SPST/DPST Switch Question

I use Calterm rocker switches that are from the auto section of the hardware store. They mount in a round hole and have led pilot lights. You connect the power, the A terminal of the transformer, to the "supply" terminal. The block center rail to the "load" terminal. And the "earth" terminals all connected together to a single diode pointed toward and connected to the U terminal of the transformer. The diode protects the led from reverse voltage and the leds only see half wave of up to 18vac which averages less than 10volts dc.

Why two feeds to an Isolated track?  Double Pole has capability to switch two feeds together.  G

GGG - I have 2 separate sections of isolated track that I need to cut off power to in one of my reverse loops.  I thought that a DPST switch would do the trick - yes?

Paul

Yes, but they both go off together when you throw the switch.  If that is what you need, it will work.  G

I am not sure what you mean by a "set" of feeder wires. There is a center rail wire power and an outside rail power wire (I like to think of this one as a return wire or com). Anyway, to turn off a block, you just have to cut power to the one wire to the center rail. If the block has two wires feeding the center rail at different points in the block, you will have to cut power to both of them and a dpst switch is required.

cjack/GGG - I guess I should have said "pair" instead of set.  On one of my reverse loops the track is divided into 2 isolated tracks (by isolated I mean each has their own pair of feeder wires and they are isolated with a insulating fiber pin in the center rail).  At times I will need to cut the power off to both isolated tracks to park engines etc.  I would like to throw one switch to cut power off to both tracks - it sounds like you're saying a DPST switch would do the trick - correct??

Also, I need to know what amperage should the toggles be rated at.  Any help on that would be greatly appreciated.

Thanx,

Paul

That's correct. DPST will break two independent circuits. I would look for at least 10 AC amps. They will be rated like 10 Amp 125 VAC or 250 VAC. Mini toggle switches are usually only 6 Amp switches. The auto switches I mentioned earlier are only SPST, one circuit.

Do a search for "dpst toggle switches" on the bay in "electrical and test equipment" to see many types. Look for ones that just say ON-OFF and do not choose "center off" or "momentary". The ones with screw terminals might be handy.