This sensitive two-transistor circuit was found in the June 1965 Radio Electronics magazine. The circuit has low drift and uses an analog instrument. The input resistance is high.
We found this configuration in a 1974 technical documentation. It can test both TTL logic circuits and...
This circuit emits an alert sound (interval beeps) if the car lights are left on and the ignition key...
This is an amplifier that uses a pickup coil placed next to the telephone set and the listening is done in...