Found in American documentation from the 1980s, this circuit prolongs the ringing of a doorbell or chime powered by a 6 V continuous voltage. The transistor can be a BD136.
The first circuit, shown in the figure, generates a stepped signal whose frequency depends on the...
This differential amplifier, found in a 1964 Electronic Design, has a gain of 30. The setting can be...
The purpose of this circuit is to control the high and low light of a car, detecting when a...