DIY Kit OVPC64 V1.1 Overvoltage Protection for Commodore 64 Power Supply EXT IN

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

This is a DIY KIT OVPC64 V1.1 Overvoltage Protection. (soldering and drilling skill needed)

It comes with all the electronic components and a high quality PCB board. This kit would be great for those experienced in both electronic soldering and drilling, while building something useful and having fun.

Please do not buy this kit if you do not feel comfortable in soldering and drilling, you need to make the holes on the plastic box included. For adjusting trip point you will need a Power supply with adjustable voltage and current.

A step by step guide for assembling is provided (Pdf file for downloading)

When fully assembled, tI have 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 OVPC64 monitors 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 electromechanical devices (relay). Unlike the overvoltage protection included in most power supplies this one acts very fast and precise.

The 9VAC line is protected using a PTC Polymer fuse which offers 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) or Commodore VIC-20 CR from overvoltage on the 5VDC line.

· 1.25-2 A fast fuse that disconnects the 5VDC line in case of overvoltage condition.

· 2 LEDs indicating the status of 5VDC line: OK or LOW when it is lower than 4.75V.

· 1 LED indicating the status of 9V AC line.

· Can be reset by unplugging the power source. In case of overvoltage condition on 5VDC line, you may 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 requirements for power adapters

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

· Recommended 2-3A. If you buy cheap ones on eBay 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 adapter 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 questions, 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.

Small differences in color or shape with the components shown in picture may happen, but do not affect item functionality. The provided labels are white. Original Commodore power supply, power adapter and tools not included, just for reference.

Tested with 3 original C64 power supplies, C64 breadbin, C64C and 4 differents 5V DC adapters, one of them 5V 2A from ebay ($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 ebay triggers the device at startup, but can be used by switching it on before connecting.

DIY Kit OVPC64 V1.1 Overvoltage Protection for Commodore 64 Power Supply EXT IN

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