Obtained in a 1968 Electronics World, this circuit uses transistors from the time and the sensor is a common LDR. The component values are for scales from 0.01 to 100 foot-candle.
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
The circuit shown is a reference of -10 V with a maximum current of 50 mA obtained from the Linear...
Found in a 1980s American documentation, this circuit can use a SCR and a general-purpose transistor....