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.
Source :: http://www.zen22142.zen.co.uk/Circuits/Alarm/buzzer.htm
Related Links
More small speaker circuit
More about buzzer sound circuit
Mini Metronome by 555
Simple Metronome using transistor
small Metronome using 2N3904
Simple light sensitivity Metronome using 2N3904
Door buzzer with 555
Self-Resonance Piezo Buzzer with 1-18V
Simple Electronic Bell Generator using LM741
This entry was posted on Sunday, June 24th, 2007 at 12:23 am and is filed under Audio - Alarm, basic electronics, Circuit diagram.
