Written in an article in Radio Electronics magazine in April 1987, this circuit triggers an alarm via a relay. Details of the sensor are given in the article.
With this circuit it is possible to divide the frequency of a rectangular signal by values between 2...
This circuit, which we find in a documentation from the 70s, filters out the Ru [occurring in...
This circuit simulates the call tone of a telephone. The transducer is a high impedance capsule, and...