I do not give a definite brand of “936” because I have a lot of varieties, because there are many kinds of cyber 936 beb 936 and so on 936 etc … what is the same number 🙂 heat control circuit 24V AC power control installed on lm324 opamp bt137 is done via triac, 24v, so there is no need for additional power source. Temperature control between 200 … 450 degrees ..