Transistorized Voltmeter (CB21916E)

We found this circuit in a Raytheon manual from 1956. The transistors are germanium of the time, and the accuracy depends on the resistors.

Photosensitive power circuit (CB25193E)
This circuit can be used in alarms by activating a relay or a current load that depends on the...
LM3900 Non-Inverter Comparator (CB14207E)
The circuit given below was found in the National Semiconductor Linear Applications Handbook. The...
Phototransistor Currente Control (3) (CB14641E)
The current of this circuit is determined by a PNP transistor. The circuit is suggested by Texas...