This circuit can be used as an answering password system in a store, office, or other location. The circuit is from Intersil using components of the time. The circuit is from the 80's.
This circuit has already been explored in other articles on this site. The high power is due to...
This circuit was found in a computer publication from the 1970s. The transistors can be the BD135...
This triac circuit was taken from an article in the July 1970 Radio Electronics magazine. Note the...