Controlling one Tortoise machine with 2 toggle switches

[faithie999]

I have a few Tortoises that I would like to control from 2 locations.  I am using DPDT switches for the normal installation.  Can I wire 2 switches in series, like using 2 3-way switches for a ceiling light, to control the Tortoise?  I know I would lose the "UP/DOWN" orientation of the DPDT switches to correspond to the position of the turnout.

thanks

Ken

[Alan]

Yes, as long as the switches are in series i.e. one switch feeds the second switch which then feeds the Tortoise.

[faithie999]

great!

if I were to control a couple of turnouts with an AM-1 (and I know it's a pain to switch from loco screen to AM-1 screen and back), I see in the AM-1 instructions the Tortoise motor in put shouldn't exceed 12v.  how would I handle that with the 15v MeanWell power supply?  dropping resistor on the output of the AM-1?  buck converter?  don't worry about it?

thanks
ken

[Alan]

Your thinking is correct. A dropping resistor will do the trick.

Place a 220 ohm 1/2 watt resistor in series with the Tortoise. This supplies the Tortoise with 11.6 volts at stall from a 15 volt supply.

Tortoises operate just fine and a lot less noisy at lower voltages. Feel free to increase the resistor value up to a maximum of around 1000 ohms (6.5v at Tortoise). Tortoises have less throw power at lower voltages. The least voltage required will be dictated by how freely your point rails move.

[faithie999]

Thanks!

Ken

[Alan]

As a follow-up comment...

Ken, you are beginning to experience the reason why I use multiple power supplies and corresponding buses. One for trains (org/wht), one for accessories (grn/wht), one for solid state electronics (blu/wht). For a variety of reasons there are certain low voltage norms in the world that manufacturers have coalesced around. 1.5v, 3v, 5v, 6v, 9v, 12v. Missing from that list is 15v. Much like your Tortoise adventure, with 12v being overwhelming dominant, running the whole layout on the 15v train supply will necessitate a lot of 'voltage adjustments' as your layout grows in complexity. Consider what happens should you need to operate a 12v device at much more amperage than a lowly Tortoise. The resistor you will need can be correctly called a toaster!

Providing a separate 12v buss makes life so much simpler.

[faithie999]

Alan--thanks for the message.  actually I learned about multiple busses from one of your blogs.  I have #12 wire under the table for 15v and #14 under the table for 12v.  I have plenty of room for a 3rd bus if I need it.

and then this morning I learned that you can place a bi-color LED in series with either wire #1 or #8 on the Tortoise.  for now, that will be a cheap way ($6 for a pack of 25 on eBay) to note turnout position.  for now I'll just push them up from underneath the table.  I am using 1/2" fiberboard for the top layer so I can drill a hole just smaller than the LED and snug them into the holes.  later I'll "do it right" with prototypical-appropriate signal lights.

[Alan]

Good on ya.