This circuit was found in Radio Electronics from the 90s. The CMOS integrated circuit is a PLL not easy to obtain today. The output stage can be exchanged for another one with greater power.
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...
This configuration, widely used in our articles and on this website, uses a 555 to control a relay...
This circuit was found in an English documentation from the 90s. It uses a PLL CMOS 4046 and is...