In the original publication of the 90s a 556 consisting of a double 555 is suggested. The circuit drives a speaker with good power. The power transistor shall be fitted with a heat sink.
Under this name, the popular electronic magazine of major/June 1969 introduced a simple...
This circuit was found in a 90s Radio Electronics. The FM encoder or multiplexer is an uncommon...
Found in an American publication from 1968, this circuit generates pulses at a rate of 2,500 per...