Thyristor firing+PLC

[osamamalhy]

Good day every one
Can any one help to do Thyristor firing for wilding machine using the PLC?
is there any ready module for that?
iam uasing the siemens controller
Regards
Osama

 

[LadderLogic]

Generally speaking, PLCs are not fast enough to do this kind of work - this has to be done with some kind of hard-wired electronic circuit. That is, if you want to use your own home-built thyristor circuit.

However, if a thyristor bridge (or an SCR bridge, or a transistor bridge) is a part of a VFD (variable frequency drive) or a servo drive, a PLC can work with those: by commanding the drive to run at certain speed or at a certain torque value and receiving feedback from the drive. Depending on the drive model chosen, there are many ways to do that.

 

[leitmotif]

What kind of welding are you doing?
What is arc duration?
What is weld completion time?

IF it were just spot welding for a single setup where you just throw a bunch of amps at the material for one or two seconds a PLC may work fine.

If it is a robot TIG or wire feed then PLC control of the weld circuit may not be fast enough ESPECIALLY if you want to control the high freq component (if used)

Dan Bentler

 

[waggs]

Firing a thyristor...

Entertron makes a world full of welding controllers...