Toggle switch question

I use 6amp toggles for all the sidings and engine tracks to turn track power on and off. Never had an issue. 

Ratings for switches don't scale linearly since there are many factors to consider. VAC vs VDC and the type of load that is being controlled by the switch. So if you are trying to play it safe, just stick with the rating given on the switch. 

Generally speaking,  toggle switches will handle higher amounts of current than what they are rated for, it just reduces their life. As Laidoffsick mentions above, for what we use them for and since we are not dealing with mission critical situations here, you likely won't have a problem.

But for safety reasons, always have adequate fuse protection on any power transformer that feeds the layout. That's the most critical feature to keep things safe. 

Most retail toggle switches (like those at Home Depot, Lowes, etc) have ratings of 10 amps and higher. Unless using the 6 amp switches is critical for budget reasons, I would search out higher rated switches for your track power toggles, and maybe use the lighter switches for building lighting, signal circuits, etc where the loads will be less. As was said, don't omit suitable fuses in any case.

Rod

While the science could get very complex in showing that you might get some added current capability at lower voltages, for practical purposes the answer is NO running at lower voltage will not improve the current rating.  

The voltage rating will reflect the distance between the switch contacts in the off position, grater distance prevents arcing at high voltage.  The current rating will describe the amount of surface area that makes contact when the switch is closed/on.  More contact area allows more current.  

You can usually get away with a bit in the opposite direction, however, say running 18 volts through a switch or relay rated for 12 volts, with less current than the rating.  Though you may shorten the life of the switch as arching slowly eats away at the contacts.    

If you want the best bang for your buck for on/off switches, it's hard to beat standard light switches, rated at 15 amps and 120VAC or more, and costing about 50 cents.  If the space is at a premium, however, it may be worthwhile to use the lower current toggle switches to trigger relays, which in turn control the high current loads.    

JGL

I have found that using the automotive switches are a better fit for model train applications. Usually higher amperages and no compromises for high voltages. The ones I use also have an LED in them that are rated at 12 vdc and it turns out that 18 vac can be used directly since the LED only conducts half cycles. I also put a 1N4003 in series with the light so that the LED is protected against the reverse cycle peak voltage. The LED won't suffer immediately from the reverse cycle, but eventually will fail from the reverse peak voltage.

Thanks for the information. I will use the DPDT toggles that are rated at 10 amps at 125 VAC. I have so many buildings in my basement I am nearing 6 amps per Z-4000 throttle handle as it is, and have more to hook up.

BTW: since I only need one side of the DPDT toggles how do I hook up the wires to them? The back of the toggle has 6 points to connect wires to (3 pairs of points) and the toggle position is middle = off and up and down = on. Do I solder the transformer wires to the middle pair (off) and then solder the terminal block to either the upper or lower "on"?

Yes. Paralleling the contacts is fine. But you might want to use the unused side for an on/off light.

Paul, 

If the 6 amp switches you have are set up the same way, DPDT, with six connections, you can double up the poles on the switch to make them effectively 12 Amp switches.  It's not optimal for a mission critical application, but to turn lights on and off it should work fine.  Here you would connect each row of two terminals together.  

As to your latest question, think of each row of three connections as a separate switch. Typically the middle point would be the 'input' with the two outside connections being turned on when the switch is thrown in the direction opposite of the terminal location on the switch body.  

For a lighting application, however, you might consider reversing the normal set up, and instead connect the lights to the middle connection and the input supply to one of the outside connections.  This would allow you to connect a second power supply to the other connection, on a center-off switch, allowing for two different voltages ( and thus two different brightness levels) that could be selected from the switch.  

JGL

Paul Kallus posted:

Thanks for the information. I will use the DPDT toggles that are rated at 10 amps at 125 VAC. I have so many buildings in my basement I am nearing 6 amps per Z-4000 throttle handle as it is, and have more to hook up.

BTW: since I only need one side of the DPDT toggles how do I hook up the wires to them? The back of the toggle has 6 points to connect wires to (3 pairs of points) and the toggle position is middle = off and up and down = on. Do I solder the transformer wires to the middle pair (off) and then solder the terminal block to either the upper or lower "on"?

Paul:

15 amp SPST switches are out there but expensive - http://www.allelectronics.com/...toggle-switch/1.html

Joe

Thanks everyone for the details on toggles.

I must have close to 35 toggles left over from last layout - some still in the package, and I love to reuse things. To date, I've re-used all my last layout's wire and some scenery - saving big money.