This alarm with automatic shutoff was found in the April 1975 Radio Electronics magazine. The activation time is given by C1 and R3. The alarm uses series and parallel sensors.
This transmitter emits signals in the FM range, reaching a few meters away. The modulation...
This audio amplifier has an internal DC volume control with logarithmic characteristics and a...
This configuration found in GE documentation from the 90s, can also be seen elsewhere in this...