jhnn
Posts: 9
Joined: Fri May 25, 2018 12:39 pm

PWM AC Dimmer

Mon Aug 13, 2018 9:52 pm

Hello everyone

I am looking to use a PWM AC dimmer like this one on the picture below.
The idea is to vary a 220 V fan.
I would like to predict 5 speed: 1 min speed, 5 max speed.

I do not find much info on this subject.
Can I connect this card to the raspberry pwm outputs (pin12, pin32, pin33) ??

As for the script, I am absolutely nil. I would like to create 6 scripts:
0 => OFF
1.5 => Speed from 1 to 5

But I do not know how to do it.

Do you have any ideas on this?

Desolate for my english, google translated for me :D

PWM AC DIMMER :

Image

wh7qq
Posts: 1059
Joined: Thu Oct 09, 2014 2:50 am

Re: PWM AC Dimmer

Tue Aug 14, 2018 4:59 am

Your picture is nice but it provides no information on the nature of the device or how it controls the AC. Further, there is no information about what kind of input it requires. If you want help, you have to give us some information about how this board hooks up or even if it does connect to the RPi.

jhnn
Posts: 9
Joined: Fri May 25, 2018 12:39 pm

Re: PWM AC Dimmer

Tue Aug 14, 2018 7:30 am

Hello,

Here are the info found on the seller's website.
Here are the links of the page http://www.electronicnuts.com/2ch-ac-le ... smart-home

And here are the features from the board:

I hope this information is sufficient

AC Phase Control Circuit (Dimming Circuit)

Module contains two Triacs with zero-cross detector for programming the intensity of incandescent lamps, AC LED dimmable bulbs, heating elements or fan speed controlled through a micro-controller.

Working AC voltage 80...240 VAC.
Auto detect 50Hz or 60Hz.
Zero-Cross detection (with zero/cross output pin SYNC).
Compatible with any ARDUINO, RASPBERRY boards.
Low voltage side and high voltage side is completely isolated.
Dimensions of the PCB 90mm x 60mm.
Four mounting holes diameter 3.2mm.
Connected LOAD power for each channel 5A.
NOT appropriate to change the brightness of fluorescent lamps !!!
Control dimming level via FIRING ANGLE method !

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Tue Aug 14, 2018 11:11 am

First of all, by the looks and the information you are providing in you opening post. Do you have any knowledge this subject*. Because one little mistake will kill you.
With that said. I saw that you ask this questing a couple of times. So, if you don't have the knowledge to build it, it's probably a better idea to buy a complete module with the correct certificates for your country.

Back to you question:

Can you tell us, what the different, or not, is between this:
  • Control dimming level via FIRING ANGLE method !
  • PWM AC dimmer (as you called it)
Because this is probable one of the imported part of you dimmer.

And do you know also what "Zero-Cross detection (with zero/cross output pin SYNC)." this means for you?

*Yes, if have read that you know how to connect (correctly) to means power, but do you know how to design it?

wh7qq
Posts: 1059
Joined: Thu Oct 09, 2014 2:50 am

Re: PWM AC Dimmer

Tue Aug 14, 2018 5:00 pm

The "features" list specifically states AC control by phase control. NOT PWM. "Control dimming level via FIRING ANGLE method !"

The description also lists Arduino demonstration code...this does not translate to RPi without considerable tinkering in the code.

The triac inherently switches off at zero volts.

This board has some utility but it is expensive and will probably either electrocute or start a fire in the hands of inexperienced users.

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Tue Aug 14, 2018 7:52 pm

wh7qq wrote:
Tue Aug 14, 2018 5:00 pm
The "features" list specifically states AC control by phase control. NOT PWM. "Control dimming level via FIRING ANGLE method !"

The description also lists Arduino demonstration code...this does not translate to RPi without considerable tinkering in the code.

The triac inherently switches off at zero volts.

This board has some utility but it is expensive and will probably either electrocute or start a fire in the hands of inexperienced users.
Yes, its indeed not for a inexperienced user.
I also think that the raspberry pi is not the best solution to control this kind of application. Because, if a other process takes the to much time* (or crashed), you will be in trouble. Thereby I would advice to use a dedicated microcontroller. That only controls the AC dimmer, and its gets the command by a serial interface.

Or buy a module that is designed for this.

