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Author Topic: Ohmic Sensor - HOW?  (Read 7130 times)

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Ohmic Sensor - HOW?
« on: July 05, 2012, 04:43:38 PM »
I want to use this option in my plasma table machine, anyone know what is required to use this option?

« Last Edit: July 05, 2012, 04:58:52 PM by Johnny Storm »
Re: Ohmic Sensor - HOW?
« Reply #1 on: July 05, 2012, 10:00:43 PM »
To do it right, you need two relays.  The contacts on relay 1 will connect to the wire you see on the ohmic sensor and to the coil (-) on relay 2.  The coil (+) on relay two goes to 24V or whatever voltage you're using for relays.  Connect the contacts on relay 2 to the input on your bob you use for "probe".

The first thing you'll do when you want to fire the torch is to close relay 1.  This makes continuity from the ohmic sensor to relay 2 so when the torch touches ground, relay 2 closes activating the "probe" signal.  Before the torch fires, close relay 1.  If you don't...and the arc jumps to the ground cap (ohmic sensor)...and it will...you will send 150+V to the ohmic sensor relay.  The purpose of relay 1 is to isolate the ohmic sensor completely while the torch is fired.   

When you go to HF arc start, you have to go even further as the HF will jump the contacts in relay 1 like it's not even there.
Re: Ohmic Sensor - HOW?
« Reply #2 on: July 05, 2012, 10:13:11 PM »
To do it right, you need two relays.  The contacts on relay 1 will connect to the wire you see on the ohmic sensor and to the coil (-) on relay 2.  The coil (+) on relay two goes to 24V or whatever voltage you're using for relays.  Connect the contacts on relay 2 to the input on your bob you use for "probe".

The first thing you'll do when you want to fire the torch is to close relay 1.  This makes continuity from the ohmic sensor to relay 2 so when the torch touches ground, relay 2 closes activating the "probe" signal.  Before the torch fires, close relay 1.  If you don't...and the arc jumps to the ground cap (ohmic sensor)...and it will...you will send 150+V to the ohmic sensor relay.  The purpose of relay 1 is to isolate the ohmic sensor completely while the torch is fired.   

When you go to HF arc start, you have to go even further as the HF will jump the contacts in relay 1 like it's not even there.


Thank you very much :)
Re: Ohmic Sensor - HOW?
« Reply #3 on: March 29, 2016, 11:35:39 PM »
 :)
« Last Edit: March 29, 2016, 11:51:26 PM by sandeep.1033 »