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 solutions & design ideas.

Got Designs?
Please eMail
if you want me to link to and/or post your original design
NOTE:  We make every effort to link to original material posted by the designer. 
Please contact us if our link is not to your site!  Thanks.

DiscoverCircuits.com -- Hobby Corner
Last Updated on: Tuesday, June 01, 2021 03:06 PM

Hobby Circuits List

The contents & graphics of Discovercircuits.com are copyright protected.
LINK to Dave's circuit, but DO NOT COPY any files to your WEB SITE server

More  Laser Circuits

GaAIAs Laser Diode Test Circuit

designed by David Johnson, P.E.

I do a lot of optical electronics work.  Often I need to test a modulated light detector hobby circuit at a particular frequency.  The device below has come in handy many times.  I can adjust the frequency of the modulated infrared laser light from about 10KHz to over 50MHz.
 The light from the laser can be directed toward the detector using a plastic fiber optic light pipe, connected to the laser.

The CA3140 circuit forms a laser light power control circuit, using the PIN photo diode inside the laser assembly.   The photo diode collects a bit of the laser light launched producing a current at the 3.3K resistor, which is proportional to the laser light power. The circuit maintains a constant bias current through the laser. 

The 74HC14 circuit is a combination of an oscillator and a laser driver.  The driver increases and decreases laser diode current, producing light pulses matching the oscillator signal. This electronic circuit can be used with visible red laser diodes as well infrared.


Click on Circuit Below to view PDF of Schematic

GaAIAs Laser Diode Test Circuit, March 20, 1999

More  Laser Circuits

Hobby Circuits List
eMail David A. Johnson, P.E. about this circuit

HOME Schematics Index Hobby Corner Dave's Circuits Contact Info
Imagineering Ezine Dave Johnson & Associates Faraday Touch Switches

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

Copyright  January, 1998 - June, 2021     David A. Johnson  All Rights reserved. 
 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.