convert VAC to DC?

Hi.

This is just because I'm interested really, not because I will get close to these ratings...

I have a selection of switches, which are all rated

6A 125VAC
3A 250VAC

Click to expand...

The ammount of current it can take varies with the voltage, thats fair enough, but what if my voltage is DC? Does it make any difference? Do I need to comvert it to RMS or something?

Thanks

Tim

grrr_arrghh said:

Hi.

This is just because I'm interested really, not because I will get close to these ratings...

I have a selection of switches, which are all rated

6A 125VAC
3A 250VAC

Click to expand...

The ammount of current it can take varies with the voltage, thats fair enough, but what if my voltage is DC? Does it make any difference? Do I need to comvert it to RMS or something?

Click to expand...

The DC current rating is usually considerably less than the AC rating.

The reason for this is quite simple, when the switch opens an arc is formed across the contacts - with AC the voltage falls to zero every 10mS (at 50Hz), so the arc can't last longer than that. With DC it doesn't fall to zero, so the arc lasts considerably longer - so the contacts are generally downrated for DC use.

Probably your 6A 125VAC would downrate to 4A at 24VDC. It 'should' be given in the specifications of the switch (but isn't always).

so there's no direct conversion formula?

(they could handle a couple of amps at 12v no probs then, which is all they are likely to have to...)

Thanks


Tim

grrr_arrghh said:

(they could handle a couple of amps at 12v no probs then, which is all they are likely to have to...)

Click to expand...

Yes, that should be fine!.

cheers mate!