# Can I use this XFMR for NCE?



## JackM (Jul 29, 2008)

The heavier the transformer, the more cautious I am. This one calls for some serious caution - I think.

I've decided that I want to break up my layout (about 500 ft. of SV SS track) into two sections, especially since I may be adding more track next year. I may have gotten a bargain at the local hamfest on Saturday - only five bucks! (For the first time around, I used the $100 transformer NCE recommends.)

This is a Hammond, from Guelph, Ont. Type 11 (whatever that means), 60 Hz, 120 V. VA=348, Secondary: 29 V. Two wires in and two wires out, so it's not a center tap. I don't recall how to apply P=IE from this information. (348 divided by 29?)

So the questions -
1 - Can I get 10 amp at 16-20 volts out of this guy?
2 - Is it worth the effort?

It only cost me five bucks. I can always spray paint it orange and have a nice door stop.

JackM


----------



## JPCaputo (Jul 26, 2009)

You are right with the P=IE. It should handle 12 Amps without problem. 

When rectified to DC, there is about a 1.4x increase in voltage, making it to be about 45 VDC unregulated. 

You can make a linear power supply out of it without much problem. I would suggest to duplicate an ASTRON power supply schematic. It is a little complicated, but it has protection built in that will cut the output incase something goes in the power supply. 

For probably $20 in parts or less you can make a respectable linear power supply. Check out all electronics or other electronic surplus store for good prices on parts.


----------



## Greg Elmassian (Jan 3, 2008)

Caution, VA is not rated at EVERY volt and amp combination... Often a manufacturer rates the VA of a train power supply at somthing less than full output voltage or current. (Buy a cheap MRC power pack and prove this to yourself). 

P = EI does not apply in AC, only DC... power in watts comes from an equation if you have sinusoidal AC (which you have) 

Now I think 29 volts is too high to put into the NCE system, call them to be sure if you don't find the AC max input explicitly in the manual, the max DC input voltage is 27 dc for sure, and I forget the ac input limit.. 

If it is rated 29v in use, unloaded it's probably much higher. 

Bottom line, if you are using an unregulated supply, you have to be very careful not to exceed the input ratings. Get a Meanwell 27 volt 11 amp supply, regulated DC switching power supply. 

Then you will be extracting all you can get from the NCE... 

Regards, Greg


----------



## JackM (Jul 29, 2008)

I have the schematic from my old Pyramid power supply but it wants a CT transformer. Anyway, I now recall what I learned when I first bought the NCE system a few years ago and decided to NOT do it myself. Same situation, same decision. 

Door stop it is! 

JackM


----------



## Greg Elmassian (Jan 3, 2008)

You can get the meanwell for around $60, now you have a regulated power supply and the voltage won't vary under load and it will be more power efficient and you will have a power supply that will have the ability to extract all the potential of the NCE system. 

Wise choice. 

Greg


----------

