This circuit activates a buzzer when the voltage applied to the input falls below a preset value in R1. The circuit is from an 80's American documentation.
The circuit in the figure is a current regulator with adjustment in the range of 0 to 3 amps. The...
This filter with the operational 741 passes the frequency range between 300 Hz and 3,400 Hz. This...
Taken from an Electronics Now from the 90s, this circuit generates signals whose frequency depends on...