Transistor gain meter (CB20522E)

This circuit was found in a publication in the 1950s, mainly applying to germanium transistors of the time.

Laser Diode Modulator (CB4850E)
This circuit allows modulating a laser diode with low frequency signals. The integrated circuit...
Gain 100 with the 741 (CB902E)
This AC amplifier using the 741 operational amplifier uses a dual supply from 5 to 12 V. The input...
AC Phototransistor (CIR812E)
This circuit is suggested by the Optoelectronics Sourcebook by Texas Instruments when AC signals...