Test circuit with bridge (CB22530E)

This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from Radio Electronics June 1952.

Motorcycle Alarm (CB6487E)
We found this circuit in a Popular Electronics of the 90s. The MOSFET can be of any type,...
Amplifier for the Deaf (CB12866E)
In fact, the correct name would be a hearing aid amplifier. However, we use the name of the...
Relay Flasher (CB11965E)
This circuit controls a relay causing it to open and close its contacts at a speed that depends on the...