This type of answering machine was common at the time this circuit was published. Using two tape recorders, it was published in the June 1986 issue of Radio Electronics magazine.
The integrated 4017, a C-MOS counter, is one of the most popular in the design of sequences,...
This simple very low power circuit can be used in a battery powered infrared tone trigger. We...
This timer controls two relays, each with a different timing, activated separately. The circuit is from...