One post, two questions - switch ratings and battery fitment

[Bimmerboy]

Rather than start two seperate threads for a couple of simple (hopefully) questions, I'll stick both in this one.

First, does anyone know exactly how a switch rerates to varying voltages and currents? For example, will a switch rated for 1A @ 20V rerate to 2A @ 10V?

Second, does anyone know if AW's R123A's will fit in a SF 6P?

Thanks in advance!

 

[mdocod]

1: I don't think there is any such thing as a universal switch-rerating formula. Different types of switches can handle different conditions (high voltage, or high current) better than others. If I build a switch designed to break a 120V 1A connection, it may do it just fine, but at 12V 10A, it might melt.

2. AWs R123s should fit the 6P just fine, just make sure you use a compatible lamp with the voltage change You might have to remove the sticker on the cells.

 

[Anglepoise]

First, does anyone know exactly how a switch rerates to varying voltages and currents? For example, will a switch rated for 1A @ 20V rerate to 2A @ 10V?

Its the other way round. The higher the voltage, the switch can carry more current. So a switch will be rated, example 10 amps @ 120 volt and 20 amps
@ 240 volt. Same switch ,yet different current handling dependent on voltage.

( Later edit.....There seems to be a variation with switches. Some seem to be rated to carry more current with higher voltage, others the opposite.....so please disregard my earlier answer above. )

 

[Bimmerboy]

Thanks for the responses, guys.

mdo - I think you're right. Getting the feeling that it's more about simply current than a ratio of V to I, but hopefully not completely. I do see some OEM re-rating of switches, but will have to investigate this more.

Angle - That seems contrary to what I would assume, but then again, I really don't know.

Time to hit an electronics forum! Will report back.

 

[Anglepoise]

Thanks for the responses, guys.


Angle - That seems contrary to what I would assume, but then again, I really don't know.

You got me re thinking this and I checked a few switches in my possession and there does not seem to be any exact pattern. One switch I have states
in AC volts....6 amp at 125 volt, 3 amp at 250 volt. Others are the other way around so please disregard my post and I will edit it.

 

[Norm]

I fairly sure that DC is harder on switches than AC so a switch rated a 10 Amps AC may not handle 10Amps DC.
Found this here http://www.kpsec.freeuk.com/components/switch.htm
Switch contacts are rated with a maximum voltage and current, and there may be different ratings for AC and DC. The AC values are higher because the current falls to zero many times each second and an arc is less likely to form across the switch contacts.