This circuit is one of many of its kind that can be found on this site. This one is from a September 1987 Radio Electronics. The triac must be controlled according to the load.
This simulated circuit on the NI Multisim transmits modulated infrared signals with the audio...
This circuit is from a 1976 publication, but it can be easily implemented with a BC548 transistor. The...
This circuit for very long-time intervals was found in the March 1993 Radio Electronics magazine. Times...