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aaronik19
Joined: 25 Apr 2011 Posts: 297
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Lamp Test of AC leds |
Posted: Mon Jul 31, 2017 8:12 am |
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Dear Friends,
I know that this is not an electronic forum but I have a difficulty and I really wish your help since some might know the answer and be useful to someone else. I am building a circuit and the user need to make a lamp test to test the panels LEDS which operates at 24VAC. In dc I usually make a diode in the input of the diode and another diode from the signal to the input of the diode to avoid false triggering. On AC how I can solve the problem?
Thanks for your understanding.
Yours |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19369
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Posted: Mon Jul 31, 2017 10:20 am |
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Honestly you question is not very clear. However I suspect an AC input opto-coupler, with a resistor across it's inputs, selected so it turns on when the right current is drawn, might do what you want. |
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Mike Walne
Joined: 19 Feb 2004 Posts: 1785 Location: Boston Spa UK
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Posted: Mon Jul 31, 2017 10:25 am |
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Like you say this one's strictly off topic.
As usual your'e not giving us much to work on, but you might consider:
1) Relays.
2) FETs.
Mike
Partly depends on whether one side of the ac can be connected to PIC negative rail.
Big question. Are the LEDs providing a signal TO or responding to a signal FROM the controller? |
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aaronik19
Joined: 25 Apr 2011 Posts: 297
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Posted: Mon Jul 31, 2017 2:37 pm |
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Mike please stop criticise everytime i ask question. If you are not confortable to answer my question, just my question. Other people responded and i am very pleased with their reply. If you read my post i started the post that my question is not related to pic but it might be useful for someone who might use ac with pic.
What is wrong???? |
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temtronic
Joined: 01 Jul 2010 Posts: 9174 Location: Greensville,Ontario
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Posted: Mon Jul 31, 2017 4:36 pm |
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Along with the other suggestions
you could optically couple the panel LED to a sensor to confirm it's on.
you could measure the current of the panel LED to confirm it's on.
Without knowing what access you have to the LEDs it's difficult to say whih is the best approah.
Also how many LEDs need to be tested and how many PIC I/O pins ae available, how much memory is commited to the test function?
I know how to test up to 32 LEDs with one I/O pin, old school ,BTDT 3 decades ago...still works to !
Jay |
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Mike Walne
Joined: 19 Feb 2004 Posts: 1785 Location: Boston Spa UK
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Posted: Wed Aug 02, 2017 2:34 am |
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aaronik19 wrote: | Mike please stop criticise everytime i ask question. If you are not confortable to answer my question, just my question. Other people responded and i am very pleased with their reply. If you read my post i started the post that my question is not related to pic but it might be useful for someone who might use ac with pic.
What is wrong???? |
I started by agreeing with you!
I can't answer your question simply because I still don't understand EXACTLY what you are wanting to do, so I'm probing further.
For example:-
When I start-up my car ALL the fail indicators light during the start-up sequence.
Even when there are no faults, the test allows me to see all the LEDs are functional.
Are you wanting a test like this, or something else?
Mike
It might help if you supply a drawing. |
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