I know this is true, but have always wondered if there was set "ratio" between ratings AC vs. DC. In other words, if you know the AC voltage/current rating, can you calculate the DC rating, or vice versa? Or, is it not that simple?AC has a zero volt crossing, so the arc is much easier to break. DC never crosses zero, so the voltage that a switch will break reliably is far lower.
I know this is true, but have always wondered if there was set "ratio" between ratings AC vs. DC. In other words, if you know the AC voltage/current rating, can you calculate the DC rating, or vice versa? Or, is it not that simple?
So the bottom line is look mainly at the DC rating.
The reason why I asked this is because I am looking for a PCB mount SP3T switch for choosing between Triode, UL and penthode mode by connecting the screen to plate, UL tape of OPT and to +350V respectively. The best I found is this one:
https://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=244579932&uq=636469000785895511
It is not easy to find a switch that can withstand high voltage. This one is rated 125V for AC and DC. You think this is good enough? All the voltage is within 125VDC, the arm is plastic, so the whole switch can be float up.
That's what I think, but even if you switch when the amp is on, it's within 125V......from 425 to 350V is only 75V.
You click the link, you can get the datasheet. also, if you scroll down in the digikey page, they tell you..
Strange!!On my end that link doesn't bring up the product, maybe it's stored on your computer somehow.
I think a standard switch will work for a DIY amp though.
Yes, all 4 contacts are between 425 and 350V, but the shaft is plastic, if I don't put any ground around the switch, the switch only see 75V. All it shouldn't hurt me if I touch the shaft.The thing that is not within 125V is the switch operator, Alan.
That might be the case. The point is that the 125V switch rating is not the relevant spec for that.All it shouldn't hurt me if I touch the shaft.
Yes, all 4 contacts are between 425 and 350V, but the shaft is plastic, if I don't put any ground around the switch, the switch only see 75V. All it shouldn't hurt me if I touch the shaft.
I don't know what you are talking about. This is page 2, it specified "break before make"Did you see in the datasheet on page 2 where it says, "No common terminal is present. Switching function is provided by movable contacts shorting adjacent pairs of stationary contacts."
If I understand that correctly, then you can't do what you want using just 3 positions.