AC fuses, switches and relays are generally rated higher for AC usage than DC usage. I understand that is because the AC wave crosses zero, which will turn off any DC arc. So DC fuses are often spring-loaded to open a bigger gap to stop the arc. My little relays say they're good for 10A @ 30V DC, or 10A @ 250V AC.
Now I'm driving DC that is PWM chopped (with a guarantee that it will always be zero for part of the period). Would the AC reasoning apply - arcing will stop, so an AC fuse could work, or maybe we can safely pump more chopped DC through a switch (even at high duty, but not 100% duty cycle). I'm looking at 10kHz to 20kHz chopping, and I'm guessing any DC arc should die down in microsecs. (Or does the plasma hang around and the arc might survive a too-short interruption?)
The question is more for insight than deployment right now - I'm just trying to appreciate some of the boundaries and trade-offs.
Thanks
Now I'm driving DC that is PWM chopped (with a guarantee that it will always be zero for part of the period). Would the AC reasoning apply - arcing will stop, so an AC fuse could work, or maybe we can safely pump more chopped DC through a switch (even at high duty, but not 100% duty cycle). I'm looking at 10kHz to 20kHz chopping, and I'm guessing any DC arc should die down in microsecs. (Or does the plasma hang around and the arc might survive a too-short interruption?)
The question is more for insight than deployment right now - I'm just trying to appreciate some of the boundaries and trade-offs.
Thanks