scr voltage adjustment

[will albert]

hello all this is my first post so be gentle thanks . now im needing to design a 100amp 120 volt power suply i already have the transformer and a big bridge rectifier already assembled, i also have some very big scrs now i was wondering what would be the best way to go about it , it needs to out put some fairly high current, as im wanting to test DC to AC inverters with it, instead of using this horrible battery bank ,and if it could charge the batts it would be great ,ok im rambleing on a bit now,but it doesent realy need to be regulated and a big variac is too expencive and i dont think my work would fork out the cash for one i was thinking of using a normal light dimmer to control the scrs but im not too sure if it will work and i am also not to sure if the scrs will work at all in this application HELP!!!. sorry about the spelling

 

[ericgibbs]

hi,
If you have 'big' scr's why dont you make a scr bridge in place of the standard diode bridge and control the firing angle of the scrs in the bridge.?

The output from the bridge [dc] would charge a big cap..

Is this what you had in mind,?

 

[Roff]

hi,
If you have 'big' scr's why dont you make a scr bridge in place of the standard diode bridge and control the firing angle of the scrs in the bridge.?

The output from the bridge [dc] would charge a big cap..

Is this what you had in mind,?

And only two of the 4 diodes need to be replaced with SCRs.

 

[will albert]

thanks for that guys, thats what i was sort of doing today i was playing around with a 555 timer to try and drive 1 scr today but had no luck i had it conected straight to the scr via a resistor , than i tryed using a cap , i smoked my 20v power supply then fixed it and i tryed a little transformer i made but no luck, there is one prob with this cct as i dont have the spec for the scr they are made by ge i should have written down the number on them but i just wanted to get out of the joint tonight, i think the power supply smoked because of the way the other service tech had hooked up the cro but its still stumping me, the idea you have sounds good but i am not to clued up on scrs and the way the work, they seem a bit confusing i thort i had nutted it out untill today.

 

[ericgibbs]

thanks for that guys, thats what i was sort of doing today i was playing around with a 555 timer to try and drive 1 scr today but had no luck i had it conected straight to the scr via a resistor , than i tryed using a cap , i smoked my 20v power supply then fixed it and i tryed a little transformer i made but no luck, there is one prob with this cct as i dont have the spec for the scr they are made by ge i should have written down the number on them but i just wanted to get out of the joint tonight, i think the power supply smoked because of the way the other service tech had hooked up the cro but its still stumping me, the idea you have sounds good but i am not to clued up on scrs and the way the work, they seem a bit confusing i thort i had nutted it out untill today.

hi,
There are lots of circuits, Google for ' scr bridge '

As Roff says, you can simplify the bridge.

**broken link removed**

**broken link removed**

 

[will albert]

thanks for all your help guys its been a big help i will get back to you and let you know how i go