This circuit was found in a 90s Popular Electronics. It is used for the acoustic transmitters of 40 kHz, as several found in this section. Transistors support current equivalents.
Touching the sensor with your fingers, this circuit produces a machine gun sound. The circuit must...
August 2017 - STMicroelectronics' BlueCoin development environment is available at Mouser...
We found this circuit in an old documentation. Its purpose is to turn on warning lights when the...