SSR control of ?AC induction coil

[jessoman]

Hi all,

I have used SSR'S in the past without issue.

I have an induction cook top and I have disconnected the coil that does the heating and ran it through the load side of the SSR.

It turns on once on initial signal from the microcontroller signal to the SSR, but when I send a low signal / turn the SSR off. The induction coil keeps getting powered and the SSR doesn't unlatch. ALSO within only a few minutes of running the thing goes well over 100 *C and deformed the plastic.

The SSR light goes on and off but the coil remains heating, so I don't believe it's an input / control issue.

The cooktop is 240vac 15Amp.

I haven't just connected into the power button to turn it on and off because I want to pre set the power setting in the cook top board and it doesn't remember it it I turn it off and back on that way. I also don't want to overcomplicate it and write a switch to "push" multiple buttons.

Combining my beginner knowledge of electronics and my research, I think it is something to do with the "zero cross trigger method" & something to do with the waveform voltage/current mismatch, meaning zero point is never hit, which stops the thing from releasing. Is this right?

What is a simple & cost effective way of fixing this? I would like to PWM this coil, so I believe SSR is the go (more accurate power control of the coil). I don't think a mechanical relay would be suitable....

SSR:
https://www.ebay.com.au/itm/324173952564?chn=ps&norover=1&mkevt=1&mkrid=705-139619-5960-0&mkcid=2&itemid=324173952564&targetid=1281061181725&device=c&mktype=pla&googleloc=9068929&poi=&campaignid=10101784997&mkgroupid=117859315410&rlsatarget=pla-1281061181725&abcId=9300367&merchantid=115560435&gclid=CjwKCAjw7rWKBhAtEiwAJ3CWLDQBc1W3ttu_jNFNnzYw3XHwcdnTHiIFKahX1a8O-zvqs3dq7TrrzxoCKyMQAvD_BwE

Induction
https://www.internationalcatering.com.au/product/induction-cooker/


Also, here is the cookers circuit diagram for the smart cookies. If any smart cookies can think of a way to "highjack" the circuitry to achieve this. With this, I would be happy to be able to turn the device on/off at max power.
https://cdn-ice2018.pressidium.com/wp-content/uploads/2011/08/ICK3500-WIRING-DIAGRAM.pdf

Thanks for reading!