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The Great Search: Positive to negative 12V power inverter for Apple 2 disk drive bias

The Great Search: Positive to negative 12V power inverter for Apple 2 disk drive bias

Adafruit Industries

February 15, 202212m 29s

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Show Notes

The Apple Disk ][ drive is a converted Shugart drive that has three power supplies: 5V, +12V and -12V. The 5V and 12V are for the motor control. Negative 12V is a bit of a pain to generate, but thankfully the -12V seems to only be used for biasing a trim potentiometer. So, we don't need a lot of current. Still, we do need to generate -12V, let's take inspiration from the classic MAX232 RS232 driver chip to find a charge pump converter! See on Digi-Key at https://www.digikey.com/short/5w04zzr2 Visit the Adafruit shop online - http://www.adafruit.com ----------------------------------------- LIVE CHAT IS HERE! http://adafru.it/discord Adafruit on Instagram: https://www.instagram.com/adafruit Subscribe to Adafruit on YouTube: http://adafru.it/subscribe New tutorials on the Adafruit Learning System: http://learn.adafruit.com/