In the figure we have a simple thermometer with NTC, using an analog current indicator. The adjustment is made in the trimpot and the power is done by batteries.
In this circuit the signal from the phototransistor is amplified by a Darlington stage and then...
This simple half-wave control using an SCR, which may be TIC106, has been obtained from a US...
We found this circuit in Radio Electronics from October 1968. The circuit drives headlight bulbs...