fine tuning accessory voltage

You can drop voltage with diodes ,described here

http://www.jcstudiosinc.com/BlogShowThread?id=413

Dale H

In general, you are better off using individual supplies for each accessory, find the optimization point and leave it there. Same goes for fixed voltages to switches and remote control tracks.

Sounds too complex till you buy a few Type V or Type Z Lionel transformers. They are compact and each gives you 4 separate controllable outputs. Been doing this for years. Every accessory on the layout, switches and RCS section work flawlessly.

What I do and find useful is to determine an optimum voltage for each accessory that gives me the results that I want for that accessory.  I record that.

Then I group together those that like roughly the same voltage and bundle those together using the same output post on my V transformer, set to the correct voltage (as determined by a multi-meter reading).  This gives me 4 groupings with 4 possible voltage settings, which is plenty.

From each output '+' post on the 'V', I run a 14 gauge wire to a dedicated barrier strip for that post.  I then distribute to each accessory in that post's accessory grouping from there.  Thus, 4 '+' wires from the 'V' to the 4 barrier strips.

I run a single 14 gauge '-' wire to a separate barrier strip and distribute ground wires from there.  I only use one '-' output post and one barrier strip overall for this.

- walt

You can frequently find the little set transformers for peanuts or even free, most of them have plenty of power for a single accessory.

Thanks for the tips.  I have discovered that I have an accessory voltage controller.

I have downloaded the instructions for it , but have basic questions.  Am I correct that I can program precise voltages for as many as nine accessories and then power up any one of the nine at its programmed voltage.  Is that true?

John,

You are right about that, just does not make for a classy setup if you have a bunch of different voltage needs. Best set it all up one time in a hidden place and forget it.

Well, you can hide all the little transformers too.

okay, I recall the AVC was expensive, and I never used it because I thought it was a single output transformer with a variable voltage output. Big deal!!  Well, it appears that it will do a lot more than that.  I plan to run a new bus around the layout. The bus will be powered by the AVC which will get its' power from a dedicated transformer.  Each accessory to be controlled will have a tap off from the avc bus. The voltage for that aaceeory will be fine tuned thru the CABTo run that accessory, the avc( which will be designated track4) will be called up and the programmed voltage for that accessory will be turned on by punching up AUX1 and the number between 0and9 programmed into the avc for that voltage.

   Only the hot side of the accessory will be tied to the AVC.  The common side will run from my common bus, to an on /off switch thence to the common pole on the accessory. The common on the AVC will also be tied to the common bus.

I never used this, but it appears you could only run one at a time, that would be a limitation you might not like.

Taylorra!

You have 4 simple answers to an obviously simple question? Dale, Walt, John & Self.

What is it that we are missing in understanding the problem?

For John:

  I am about to call Lionel for clarification.  I think you are right and wrong about one accessory at a time.  As I understand it, I could only specify one of ten programmed voltages at a time, but that voltage, programmed for exact operation of one accessory, would be available to all connected accessories.  The challenge would be to program a specific voltage for my touchiest accessory, and identify any other accessories which work well at that voltage.

  The problem that started this discussion is that I have two transfer tables with extensions physically connected together  and wired to a single controller to operate in unison.  The problem is that, although the tables are both most recent production, 1 runs a little faster than the other which causes the tables to lose alignment.  The solutions offered are all good, but since I paid something like $125

for the AVC, I am going to try to make it solve my problem.  I am saving all of the suggestions for reference if I need them.   THANKS TO ALL!!!

If your accessories use less than 2 amps, and can tolerate DC, then this might work.

http://www.ebay.com/itm/LM2596...ule-3A-/331040137192

It is continuously adjustable over a wide range of input and output voltages. For under 4 bucks, and no shipping, I'd check it out.

There are other similar ones on Ebay. Just search for "DC adjustable converter"

Here's one that will deliver 12 amps.

http://www.ebay.com/itm/DC-DC-...-2-35V-/200972882940

Well, you're right that if you had two accessories that needed the same voltage that you could run them both.  OTOH, that kinda' defeats the primary idea of having a unique voltage for each accessory.  In your specific example of the transfer table, it appears you need two different voltages, so you can't do that at the same time with the AVC.