This circuit is from an American 1964 documentation. Transistors of the time are used, but modern equivalents can be employed.
We find this circuit in a 1987 publication. It makes use of comparators constructed around the 741...
Turns Ratio Between Windings Impedance Ratios 100:1 10 000:1 99:1 9 801:1 98:1 9 604:1 97:1 9...
This two-door doorbell was found in a 1990s US publication. The circuit is still current as...