35 Online
1 Member And 34 Guest
Members present at the site
Today Visits : 12765
Yesterday Visits : 19906
All Visits : 1381625

Welcome to Electronoobs Q&A, where you can ask questions and receive answers from other members of the community.


0 like 0 dislike
My questions are based on this project   http://www.electronoobs.com/eng_circuitos_tut20.php

I have built your AC triac dimming circuit with a potentiometer, and 110VAC 60Hz mains voltage.  The first time I ran the program, the lamp dimmed properly.  However, once I turned off power and turned in on again, the lamp did not turn on.  I changed out the optocoupler it fixed the problem, but it happened again.  I placed my oscilloscope across D8 (connected to the EL817 optocoupler) and GND and measured a sine wave.  I understand this should be a square wave, which is what I measured when the lamp actually dimmed.

Can you please help me understand why I am getting a sine wave across D8 and ground?  Why does the circuit work once and then stops working when I go to use it again?  How can I prevent these issues from happening in the future?  

Thank you in advance
in Arduino by (120 points)

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.