We found this circuit in a 70s Electronic Design documentation. The circuit uses general-purpose transistors from the time. Linearity is better than 0.25%.
This circuit triggers by burning an input fuse when the monitored voltage exceeds 5 V. The SCR...
This circuit activates an incandescent lamp (or LEDs) when the light stops hitting the sensor, which...
The CK722 transistor used in this circuit is one of the first commercial types in the world. The...