10 Amp miniature toggle switches

Consider some relays operated by the switches to achieve the 10A (or more) rating.  Finding those switches with 10A capability is probably going to be difficult.  The contacts just can't be made large enough in those tiny switch bodies for high currents.

http://www.radioshack.com/prod...sp?productId=2062486

Radio Shack claims:

1 x SPDT center off high-current mini toggle switch

Rated 10 amps at 125VAC. Includes green, red, yellow and white handle covers. On/off switch requires 1/4" mounting hole.

One problem with parallel contacts on DP switches.  The contacts don't necessarily make or break at exactly the same time.  The current rating of a switch is primarily determined by the make and break (especially break) characteristics of the contacts.  So, if they don't break at the same time, you get the full load across one set of contacts for a brief period with the resultant arc that damages them.

Standard toggle switch that I have used from a local electrical supply.  Heavy switch with screw terminals.
NSI industries  20amp rated at 125 VAC, 10 amp rated at 277 volt.
Pictured is: 78230TS Double pole double throw.
78210TS On Off Single pole.  They are available in momentary also.

Works well for my turntable control with a cross over added.

John's recommendation to use relays always intrigued me, but for a long time I could not see how to do it when using DCS because of the need to go through the TIU.  As I get more familiar with the passive mode of DCS, I can see how this will benefit me.

My TIU will be near the transformers for my mainlines.  I initially had my transformer for the turntable located in the same place, with power going through the TIU then 25 feet to a terminal block that distributed power to the turntable tracks through switches along the side of the layout.  I have now moved the transformer to underneath the turntable and will be using relays off the terminal block to control power to the track.  The switches for the relays will be along the edge of the layout (I'm looking at doing this with a rotary switch if I can find one that will work).  Wires from one of the TIU's outputs to the input side of the terminal block will carry the DCS signal.  This results in much shorter wire runs for track power.  Unfortunately its more complicated but I have time to do it.

Now, if I can just fine some 15-20 amp relays for the mainline I can do something similar there.

Ron

General purpose relays are available from Grainger Supply.  The only issue related to model trains is voltage/coil voltage.  If 18 volt AC is your choice of control, it may be difficult.  12 volt AC is readily available, as is 12 volt DC, then voltage jumps to 24 VAC or DC.  Here is a standard relay, 12 VAC coil, that requires a mounting base.

Click on the underlined phrase to link. Note that these relays have higher voltage and amperage ratings for general electrical control work, one step-up from somewhat fragile electronic work.  IMO.   Best wishes with your project,   Mike CT   The last relay I purchased, was used on one of the Fort Pitt High Railer's animation modules. Some animation equipment was supplied that operated at 110 volts.  I did not want to expose the general public to push buttons that operated at 110 volts.  I added the relay to reduce control/push button voltage to 12 DC.  This relay fit in a standard 4" X 4" X 2 1/8" deep electrical box.  Relay is in the silver metal box bottom of picture.

The beauty of relay control is you don't have to supply the coils with the same voltage as the contacts are switching.  Since 12V DC relays are very common, just use those with the contact rating of your choice, and you're all set.  One small 12VDC power supply runs the whole panel.

Dale,

I like your schematic for the push buttons; it does provide much more flexibility than a rotary switch.  Can banks of 10-15 buttons with this functionality be found already made by a manufacturer? I would prefer to buy these already made, two 10+ button circuits for 10 amp and one 4 button circuit for 15+ amp.  If not, I can build these, just not what I like to do.

Ron

Almost always the coil ratings are totally independent of the contact ratings, so that's certainly a true statement.  I don't know that I can actually find a relay that has contact ratings the same as the coil voltage...

The same relay I referenced above can be ordered with a 240 volt coil.   Coil voltage and contact rating the same.  Not a model railroad application. 

Mike, I guess my basic point is that the contact rating has no direct connection to the coil rating.  You'll find 99 out of ever 100 relays with a different coil voltage than the contact rating.

Dale,

Thanks for the response.  I guess I'll order the parts and get out the Weller.  I have a couple of 12V transformers from Scott's Odds and Ends.  Do you have relays that are 12V and can handle 15.4 amps switched on/off?  The 15.4 amps is the setting on my PSX-AC circuit breakers.  Thanks.

Ron

Dale,

Thanks for you continued patience with me and my lack of electrical knowledge.  I forgot the Scott's transformers were AC.  I do have an MTH Z-DC1 transformer that goes from 0 to 17VDC, although it is only 19W max.  I think this would work.  I need to re-draw your diagrams myself so I can follow how it should be put together.

However, I'm thinking of going back to using Lionel ASCs to control power to the roundhouse tracks.  The ASC seems to be a simpler solution although a bit more cumbersome to use through the CAB than using switches (plus I have lots of ASCs).  This leaves me with the 4 mainline blocks running up to 15A that I want to turn on/off.

Going back to the original poster's (John) thoughts may be something to consider since my transformer to mainline run is relatively short and near the table edge.  All the great info from all of you has given me something to think about.

Ron