power off Tortoise switch’s ??

Model Railroader Electronics and DCC
1

another question for the electronics guys.

I’ll have about 25 tortoise point motors on my layout. The layour electronics are all powered by outlets that will be shut off at the end of operations. Since the Tortoise motors will ALL come on when the layout room is turned on will that cause an unacceptable surge on the DCC system? Should I power them from a separate DC Bus?

2

Are you using DCC to drive the Tortoises? They draw very little current, so power-up should not be a problem.

I have a separate supply for my Tortoises, but I run them mostly with panel toggles so I don’t have that problem.

3

Yes. For one thing, if an engine goes into turnout with the switchpoints set the wrong way, the resulting DCC short will kill the Tortoises and the track and you won’t be able to move the switchpoints to correct the short.

4

I currently have 24 tortoises controlled through 3 Digitrax SE8Cs but powered through Digitrax wall warts. Power comes through the wall wart to terminals on the SE8Cs. Sixteen come on all at once when I push the switch on the power strip/surge protector to power up the system. Then I walk around the peninsula and power up the other one plugged directly into a wall outlet. I’ve never had any problems.

Robert

5

I don’t know that I’ve experienced that.

I’ve run through closed switches many times. Digitrax command station and/or booster recognizes the short, beeps, shuts down power to the tracks, and then resets when I manually back the offending engine from the wrong way crossing the switch.

That was the whole point of using a large enough buss wire (Randy’s advice) to make sure the shorting signal gets back to the command station so that the system can respond and handle the problem immediately.

Just my observations over the past couple of years.

Robert

6

Exactly. If one uses a separate power supply, no need for Giant Hand Action to clear the short. Just flip the switch motor toggle and go.

7

Since you already have the circuit breakers for dividing the layout into power districts, if you feed the bus to the Tortoise drivers (I assume you are using something like Swith8’s or Switch-Its with NCE?) from BEFORE the breakers that go to the track, you have the equivalent of a separate power supply. There’s little chance a circuit driving stationary decoders for Tortoises would ever short out.

So you would connect the output of the booster to a bus running around the layout to power the Tortoises, AND to the inputs of your circuit breakers. If a train derails or runs a turnout, the breaker will trip, but power will still be applied to the Tortoises.

The surge of the Tortoises powering up won’t be much, at peak, 25 tortoises will draw less than 1/2 amp. That’s stalled - moving, they actually draw less, so the little bit of movement they will do when powered on won;t be a problem.

–Randy

8

You should absolutely use a separate power supply for the switch machines.

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I have never seen a DCC layout that used the DCC power supply to run the Tortoise switch machines.

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I have never experience any trouble powering on a layout with all the power supplies activated by a single switch, DC or DCC.

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-Kevin

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9

Thanks for the replies.

I don’t have a stitch-it or 8. I was planning on a local control panel with DPDT toggles and LED’s to switch the turnout.

Does the additional electronics make it easier? Better?

Do the Switch-it or 8 work off DC or DCC?

tnanks again.

10

If you are using toggles for the Tortoises, then you NEED a dedicated power supply, Tortoises need DC, they can’t run off the DCC bus.

–Randy

11

Thanks Randy

12

I run almost all my Tortoises from NCE SwitchIts or Switch8s which I power from a dedicated Digitrax DB150. As noted this prevents track shorts from disabling turnouts from being thrown. The Switchit/Switch8s allow me to control turnouts either with local facia toggle buttons, DCC throttles, or JMRI on the central computer.