welding voltage into plc

[baileybane]

Is it possible to step down electrode to ground potential for use as an analog input? Welder is ~70ocv and ~40ov.
Be gentle
Thanks,

Jason

 

[djs]

You might be able to lower the voltage using a voltage divider resistor network. The other alternative is to use a voltage regulating IC. The voltage for an analog current input should be 24VDC or less.

However anaother problem occurs with many welders. The output is not filtered, so has considerable ripple. This will affect the noise in your analog signal.

Another problem is that many welders use a inductor in series with the output. This will cause very high voltage surges when used as a welder.

 

[Macbeth]

What are you doing? Are you trying to regulate the weld?
I ask this for there may be alternatives. Maybe current draw would be better then would know when the welder was in use.
As far as measuring voltage a PT (Potential Transformer) of adequate size should work.

 

[electrageek]

Call RIS (Rochester Instruments) or Action Pak or Mighty Module one of them should have a transducer that will convert whatever your field voltage is to a PLC type signal (0-10Vdc) or (4-20ma). You can find them on the Web.

 

[wired1]

There is a company called Digimetrics in MA that makes weld monitoring equipment. They have gadjets that integrate voltage or current that the welder delivers to the part and can provide a pass/fail signal to a PLC.