drum coil inductor


Joined Jun 22, 2012
It's a tapped inductor, for boosting the output voltage to drive the piezo, the primary side is about 22 ohms the secondary side is about 180 ohms, the centre tap goes to the positive supply.
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Thread Starter


Joined Mar 18, 2022
Circuit schematic is yet to be left to be made. I will update the schematic once I design.
But how to decide which center tapped inductor to use


Joined Jun 5, 2013
Where did you get the circuit? It is useless without knowing the soecs of the inductor, and that probably depends on what piezo disk you are using.

You know there are piezo buzzers with the oscillator built in, right?


Joined Aug 21, 2008
A) It is not necessarily center tapped. It can be tapped anywhere needed to get the desired voltage increase.
B) The wiring diagram in this simple case is almost as easy to read as a true schematic.


Joined Jan 23, 2018
Based on the data in post #6 it is certainly NOT CENTER tapped. It IS TAPPED, but far from the center.

For what it is worth, which may not be much, the piezo alarm sounders in two of my digital alarm clocks have DCplus AC supplied while alarm sounding. The DC portion seems to be about 6 volts, and the peak, DC+AC, is about 8 volts.
My intention is to get a louder alarm sound without a lot more hardware. (Not intending to hijack this thread.)