He's Back Again: Questions about using the AIU Accessory Ports and Tortoise Switch Machines

Hi all,

I will try to ask these questions as intelligently as possible. I will have a section of the New Munoz Lines that requires a duckunder and it would be a blessing if I could throw my Tortoise switch machines remotely using DCS/AIU. I know the Tortoise machines require 12 volts DC and the AIU outputs AC. So . . . . .

Question #1: If I use the Tortoise machines (Atlas O turnouts) I understand I would need to wire in a "diode" to convert the AC output to 12 v DC? Is that correct? Would I need one diode or must I wire a diode for each Tortoise machine? Could someone do a wiring diagram for me?

I also understand that Circuitron manufactures an AC to DC converter. The Circuitron description of this converter is shown below.

Question #2: Could I wire up the AIU accessory outputs using the Circuitron AC to DC converter and thus avoid the diode? Could one such AC to DC converter be used for all the Tortoise machines?

The CIRCUITRON PS-2 is an AC to DC converter and voltage regulator that will provide a constant 12 volt DC output under varying load conditions and/or variations in input voltage. The PS-2 has a maximum output of 1 amp and a maximum input voltage of 18 volts AC. Note: The PS-2 will achieve maximum output capacity if the input voltage is 14 volts. Higher voltages may result in a reduction in output current capacity. If the supply voltage is less than 14 volts, the output voltage may not stay Regulated and may drop below 12 volts, especially at higher current draws. The PS-2 is constructed on a 3” square printed circuit board, and a section of CIRCUITRON’s Printed Circuit Mounting Track (PCMT) is provided for simple, snap-in mounting.

Many thanks in advance,

Eliot

12/15/1612:35 PM

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clem kOGR Forum Member

Good afternoon Eliot.

Inside each box of Tortoise switch machines, includes the wiring diagrams you need. I can't find mine right now. But I used two Diodes and two Radio Shack terminal strips. This controls all 26 switch machines through 3 AIU's powered by a MTH Z1000 transformer and controller.

Clem

12/15/161:06 PM

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Scrapiron ScherOGR Forum Member

Many thanks, Clem. Please excuse my ignorance. You used two diodes because you need one for each terminal strip? I have two AIU's and two TIU's right now. I plan to use a Z500 MTH pack to power all of those. Do you think that will be sufficient?

Would you be so kind as to help me find the correct diodes to buy at Radio Shack and, if possible, how you wire and mount the diodes for use with the terminal strips? Soooooo many thanks.

Eliot

12/15/161:13 PM

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clem kOGR Forum Member

Give me a bit to see if I can get some photo's

12/15/161:16 PM

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clem kOGR Forum Member

I'm back.........One photo is the directions I used from Tortice and the other is How I wired the diodes in place. It's not pretty but it works. Blue wire is power feed to both terminal strips. notice the little Diodes in the twist connector, one has the silver mark going into connector the other has silver mark away from connector. Been a few years since i bought those diodes at Radio Shack so I have no idea what the rating is on them. "Correction" I have two of these for three AIU's. Look at the #3 directions on the other photo i sent. I struggle with wiring also.

Clem

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12/15/162:11 PM

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stan2004OGR Forum Member

The reason for 2 diodes is to create a positive voltage supply and a negative voltage supply....one diode for positive and one diode for negative. The Tortoise goes one direction with a positive supply and the other direction with a negative supply. You do NOT need the 2 diodes for EACH Tortoise.

Separately from creating positive and negative voltages, if you want to then regulate the positive and negative voltages to a fixed/constant 12V DC you could use the Circuitron PS-2 module. Note that you need two regulator modules - one for positive 12V, one for negative 12V. At $20-25 a piece for the PS-2 that seems somewhat spendy.

It also appears you may need to solder wires to terminal pins on the PS-2 module. If the objective is to minimize wiring, soldering, diodes, etc.. an option is a 12V DC wall-wart adapters. You could use two 12V DC adapters (one for positive 12V DC, one for negative 12V DC). There are handy connector-adapters which provide screw-terminal connections to the voltage. Note that if you use the Z-500 brick method (with or without additional 12V regulation) you might find the connector-adapter useful so as not to cut/splice into the cable; the connector-adapter are about $1 each.