No Arc. Understanding 4 Relay Module + Proma THC.

[Rodw]

Sorry, I got that wrong. its not the THC but impedance to ground on the input pin on your control hardware. In my case that was quoted in the board manual so a friend who is more versed in electronics than I calculated the required resistor value and the power rating after I located the data sheet for the relay Everlast used. I don't know that you could measure it. If all else fails try my value. Just keep plenty of air around it as it might get hot.