You could build my one!
It's been going strong since 2016. An Arduino and a few bits and pieces. Feedback control of heater, so you just start it up and never have to think about it. I've got some updates which I should upload - includes a PC interface if you are so inclined. I use nichrome wire for heaters.
http://www.iceinspace.com.au/forum/s...d.php?t=144679
https://github.com/ChrisV77/Telescop...aterController