Novel Buzzer
Designed by Tom.
This novel buzzer circuit uses a relay in series with a small audio transformer and speaker. When the switch is pressed, the relay will
operate via the transformer primary and closed relay contact. As soon as the relay operates the normally closed contact will open, removing
power from the relay, the contacts close and the sequence repeats, all very quickly...so fast that the pulse of current causes fluctuations
in the transformer primary, and hence secondary. The speakers tone is thus proportional to relay operating frequency. The capacitor C can
be used to "tune" the note. The nominal value is 0.001uF, increasing capacitance lowers the buzzers tone.
