Full wave rectifier for piezoelectric supply

Thread Starter


Joined Feb 15, 2009

My project involves rectification of a voltage produced by a piezoelectric stack subjected to an impact. The voltage shall be rectified using a full wave bridge rectifier.

I aim to use a capacitor (in position of the smoothing capacitor) to store the energy harvested from the impact (simply because the device must fall from a certain height so it cannot be connected to any measuring equipment during its descent). The capacitor shall be disconnected following impact and connected to a volt meter so stored energy can be calculated.

My question is: does anyone have any suggestion as to how I can calculate required capacitor value? I have no idea of the frequency, current or voltage of the piezoelectric stack output, and these are likely to vary for different impacts.

I do know the voltage and current I require from the rectifier output - if that helps!

Any help would be greatly appreciated




Joined Aug 7, 2008
Please share any information that you have ie. " I do know..." . Speculation: Stack falls with Bridge rectofier and cap attached ?
With so many unknowns are you allowed to experiment with values?
One possibility: use a capacitor voltage divider to transferr charge from stack to measuring site. Values given are pure speculation , just be sure to use no leakage caps or at least low leakage ones, like polystyrine.