Found in Popular Electronics from the 90s, this circuit is based on a PLL567 and employs high-end or ultrasonic speakers depending on the frequency of oscillations.
This circuit allows the use of two triggers (inverters or NAND ports connected in this way) to...
This circuit was found in a 1992 publication. Its purpose is to time the activation of a doorbell...
A fine adjustment of the output voltage of a power source is achieved with this circuit, which...