It's a technical question. Does anybody here know about these stoves?
I recently picked up a used Defy stove with glass top (Ceran). Since I worked with a heat test chamber that uses halogen lights for elements, I was intrigued by this kind of stove. For an electric element, they heat up very quickly. But I soon discovered that heat regulation is not good. I think the problem is with the design of the temperature control. The temperature control knob uses a thermo-electrical setup (bimetal strip) to control power to the element. Essentially, it switches the element on and off, with longer periods of on as you adjust the temperature higher at the knob. This works OK with spiral plates and solid plates. With spiral plates, maximum temperature is fairly OK; with solid plates, the thermal mass of the plate evens out temperature fluctuations. But the problem with halogens is that the maximum temperature achieved is exceedingly high. So, although the turn-on/turn-off action happens, the pot gets periodically hot enough to burn the contents, even on the lowest setting. It looks like they are using the same temperature control scheme on all types of plates!
Now, I want to build my own temperature controller, using electronics. It shouldn't be too difficult, but I would like to know if anyone here knows something that I should be aware of. The plate uses infra-red radiation as its primary means of heating, with some conduction and convection also in the mix. You can see the plate glow luminously red. If, at the lower temperatures, I regulate the heater such that it does not glow, will it affect the functioning (efficiency)?
I recently picked up a used Defy stove with glass top (Ceran). Since I worked with a heat test chamber that uses halogen lights for elements, I was intrigued by this kind of stove. For an electric element, they heat up very quickly. But I soon discovered that heat regulation is not good. I think the problem is with the design of the temperature control. The temperature control knob uses a thermo-electrical setup (bimetal strip) to control power to the element. Essentially, it switches the element on and off, with longer periods of on as you adjust the temperature higher at the knob. This works OK with spiral plates and solid plates. With spiral plates, maximum temperature is fairly OK; with solid plates, the thermal mass of the plate evens out temperature fluctuations. But the problem with halogens is that the maximum temperature achieved is exceedingly high. So, although the turn-on/turn-off action happens, the pot gets periodically hot enough to burn the contents, even on the lowest setting. It looks like they are using the same temperature control scheme on all types of plates!
Now, I want to build my own temperature controller, using electronics. It shouldn't be too difficult, but I would like to know if anyone here knows something that I should be aware of. The plate uses infra-red radiation as its primary means of heating, with some conduction and convection also in the mix. You can see the plate glow luminously red. If, at the lower temperatures, I regulate the heater such that it does not glow, will it affect the functioning (efficiency)?
