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


DiscoverCircuits.com -- Hobby Corner
Last Updated on: Thursday, November 30, 2017 07:43 AM

Hobby Circuits List

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  Control Circuits   Hour Meters    Testers

CT Hour Meter  --  February 13, 2010 
 

Many systems require routine maintenance based on machine operation time.  The circuit below is a simple way to turn on a hour meter whenever AC power is supplied to the machine.  An inexpensive snap-on current transformer from Magnetics Inc, is used to detect the AC current.
The output of the transformer is fed to a voltage doubler circuit.  When 0.5 AC Amps or more of current is flowing, the circuit generates sufficient voltage to turn on the n-channel MOSFET.  Once tuned on, the transistor routes voltage to the hour meter.  Some hour meters contain their own battery, so no external power is needed. 

In those cases, the transistor switch alone will turn on the hour meter.

Magnetics Inc CR3110-3000
Current Transformer
Hour Meter Hour Meter
 

Click on Drawing Below to view PDF version of Schematic



More  Control Circuits   Hour Meters    Testers

Hobby Circuits List
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.