The figure shows how to implement a filter against interference caused by the switching of a triac. The circuit is from a Radio Electronics from April 1987.
This circuit of a 1978 American publication monitors a telephone line by triggering a relay. The...
When S1 is in 1, the circuit operates with of half the total power applied to the load. When in...
This power supply also has a fine adjustment feature. The transformer is 16 + 16 V with 3 A and...