification worked.
ps - this is a really easy modification! John