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Topic: SSR PWM` (Read 2 times) previous topic - next topic

0AlphaOmega

The term Solid State Relay covers several semi-conductor devices that are used to switch a load electronically, thus a Triac, SCR, Thyristor, etc. even MOSFETS can be described as SSR. Indeed, I suppose that you could extend that to any transistor or any 'black box' that replaces a mechanical relay.

Buying an off the shelf device is a valid method (I've not tried it, but I would think that hitting it with a 590Hz PWM would be a bit hit and miss without tying it to the mains frequency, but then that depends whether it has additional circuitry to manage this). Using a Diac removes the need for other power supply.

I would imagine that since arduinohabib is on a microprocessor forum, and hasn't opted for a light dimmer from his local electrical factors, he is looking to learn how to do it himself. That is why I suggested a method that he can research and try, thus expanding his understanding of AC voltages, switching devices, timing etc. He can of course pick and choose the method to follow. It's all fun, and many have us have already been there many times over.

One lesson for him to learn, is to understand exactly what he wants to achieve, what the bounds are and then to explore ways of accomplishing this.

As an aside, arduinohabib, one might consider using an SSR with a mechanical relay (not in a dimming, but in a pure switching mode of course). The advantage of this is that the load begins to switch at zero volts and the SSR need only be quite small as the mechanical relay is in parallel and will take the full load within a cycle or two (relays tend to take about 20ms to pull in), and the relay suffers little or no arcing across the contacts, reducing pitting and extending life. (switching off gracefully is a little more complicated)

Again - Take care with mains
For whom does the clock pulse? It pulses for you!

Grumpy_Mike

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The term Solid State Relay covers several semi-conductor devices that are used to switch a load electronically, thus a Triac, SCR, Thyristor, etc. even MOSFETS can be described as SSR.

No it is not.
The term Solid State Relay covers ready built modules that could consist of anything, however generally they have opto isolation and full wave control. They may or may not incorporate phase control circuits. Some even work with DC and are in effect FETs. But they are all modules not discrete components.

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but I would think that hitting it with a 590Hz PWM would be a bit hit and miss without tying it to the mains frequency, but then that depends whether it has additional circuitry to manage this

Yes feeding raw PWM into a SSR is not going to work. No one said it would. I was suggesting filtering the PWM to give smooth DC to feed into phase controlled SSRs. If you misunderstood what I said then please re read it.

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I would imagine that since arduinohabib is on a microprocessor forum, and hasn't opted for a light dimmer from his local electrical factors, he is looking to learn how to do it himself.

When you have a bit of experience with this forum you will know that most beginners just want a solution. If the know about a soloution but want to do it themselves they generally say so.
As he says:-
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I really want to be able to PWM my 220v ac lights.

He is not very up on the theory of these things, which is fine but is a good indicator of the answer he needs.

lizhenan

you can search  motor speed controller  "dianji tiao su qi"  on   taobao.com     It change resistance to control the TRIAC's conduction Angle
haha

arduinohabib

No sure I'd like to learn the theorys--I don't want you to tell me just how to do it. Of course I want to know how it works, and I am willing to experiment and experience failure. Thanks.
PS @lizhenan I think I want to do it myself. Do you live in China?
What is man's best friend? The breadboard!

lizhenan

yes,I am in China , there are a lot of Schematic on Google ,You can search the keywords to find them
haha

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