dimmer switch using scrs..

hi guys.....please help me with the theory on dimmer switches using 2 scrs..i searched the net ....could not find anything convincing......please explain me in a simple way...i was just taught the basics of scr....so.................please help me...it is important for me...it has to use scr's.......pleaseeeee

 

You use 2 SCRs back to back as if you are using a triac and that is the basic of it.

 

Well here's one I designed earlier..

I use these to control from 15 Watts to 20Kw (dependent on SCR).

If you want the PCB layout, let me know>>

Daniel.

 

You may benefit from reading the material available on the AAC website that contains an SCR Tutorial.

hgmjr

 

Hi lightingman.
i need the circuit 2x scr that u posted before. May u post again that circuits?
Thanks

 

The link to the PDF still works. The thread, however, is 3 years old.

 

When were you born dude?

 

Hi!

I´m having a slight problem with Lightingmans circuit and would appreciate some help

The problem is; I get an "control" puls roughly 14 degrees in to Q1 and Q3 but can´t control it´s position despite changing the control voltage from just above 0 to 10 volts. see pic



First of, I have replaced some of the components to some I had available at the time;
TR 1,2,3 -> BC548C
TR 4 -> BD241C
ZD 2,3 -> to two 6v2 diods in series

Am I wrong to asume that this shouldn´t cause the problem?

Any ideas to what I have done wrong?

Cheers // Tomas

 

Mods, can u move this to a new one.