Hello,

Just a quick question about ratings on packaging. I am trying to find a switch for a project of mine.

The packaging states .5A at 200VDC, does this mean at lower Voltages it will be able to handle higher currents?

Thanks.

 

yes and no.

due to the size and composition of the contacts, there is a limit on how far you can lower voltage and raise current.

The I(sq)R losses appear as heat in the metal contact, and due to physical constraints such as size and surface area, an increase in current will produce a greater rise in temperature when passing the larger current. You will MELT the contacts if you raise the current too high.

 

Ah gotcha thank you!

 

No, voltage rating has nothing to do with the current that can flow through the switch.

 

One more question,

I bought a DPDT switch that seems to be rated for VAC, and the diagram for wiring from what I have found looks like this where + signs means there connected.

Switch up

1 2
+ +
3 4

5 6

Switch down

1 2

3 4
++
5 6

Can I use it to just run a rectified DC voltage through it like this with just one wire?

Switch up

1 2
+
3 4

5 6

Switch down

1 2

3 4
+
5 6
Thanks

 

I don't understand your 'number switch' stuff, but, A switch doesn't care if its AC or DC anymore than a copper wire cares what kind of voltage it carries.

A switch is basically a piece of wire that can be broken and reconnected multiple times.

 

Here is the link to the switch I got, the numbers are the contacts on the switch.

http://www.radioshack.com/product/index.jsp?productId=2062537#inTheBox

and I attached the picture of the diagram of a DPDT Switch.

Yes, That is why I am confused why its rated as VAC?

Thanks

 

I don't understand your 'number switch' stuff, but, A switch doesn't care if its AC or DC anymore than a copper wire cares what kind of voltage it carries.

A switch is basically a piece of wire that can be broken and reconnected multiple times.

I respectfully disagree. breaking direct current can be much harder on a switch than breaking alternating current.

 

So does anyone know if I can hook it up with just one of the terminals being used instead of having both hooked up? as in the diagram above i posted with numbers?

Thank You.

 

Yes

The two 'poles' refered to by the DPDT label(Double Pole Double Throw) means it has two seperate poles, or two sets of contacts.

You do not have to use both sets of contacts for the switch to work.

I respectfully disagree. breaking direct current can be much harder on a switch than breaking alternating current.

I didn't want to get to deep into the 'physics' of switches and arcing at the contacts. It seems just knowing if he can use the switch was taxing his understanding already, but I agree Stantor. Dc does have a greater tendency to draw an arc and do damage to the contact surfaces.