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Digitally controlled light dimmer switch

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May 10, 2011
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I am a current student working on an electronics project. My professor has instructed us to go on the web and find a schematic on a digitally controlled light dimmer switch using a triac. After a few hours of searching I have found nothing that even remotely looks like what my professor is asking me to find. I was hoping someone on here would be able to direct me to where I can find such a thing.

What I know is that the circuit needs to contain a DAC, Optocoupler, and a triac. From what I understand the circuit is to be controlled by a bank of digital switches which feeds into a DAC to convert the digital signal into an analog signal. Then I am guessing that signal gets fed through an op amp then through an opto coupler which then is tied into a regular light dimming circuit.

If anyone knows anywhere where I can find more information on such a circuit I would be extremely grateful.


yes you use the following circuits thanks,
i think it may helpful
**broken link removed**
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PWM is in deed superior, but not when a Triac has to be used! I think phase control is what is expected in this challenge.
Thannara123 - check your math! The figures you quote in the "Duty Cycle..." paragraph are quite wrong.


Just to highlight :

Despite the title of above topic I sugested refers to PWM control. in fact. the Application Note quoted at that link does not really implements exaclly that kind of control.


This may help **broken link removed**

Semitone is an open dimmer project and its the best I'm aware of. Crystal is a single channel dimmer, Diamond is a 20 channel (multiple types) multi-protocol dimmer running custom RTOS. The whole project gives in-depth knowledge about dimming, I've built and used more than half a dozen Crystal dimmers without any issues.

Hope this helps.

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