This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
This circuit monitors the humidity of a pot or plant bed, providing indication on two LEDs. The...
This “zero crossing detector” was found in a manual of operational amplifiers from the 1980s....
This narrowband data receiver is from the Philips Databook of 1990. The circuit is powered by 5 V...