Powering the Peco PL35 CDU?

[A Postpischil]

I've decided to use Peco PL-10 machines to throw the turnouts on the exhibition layout I'm building. I've got them wired and connected to Peco's PL-35 CDU. The PL-35 instructions say to power with either 16VAC or 12VDC. I'd like to know if the CDU will work with 13.8VDC...or will I fry it?

That's the output for the adapter (PS314) that powers the Digitrax Zephyr I'll be using. As an FYI, I emailed Peco with that question and the response I got was that they don't recommend using DCC track power (which I know and wasn't the question I asked).

I'm hoping to avoid multiple power supplies as the Digitrax PS314 provides more than enough power for 1-2 engines and throwing turnouts. Thoughts?

Update: I attempted to use the 13.8VDC power and the CDU didn't work. I had ordered a 16VAC power supply just in case and that worked. So I'm stuck having to use 2 power supplies for the layout. :-(

[B.Meldon]

I would stick to the manufactures guidelines. However, the PL-35 is an expensive CDU! The last one I purchased was under £10 from e-bay and was rated up to 20v AC or DC input! This is part of my automated standard gauge layout, it switches two points at once and must have done this thousands of times now.

[Hugh Norwood]

I should think it would be fine.

[Graeme Dunbar]

Yes, the supply should be fine. The output of a typical small 16 Vac transformer or the unsmoothed 12 Vdc derived from it varies quite widely depending on make/model and the amount of load it is under. Small transformers are notorious for having poor voltage regulation.

The power supply you have is a 'modern' switched mode supply. Its output is much more closely regulated and well within the range you are likely to get from an older transformer.

[B.Meldon]

I should add a word of caution that cutting the wire on the PS314 and using it to power any other devices would constitute 'customer modifications outside the scope of instructions' and may well void the Digitrax warranty. Also the PS314 delivers up to 3.8amps and I do not know what if any short circuit protection this power supply has so I would strongly recommend some other form of short circuit protection if you use it to power your CDU. Unintentional shorts in the supply may also have an adverse effect on the Digitrax Zephyr, that again may not be covered by warranty.

[Hugh Norwood]

That's a point... if you're using the PS314 to power your DCC box, how are you thinking of getting the 13.8V out to power your CDU? Does the PS314 have two DC outlets?

[A Postpischil]

I should add a word of caution that cutting the wire on the PS314 and using it to power any other devices would constitute 'customer modifications outside the scope of instructions' and may well void the Digitrax warranty. Also the PS314 delivers up to 3.8amps and I do not know what if any short circuit protection this power supply has so I would strongly recommend some other form of short circuit protection if you use it to power your CDU. Unintentional shorts in the supply may also have an adverse effect on the Digitrax Zephyr, that again may not be covered by warranty.

The unit is out of warranty, so that's not an issue. I don't plan on cutting the cord, so that's not an issue.

As far as I know, the PS314 doesn't have any short circuit protection.

[A Postpischil]

That's a point... if you're using the PS314 to power your DCC box, how are you thinking of getting the 13.8V out to power your CDU? Does the PS314 have two DC outlets?

The PS314 has a 5.5mm barrel plug on the end, so using a splitter to double the number of,ber of plugs. Then one goes to the Zephyr and one goes to a jack for the PL-35.

[Terry Mowles]

The PS314 is a bog standard switchmode powerpack (wallwart in the US), so any overload/short circuit would (hopefully) shut it down.

I would suggest adding some independent short circuit protection rather than relying on the power pack to shutdown in the event of a fault.

[A Postpischil]

The PS314 is a bog standard switchmode powerpack (wallwart in the US), so any overload/short circuit would (hopefully) shut it down.

I would suggest adding some independent short circuit protection rather than relying on the power pack to shutdown in the event of a fault.

Ok, thanks.

[Graeme Dunbar]

The PS314 is a bog standard switchmode powerpack (wallwart in the US), so any overload/short circuit would (hopefully) shut it down.

I would suggest adding some independent short circuit protection rather than relying on the power pack to shutdown in the event of a fault.

Hopefully both the DCC command station and Peco CDU will have their own currewnt limitation built in. Short circuit protection is pretty much an essential component of DCC units and I presume (given the price) the CDU is a well-designed unit with current capacitor charging limitation built in - unlike archaic probe and stud or passing contact point control that did effectively short the supply.