This automotive grade circuit was found in a 1991 Electronics Hobbyist. The transistors are general purpose types. P1 sets the monitoring voltage.
This circuit triggers an oscillator when any of the sensors is opened. The circuit can be powered by...
This circuit imitates the singing of a bird intermittently with the intermittency determined by C1...
This is a high gain circuit with 3 transistors connected in direct coupling. The circuit is from a...