What is it?

OpenC64Saver is an Open Hardware implementation of the Computer Saver device developed by Ray Carlsen, mainly targeted at Commodore 64 users, but also usable on VIC-20 computers.

Why did you make it?

This over-voltage protection unit is designed to prevent damage to the Commodore 64 computer due to a failing power supply. One of the ways the Commodore "brick" power supply can fail is from a shorted internal 5 volt regulator. That fault puts excessive voltage into the computer and damages chips such as RAM very quickly... and silently. The Saver protector is essentially a fast-acting electronic circuit breaker. It functions to quickly cut off the 5 volt supply line to the computer if the voltage exceeds about 5.4 volts. This Saver is designed to protect any computer that uses the standard Commodore "brick" power supply as well as any newer switch-mode PS. Computers include all versions of the C64, the later CR version of the VIC20, and the Plus/4. - Ray Carlsen

What makes it special?

OpenC64Saver is Open Hardware. If you make any modifications to the board, please contribute them back.

What's included?

If you buy the component kit, this is what you will get:

• 1x220nF Ceramic Capacitor
• 1xZener Diode 4.7V
• 1x1N4148 Diode
• 1x3-pin Header Strip
• 1x3-pin Screw Terminal
• 2x2N3904 Transistor
• 1x820 Resistor
• 1x220k Resistor
• 1x2.2k Resistor
• 2x1k Resistor
• 1x5K Variable Resistor
• 1xSRD-05VDC-SL-C Relay

Please note that these kits require calibration: you will need to use a variable voltage source and a precise multimeter to set the cut-off point.

Disclaimer

OpenC64Saver is provided to you 'as is' and without any express or implied warranties whatsoever with respect to its functionality, operability or use, including, without limitation, any implied warranties of merchantability, fitness for a particular purpose or infringement. We expressly disclaim any liability whatsoever for any direct, indirect, consequential, incidental or special damages, including, without limitation, lost revenues, lost profits, losses resulting from business interruption or loss of data, regardless of the form of action or legal theory under which the liability may be asserted, even if advised of the possibility or likelihood of such damages.

Get Help

If you need help or have questions, you can join the official Telegram group.