Found in 90s Popular Electronics, this circuit produces a modulated infrared beam for a remote phone whose circuit is shown right after it. Infrared LEDs are common.
Other operational amplifiers from the same family such as MC34002, MC35001, MC34004 and MC35004 can...
This oscillator uses germanium transistors. It was found in the Radio Electronics magazine of may...
This circuit is from a documentation on Motorola interfacing techniques from 1975. The Darlington may be...