Also, is there any need to protect the controller pin from the voltage spikes? And what about current draw, should I put a resistor because of the inductor, or can I expect small currents? Thanks a lot guys :)
On Tuesday, January 15, 2013 6:42:04 PM UTC+1, mikeselectricstuff wrote: > > On Tue, 15 Jan 2013 09:37:22 -0800 (PST), you wrote: > > >Hiya everyone! > > > >Does anyone have any simple schematic or any ideas how to amplify the > sound > >of a 2 pin piezo? > >For now I drive it simply from a controller pin, but the sound is > somewhat > >quiet for an alarm clock, so I'm looking for something different. > > > >Thanks! :) > > Put a 10-100millihenry Inductor across piezo ( you can get some very > cheap axial ones), and drive > withan open collector transistor, Note that disconnecting the piezo will > produce a high voltage > that may kill the transistor unless you use a HV transistor like MPSA42,. > if the piezo is solidly > connected you can usually use a bog-standard NPN as the piezo will limit > the voltage. > Also remember that piezos are sharply resonant so tweaking the frequency > for loudest output makes a > big difference, regardless of how you drive them. > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/qyn8fJq7J9EJ. For more options, visit https://groups.google.com/groups/opt_out.
