Found in American documentation from the 90s, this circuit triggers a buzzer with a Sonalert-type oscillator when the temperature of the sensor reaches a certain value set in R2.
Found in ancient documentation, this circuit uses a high voltage transistor of the time. Observe...
This voltage inverter uses a small transformer. The circuit was found in the April 1995 issue of...
We found this circuit for musical instruments in the March 1992 Radio Electronics magazine. The...