Voltage level detector (CB21504E)

This circuit was found in a 1966 EEE. The circuit can be implemented with modern general-purpose transistors.

Non-Inverter Amplifier LM139 (CB14247E)
The presented circuit uses a symmetrical power source to supply an amplifier with the LM139 or...
Light Activated Pulsing Alarm (CB26243E)
This circuit was obtained from the 1995 Encyclopedia of Electronic Circuits Volume 5. The circuit...
Sinusoidal Generator (CB14356E)
The circuit shown is from the 1994 Linear Applications Handbook by National Semiconductor. Some of...