*I don't exactly how the processes works inside the pi.

jhnn
Posts: 9
Joined: Fri May 25, 2018 12:39 pm

Re: PWM AC Dimmer

Thu Aug 16, 2018 8:53 pm

Ok thanks for the information.
I will then go to an Arduino to control this kind of module.
If I connect an arduino in usb on my pi, can I drive it via scripts.
Basically the fan speed should vary according to the temperature measured by the pi.

Like this :

https://www.tindie.com/products/bugrovs ... 50hz-60hz/

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Thu Aug 16, 2018 9:13 pm

Let's take a couple steps back. You want to use a switch? with multiple positions to control the fan. Or do you want to connect it over the internet.

And to set things straight:
The switching elements, triac in this case, need to be controlled by a microcontroller. And he also need to obtain information about the inputvoltage. And this microcontroller get from a other device, pi, ne555, or?

And now you show a product link with a microcontroller on it. So, what are you using know.

Or is it better for you to buy a finished product?

edit
I personally think you should buy a official dimmer. Than you now for sure that you won't burn you house down. Because I don't think you have the right knowledge about this subject. Also I found about that a real dimmer is not much expensive as the kit you want to buy. And you could possible hack into the office one. For example, if that product have a potentiometer, you could control the position by a servo. That is controlled by your pi

PhatFil
Posts: 390
Joined: Thu Apr 13, 2017 3:55 pm

Re: PWM AC Dimmer

Thu Aug 16, 2018 9:35 pm

fwiw years ago i tried to control a small a/c clip fan with an off the shelf light circuit dimmer switch which could handle a load greater than the fan would draw (About the limit of my a/c power knowledge at the time. And i dont know much more now...)

the result was less than pleasing it didnt work very well, when turning up from the off position the fan stood still and just hummed loudly until it finaly started to spin at about 60-70% round the dial, and then it was basically on and the control was iffy at best.

further reading led me to understand there are different motor types and some respond to different control methods better.. so i would suggest start at the fan and its motor and determine how best to control it and then look at what solutions are available to interface between it and your pi.

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Fri Aug 17, 2018 2:13 pm

More information about the motor would also be nice.

If you think you ar capable of making a dimmer. I think you should buy this in stead of the one from ebay. As you can see in the pictures and in the manual its contains more crucial components like a filter and fuse. This kit is designed by a "well" know company. And not "someone" from ebay. And the price is almost the same :D However like PhatFil says, its depends what kind of motor you are using.

The other option is to choise a other fan with a regulation input. Like the one that bortek is using, like his one.


Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Fri Aug 17, 2018 6:48 pm

jhnn wrote:
Fri Aug 17, 2018 5:19 pm
Here is the fan https://www.globalairsupplies.co.uk/rvk-125-l1
Okay, do you think it's possible to control this fan motor. Now we are giving you some advice, for for module / kit / product are you want to use to control your motor?

PhatFil
Posts: 390
Joined: Thu Apr 13, 2017 3:55 pm

Re: PWM AC Dimmer

Fri Aug 17, 2018 7:44 pm

jhnn wrote:
Fri Aug 17, 2018 5:19 pm
Here is the fan https://www.globalairsupplies.co.uk/rvk-125-l1
a few clues in the link..
Speed Controllable (Triac or Voltage)
Thermal Protection
Energy efficient, backwards curved motorised impeller
The impeller is balanced dynamically in two levels to reduce vibration and noise
Casing made of extremely durable 30% fibreglass reinforced polypropylene
Suitable to ventilate damp or even wet rooms: IP44 rated terminal box
Includes mounting bracket
Maintenance free and reliable quality
Made in Germany
now i am wadding way out of my depth here but the above would suggest that there are 2 main types of control you should focus on.
Triac or Voltage

But that your probably only going to be able to run it at 100% and one other level without it humming and vibrating anoyingly

a cheap ?voltage? control system may be derived from a resistance controlled ssr https://www.ebay.co.uk/itm/SSR-10VA-10A ... Sw9NdXqzQQ
(the type driven by a 500k/linear pot (electric guitar volume knob) accross its control terminals providing a dial up/down power controller, my experience with such h/w is limited to the control of elements in my nano brewery when used to control power to 3kw heating elements, the cheap voltage/amp meter i have wound into the circuit displays a a/c voltage drop along side the amp output drop.. if this is the same sort of voltage control as suggested by the link ?? i do not know. a standard ssr switched via pwm could be just as good/bad?

