Reducing voltage on Lionel saw mill to get right operating speed

You could just add a resistor in line with the sawmill.   You can use a calculator such as this one:
http://www.gtsparkplugs.com/Dr...g_Resistor_Calc.html

To determine the value of the resistor.  Is your accessory transformer AC or DC?

Will the accessory run on DC?

Would it be difficult to run one more wire to the accessory with a lower A-C voltage on it?

I know this may not be the way you operate your accessories, but what about adjusting the voltage on the transformer that powers them.  Each of Lionel's accessories seems to want a little bit different voltage.  If you have a layout full of them, and only run one at a time, like the sawmill, coal loader, etc., you can vary the amount of power it receives when you run it.

The last operating accessory layout I had, included many trackside accessories.  It seemed like each time I wanted to run the same accessory, it wanted a slightly different voltage.

Exactly my point, in asking if there would be a problem running one more wire under the table.

I found one of my accessory transformers (1033) with the track voltage not being used, so I ran a dedicated wire from the transformer to the sawmill. Then I set the voltage to run the logs through the sawmill at the slowest speed that would operate without stalling. (10.5VAC) 

Works well and didn't take long to run the extra pair of wires.

Thanks for your inputs:

All my post war accessories have there own transformer

clem k posted:

All my post war accessories have there own transformer

I'm happy for them.....LOL

If one doesn't have the luxury of a spare adjustable accessory xfmr, Dale H describes the diode-dropping method here:

http://jcstudiosinc.com/Voltage-Dropper-Diodes

Each pair of diodes drops the AC voltage by 0.6V.  In the OP's example, 13.8VAC must be dropped by 2.3V to 11.5VAC.  So 4 pairs will drop 2.4V which ought to be close enough.  You can get 8 suitable diodes for less than $1 on eBay (free shipping from Asia).

This is a great thread as I have been wanting to reduce power on certain accessories using one transformer.  But I really don't know anything about electronics, so can someone draw up exactly how I would take the Diodes and reduce the voltage of the power lead going to an accessory.   Take the sawmill example.   Starting from the power wire from the transformer that goes to the sawmill, exactly how would I solder in these diodes and their orientation to drop it say 3 volts.  I'm assuming these diodes would be in between the transformer and the accessory on the power side.

Sean, take a look at this thread which probably has too much information but does include photos:

https://ogrforum.com/t...-a-single-accessory?

Yes, the string-of-diodes would drop in between the transformer and the accessory.

Note that diodes have a current-carrying parameter specified in Amps.  Many accessories requires less than 1 Amp, very few (if any) require more than 3 Amps.  So you select a diode Amp rating that, say, is double what you expect to use.  The higher the diode Amp rating, the larger the diode and fatter the wire-leads which can make it more tedious to assemble.

However, what may not be obvious is the diode-string can drive multiple accessories with each accessory "tapping" into the string at its preferred voltage...or you may have multiple accessories running off a single reduced voltage tap.  In such a case the diodes must be able to carry the combined current so that's why, in the absence of further information, 3 Amp diodes is a good starting point.