controlling AC phase (AC dimming light)

[fitri]

Hi all,

i want to ask is anyone here have done controlling AC phase using arduino?
i try to do AC dimming light. my idea is just use the same program for dimming DC light. the problem is that i dont know the circuit. does anyone have the circuit? and do you all think my idea will work?

please feel free to give you opinion.

tq very much

[ABSF]

Are you talking about the mains 230V AC or some stepped down AC through a transformer. If you're trying to dim the lamp connected to 230V ac mains, you have to take precautions as the 230V will destroy the mcu if you're not careful. But still it is possible to do it through opto-coupler. I cant find any example using Arduino but there is one for the 12F615 PIC. The principle is the same.

picdccontrolleddimmer_1272130733.png (10 KiB) Viewed 3613 times

The article is here
http://pcbheaven.com/circuitpages/PIC_D ... AC_Dimmer/

Allen

[shahrul]

Input GP2, I think for phase detector, either the AC source is positive cycle or negative cycle.

[ABSF]

i try to do AC dimming light. my idea is just use the same program for dimming DC light. the problem is that i dont know the circuit. does anyone have the circuit? and do you all think my idea will work?

As you can see from the circuit. Dimming AC light is different from dimming DC light.

To dim AC light, you need to start cutting the sine wave at a fixed point e.g. at the points where the sine wave crosses the zero axis. But to dim DC light you just need to have a continuous PWM wave with different duty cycles to a MOSFET to control the brightness.

Allen

[fitri]

to dim up and dim down, we just control the duty cycle right? if want to off the light, we need to cut the circuit.
correct me if im wrong.

the circuit i not really understand to construct it with arduino...

[fitri]

Hi guys..
do you all think i can just refer to this circuit?

one more thing..what we call the symbol 4 diode all connecting in the circuit?

http://www.levinegabriella.com/2012/01/ ... r-circuit/

tq

[ABSF]

one more thing..what we call the symbol 4 diode all connecting in the circuit?

That thing is called a "rectifier bridge".

I wouldnt recommend the circuit to you unless you are an expert in electronics. The separation between the AC and DC is of minimum design. You can get electric shocks when testing or constructing the circuit. And besides, where are you going to get the +5V for the mcu, you'll need a stepdown transformer or an adaptor anyway? Can you just substitute the 110V ac and 110V lamp with 220V ac and 220V lamp ?

Take a look at the datasheet of IRF250 here;
http://www.bmo.physik.uni-muenchen.de/~ ... IRF250.pdf

Allen

[fitri]

Thank god you mention this for me
herm...so how you recommend?

i want to control AC dimming light using digital button on arduino

thank you..

[ABSF]

i want to control AC dimming light using digital button on arduino

In the circuit that I posted, you can replace the PIC with the Arduino. GP2 is a digital input, GP4 is analog input and GP5 is digital output. You can add 2 more buttons on the arduion as digital inputs for UP and DOWN function. So the rest are just software. Once your software is working, you can always remove the analog input.

The assembly program for PIC is included in the website and you have to understand it and convert it to the Arduion C for it to work.

OR Google search again for one that work with arduino with the HW similar to the one that I posted. Knowing just one programming language would be tough to get things done even with internet.

Allen

[fitri]

Hi,

tq for the advice.

so do i need to use zero-crossing opto-coupler?
to dim the light am i need to use Digital Output?
are the program i need to is some kind like this :
eg: 50% dim
on signal 10ms
off signal 10ms