This circuit mimics the heartbeat with the softest sound played through a small speaker. The circuit is from an Electronics Now issue of January 1997.
This circuit is from an October 1963 Radio Electroncs. It uses a single 2N18383 transistor and a...
We found this circuit in a 1972 RCA technical documentation. The comparator can be any type and C1...
Found in a 1970 EEE this circuit emulates a zener diode whose voltage can be set to R2. Power...