how you would wire up/configure a pi to control such an ssr is also beyond my current scope, i would probably look at a cheap out of the examples folder solution perhaps using a dirt cheap stepper motor to turn the physical pot ;)
https://www.ebay.co.uk/itm/Smart-Electr ... SwqVJaxSdX
im sure the electrical engineers reading this are feeling the pain..

edit btw ebay links are not recommendations of sellers or brands, just the first example found and copied in as a link.
Last edited by PhatFil on Fri Aug 17, 2018 7:50 pm, edited 1 time in total.

jhnn
Posts: 9
Joined: Fri May 25, 2018 12:39 pm

Re: PWM AC Dimmer

Fri Aug 17, 2018 7:47 pm

Actually, I use this dimmer to control the Fan.

When i put the dimmer at the min, they give me 100 V
When i put the dimmer at the max they give me 230 V

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Fri Aug 17, 2018 7:59 pm

PhatFil wrote:
Fri Aug 17, 2018 7:44 pm
how you would wire up/configure a pi to control such an ssr is also beyond my current scope, i would probably look at a cheap out of the examples folder solution perhaps using a dirt cheap stepper motor to turn the physical pot ;)
https://www.ebay.co.uk/itm/Smart-Electr ... SwqVJaxSdX
im sure the electrical engineers reading this are feeling the pain..
Brandon92 wrote:
Thu Aug 16, 2018 9:13 pm
edit
I personally think you should buy a official dimmer. Than you now for sure that you won't burn you house down. Because I don't think you have the right knowledge about this subject. Also I found about that a real dimmer is not much expensive as the kit you want to buy. And you could possible hack into the office one. For example, if that product have a potentiometer, you could control the position by a servo. That is controlled by your pi
At least the servo voltage is save to use. And you don't play with the means voltage ;)
jhnn wrote:
Fri Aug 17, 2018 7:47 pm
Actually, I use this dimmer to control the Fan.

When i put the dimmer at the min, they give me 100 V
When i put the dimmer at the max they give me 230 V
What is "this"? And how did you all connected and programmed. Please give us a little bit more information to help you...

drgeoff
Posts: 8440
Joined: Wed Jan 25, 2012 6:39 pm

Re: PWM AC Dimmer

Fri Aug 17, 2018 9:18 pm

PhatFil wrote:
Fri Aug 17, 2018 7:44 pm
But that your probably only going to be able to run it at 100% and one other level without it humming and vibrating anoyingly
I think that "two levels" is a bad translation from the original German and was meant to mean two axes or two directions or something like that. Not that the fan will hum or vibrate annoyingly at other than two speeds.

jhnn
Posts: 9
Joined: Fri May 25, 2018 12:39 pm

Re: PWM AC Dimmer

Fri Aug 17, 2018 9:40 pm

Sorry, here is the dimmer that i use from 5 years

https://www.amazon.fr/Prise-Variateur-d ... B0058CIHWS

Brandon92
Posts: 404
Joined: Wed Jul 25, 2018 9:29 pm
Location: Netherlands

Re: PWM AC Dimmer

Fri Aug 17, 2018 10:44 pm

jhnn wrote:
Fri Aug 17, 2018 9:40 pm
Sorry, here is the dimmer that i use from 5 years

https://www.amazon.fr/Prise-Variateur-d ... B0058CIHWS
Unfortunately does't provide you link any information about your current dimmer. Other than a image.

PhatFil
Posts: 390
Joined: Thu Apr 13, 2017 3:55 pm

Re: PWM AC Dimmer

Fri Aug 17, 2018 11:40 pm

drgeoff wrote:
Fri Aug 17, 2018 9:18 pm
PhatFil wrote:
Fri Aug 17, 2018 7:44 pm
But that your probably only going to be able to run it at 100% and one other level without it humming and vibrating anoyingly
I think that "two levels" is a bad translation from the original German and was meant to mean two axes or two directions or something like that. Not that the fan will hum or vibrate annoyingly at other than two speeds.

As usual im thankful for the clarification, Cheers.. i admit i jumped to an unfounded conclusion there..

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