Unijunction SCR Trigger (CB21469E)

This unusual unijunction transistor SCR firing circuit was found in a General Electric documentation from the 1960s.

Sample and Hold LM3900 (CB14218E)
The circuit shown is suggested by National Semiconductor's Linear Applications Handbook. The base...
Telephone amplifier (CB8630E)
This circuit uses a pickup coil to take the signal from a telephone line without contacts. The circuit...
Opto and Strobe Interface (CB16037E)
In this circuit, the transistors are NPN for general use and the phototransistors can be replaced by...