Cobalt turnout motors work with AIU

The recommended way is to use a set of latching relays in line between the AIU and the motor. Have a limit switch open the latch when points are in position or just stall the motor, whichever works best.

If you don't want to do that:

The AIU will pass DC but watch the current, the contacts are not rated for a lot.

Also, just press the button a few times until the switch is fully in place.

The AIU contacts are momentary, they only close for a second or less when you hit the switch. A tortoise type motor needs more time to traverse.

You can use 2 Accessory ports instead as they have a ACT option which holds the relay on as long as you press the button. This uses up your accessory ports fast tho.

 

By the way, I recommend you get Barrys DCS Companion book, pdf or softcover, available thru the MTH website.

It even gives details on how to drive this type motor in several ways from the AIU.

Hi Chris,

 

If you want to control the switches from the DCS remote's "SW" switch menu you can use the methods Russell described.  If you're OK with running your switches from the "ACC" accessory menu you can use this wiring configuration.

Thanks Russ, I looked at the book on amazon today and for 20$ it's a good buy. I thought about the latching relays but not to thrilled about the extra cost.

Dave, thanks for your reply. I would like to use your method to operate the turnouts. I have a dc power supply for them so, Could I just use that instead if the var ac in your diagram and forget the diodes?

I'll let Dave confirm this, but the reason this works the way he has it drawn, is that by using an AC source and the Diodes as shown, he is able to reverse the polarity of the power to the switch motor with just the inexpensive Diodes and a single AIU channel. Using a DC source, would actually make it more complicated (either needing to use additional external relays, or multiple AIU channels).

I think if you have an AC brick, I would stick with this method that Dave has drawn up.

What is a cobalt motor?

Thanks!

No.  As enginEErjon said, the diodes are used to rectify the AC voltage into either a + or - DC voltage relative to ground.  This also cuts the voltage in half, which is why I showed a 12 to 24 VAC power supply.  A 22 VAC power supply, such as a Z-1000 brick, would end up delivering 11 VDC + or - after being rectified through the diodes, which works well with either Cobalt or Tortoise switch machines.

Thanks Guys! Just tested it out and it worked. A few questions, my volt meter read the voltage in both ac / dc mode. I would assume that is because the ground is ac? Also there was a very small amount of vibration on the unit, I believe it was just because of the older transformer I was using. Or is that normal as well?

Chris

Meter worked that way because it's pulsing DC, not a steady current.

Vibration for the same reason, the motor is driving and stopping at 60 Cycles per second.

I wouldn't worry about it.

The Cobalt instructions make reference to the diode method and vibration on p.8: http://www.dccconcepts.com/PDF...alt_instructions.pdf

 

If the vibration or noise is annoying, you could add a 50-cent non-polarized capacitor to smooth out the pulsing half-wave DC.  But I suppose it's better to leave well enough alone.