I (we) use neat little dual burner hot plates on kitchen counter. Last 2 units we purchased (from a GEnerally reputable company), have dinky temperature contol settings, that are now defunct. They are difficult to repair. So now I have 4 burners and no reliable control.
1) What I need is a 20A dimmer (like a light dimmer), I'll use to set my temperature, advise here would be ok. I'm easy with building stuff like that myself, but maybe something is available 'off the shelf'.2) Later, if necessary I'll put in a feed back from a thermistor, to set the temperature by duty cycling.
I should do #1 for the learning curve and see how it works 1st. Regards Ken