This circuit was found in an Electronic Design from 1964. The components are from that time and can be replaced by equivalents. The modulation ranges from 0.25 to 0.75 of the 20 kHz pulses.
We found this circuit in an English documentation from 1995. With it it is possible to measure a...
This circuit is from an ancient American documentation. The coil is frequency dependent and the...
We have here a simple signaling circuit for two common incandescent lamps, which is used for...