This circuit was found in the October 1987 Radio Electronics magazine. The circuit is a PWM control with a 555. It appears that the 555 is missing a connection that would be pin 4.
Found in documentation from the 1970s, this circuit uses an oscillator and a display to warn of...
This circuit simulates a low-level siren and can be supplied with voltages from 5 to 15 V....
The filter shown in the figure, using only an operational amplifier, is characterized by allowing 1...