This simple circuit found in a 1968 EEE was intended for data transmission over the telephone line. The components are from that time, some are uncommon today.
This network can be used in a sound project to control the tone. The circuit is from an...
This fast-acting circuit uses any phototransistor as a sensor. The circuit drives a 30 V relay, but...
This 1kHz filter with Q = 10 can be applied to any operator. The power supply is symmetrical and...