OVPC64 V1.1 Overvoltage Protection for Commodore 64 power supplies including external DC & AC inputs.

The OVPC64 is an overvoltage protection device for Commodore computers using 5VDC and 9VAC power sources. Original epoxy filled PSU\'s are prone to fail due to heat & age, then the 5VDC line receives 9-12 Volts burning the expensive chips inside your C64:SID, RAM, VIC, CPU, CIAs..

The OVPC64monitors the 5VDC voltage and automatically disconnects it when it rises above the trip voltage. It uses solid state devices, providing a faster protection than similar protectors using electromecanichal devices (relay). Unlike the overvoltage protection included in most power suplies this one acts very fast and precise.

The 9VAC line is protected using a PTC Polymer fuse which offer a resettable overcurrent protection.

This new version includes 2 external inputs so you can use power adapters for the 5V DC and/or 9V AC line. The external adapters are also protected. You can use the original power supply for the 9VAC that usually does not fail and use a 5VDC adapter for the 5V DC line or using 2 external adapters.

Features

· Protect your Commodore 64(C/G/GS/Aldi) orCommodore VIC-20 CR from overvoltage on the 5VDC line.

· 1.25 A fast fuse that disconnects the 5VDC line in case of overvoltage condition.

·2 LEDs indicating the status of 5VDCline: OK orLOWwhen it is lower than 4.75V.

·1 LED indicating the status of9V ACline.

· Can be reset by unplugging the power source. In case of overvoltage condition on 5VDC line, youmay need to change the fuse. (Spare fuse included)

· Trip point adjusted at 5.45V, may be changed to your choice.

· External inputs for 5VDC or 9VAC power adapters.

Input requeriments for power adapters

· 5V DC 1.5A minimum 5.5 x 2.1/2.5mm. positive to centre (AKA positive polarity or Tip Positive).

· Recommended 2-3A. If you buy cheap ones on or Aliexpress be careful, most of them are undersized and will give low voltage or problems at startup. Very low cost SMPSs may couple electrical switching noise back onto the AC power line, causing interference with Audio/Video equipment and any other electronic equipment connected to the same AC phase. I can not guarantee to work with all of them, some dirty cheap will cause an overvoltage at startup and trigger the device, but your C64 will be protected. Using a branded power adaptor is the best: RS, MeanWell, CUI, D-Link...

· 9V AC 1A 5.5 x 2.1/2.5 Nintendo NES power supply is known to be good. Be sure it is AC voltage NOT DC.

· For C64C lower power could be enough, 9V AC 0.5 or 0.75 Amps should be enough.

Any question, please ask before buying, thanks.

Notice that this device will reduce the fail rate of your C64 but it can not guarantee your C64 will never fail, it is very old hardware.

DIN plug can be black or grey.Original Commodore power supply or power adapter not included, just for size reference.

Tested with 3 original C64 power supplies, C64 breadbin, C64Cand 4 differents 5V DC adapters, one of them 5V 2A from ($2.5) gives low voltage warning and runs really hot but C64 still working, the other 2 (5v 1.2A D-Link and 5V 2.4A DVE) worked well and a 5V2A PCB SMPS from triggers the device at startup, but can be used by switching it on before connecting.