Selecting a switch/relay for spark-free switching?
I have a plasma cutter without a pilot arc and would now like to convert it to a pilot arc.
For this, I got a hose package with pilot ignition. It contains an additional cable—I'll call it the pilot cable.
For the pilot ignition, I would now like to use a switch/relay to short-circuit the pilot ignition to the ground connection in the plasma cutter, as this is how the plasma jet is ignited.
For this purpose, I integrated a 12 V power supply into the plasma cutter so that a button on the torch can switch a relay. I want to disconnect the pilot wire from the ground connection after ignition. The plasma cutter can handle up to 40 A of cutting current.
Now to my question, or rather, my problem: I've already tested a mechanical relay and an SSR relay. Both stopped working very quickly. The contacts on the mechanical relay stick together, and the SSR also switched on continuously after the test.
Why did both relays fail and what can I do to implement my project as cheaply and compactly as possible?
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now with an SSR relay you are already on the right track.
However, this must be designed both at voltage level and maximum current as well as current form alternating/equivalent current.
Furthermore, it needs cooling area where you attach the SSR so it doesn't get too hot as it still has some watt loss power.
In order to find a suitable one would need all data from the circuit, especially the current
I measured the short-circuit current beforehand and this is at a maximum of 40 A. I took an SSR for direct current at 60 A. Unfortunately, this didn't work…
I suspect that perhaps at the moment of ignition, a higher current might flow in the short term.
Since no one has responded, I just wanted to tell you that you need a corresponding transducer because otherwise the anode is constantly exuding you and you also have to have the electrostatic forces of the mass.
Can you explain that?
You've got to compensate for shooting. I recommend a Schauberger's vertebrate. Or a repulsine.