I'm trying to revive an old microwave oven that has a fried PCB. I've searched online for a similar PCB but couldn't find one that works. I'm looking to build a timer circuit that allows me to set the cooking time with a knob, and start the microwave with a button. Ideally, I want the knob to adjust the time from 0 to 60 seconds, and then from 1 to 10 minutes. Additionally, I'd like to have a feature that turns the microwave on and off every few minutes for better cooking. Does anyone have schematics or tutorials to help me get started?
2 Answers
Just a heads-up, there are some significant safety concerns with modifying microwave circuits. I suggest you read a 2018 article by Asokan Ambali on Electronicsforu.com which discusses control boards for microwaves. It's more complex than it seems since there are important safety interlocks to consider. Make sure to grab a service manual for your specific model to understand the control lines and interlock paths before starting your project.
You should consider checking out timer kits on sites like Aliexpress. It's probably not a good idea to make your own using something complicated like a rotary telephone dial. Keep it simple and safe!
It might not be an option for where I live, but thanks for the suggestion!
I appreciate the warning, and I will definitely integrate all safety switches in my design. But I’m looking for something much simpler than the project in that article.