How does a home light intensity circuit work ?

[ScOe]

Hi,

How does home light intensity circuit works ? It has potentiometer, but does it have some kind of PWM inside or it is current regulated via variable resistor ?

If i want to use PWM what can i use on high current side ? Can anyone post some schematic ?

I want to control light intensity upon some criteria which will be calculated in uC. The light is on 220V side, so i need some kind of opto isolation.

 

[Faizan Jawaid]

Re: Home light intensity

U have to use an SCR to control the current of a 200VAC light... Changing the firing angle of phase will increase or decrease its intensity... Use google for light dimmer circuits.

 

[flatulent]

Re: Home light intensity

These circuit radiate a lot of noise in the LF and MF AM broadcast bands. If you like listening to distant stations, these dimmers will ruin your reception.

 

[RF-OM]

Re: Home light intensity

Such circuit depends heavily on the type of lamps. If you use incandescent lamps it is simple and you may use zero-crossing detection circuits and SCRs. Be careful with phase control for these lamps because they have very high inrush current. But if you need to regulate fluorescent lamps it is much harder to do. There are a lot of electronic circuits for such applications. Both of these way creates a lot of electrical noise, especially for fluorescent lamps. Any lamps have small regulation band (incandescent have wider band, but any way you do not use week lights). You may check Crydom web site. They have some ready to go proportional regulators of very high quality for incandescent lamps.

 

[ScOe]

Re: Home light intensity

I was looking on net for light dimmers and come to this page:
http://www.ivica-novakovic.from.hr/Lightdimmer-eng.htm
I need to control light intensity of 50 watt halogen lamp.
Something like: MR16 2-PIN HALOGEN FLOODLIGHT BULB - 50W

Is it possible to do it with that dimmer circuit ?