Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


Circuits designed by David Johnson, P.E.
Last Updated on: Thursday, November 30, 2017 07:43 AM

Master Category List - Dave's Circuits

The contents & graphics of Discovercircuits.com are copyright protected.
LINKING to Dave's circuits is permitted but DO NOT COPY any files to your WEB SITE server

More  Beepers & Buzzers;    Piezoelectric
 

Very Loud Pulsating Beeper Keeps Average DC Current Draw Low
 

Many battery powered alarms draw excessive current when operating.  Some of the most attention-getting noise makers, such as the unit shown below, use piezoelectric sound generators with a frequency sweeping tone.  When operating with a 9v battery, these units can often draw 100ma or more. In many applications, a continuous alarm sound is not needed.  Locating a balloon or a rocket are examples where you want a loud sound but a low average power drain.  To lower the average current, the device can be pulsed with short 0.05 second chirps, once every two or three seconds.  This lowers the average current by a factor of 60.  So, instead of drawing 100ma, by chirping the alarm, the current is lowered to just 2ma.  The circuit below generates the pulse train needed for these short but very loud chirp sounds.
   
  Pulsating Beeper  

 

Click on Drawing Below to view PDF version of Schematic


More  Beepers & Buzzers;    Piezoelectric
 

List of Dave's Circuits
Dave's Circuits with Descriptions
Dave's Circuits by Category

eMail David A. Johnson, P.E. about this circuit

 


HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy


Copyright  January, 1998 - November, 2017     David A. Johnson & Associates.  All Rights reserved. 


 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.