This circuit was found in 1960s Radio Electronics. The circuit uses components from that time. The triac is according to the controlled load. The sensor is a common LDR.
This circuit generates frequencies determined by R3 and C1. We found it in the Radio Electronics magazine...
The configuration below is suggested by the National Semiconductor Linear Applications Handbook. The...
This charger circuit provides an initial voltage of 2.5 V and when the current reaches 180 mA the...