TPC VOLTAGE LOSS

from the TPC manual;

Maximum input voltage: 9 to 30 volts (AC) at 50 or 60 Hz

COMM input signal: +/- 12 volts

Maximum output current:

15 amps at 20 volts or 300 watts (TPC 300)

20 amps at 20 volts or 400 watts (TPC 400)

 

your TPC might need to be re-set to permit maxumn output.

http://www.lionel.com/media/se...ents/71-4189-250.pdf

 

I've done the reset too, still I have the voltage loss, I may take the tmc's out of the circuit to get more voltage on the track.

From what I understand that voltage loss is normal. Since the TPCs modify the waveform to a chopped sine wave the amps are really what you need. What kind of power is going into the TPCs?

The loss you're experiencing is normal circuit loss and is released in heat. To get more out you have to put more in. You're saying you get 17.1 volts out. I would think that would be plenty to run any train at any speed below fly off the track. If your engines aren't running fast enough I would be looking into loss from the TPC to the track wiring. Long runs of 16 or 18 gauge wire would cause large voltage drops by the time it reaches the engine.

Ron

I'm running 12 gage stranded for bussing and 16 gage feeders. My main line is 150' with 14 power drops, very low power loss. I would think that the power house put out a shark tooth sinewave like the tpc's do.

Your wiring sounds fine. The powerhouse transformers put out a pure sine wave just like any post war transformer. They just aren't adjustable. The output of the TPC is a shark tooth waveform similar to the ZW-C and the powermaster.

Ron

If you are running tmcc exclusively then the tmcc lockon would be a better choice than an adjustable tpc. The lockon simply connects the 180 watt brick to the track with a relay, and still provides a fast electronic breaker in case of a short. While the tmcc signals are not available to control the voltage, the emergency stop signal will still be received by the engines and stop them if necessary.

"If it ain't broke, don't fix it".  I'm with Ron, 17v is plenty,if your still getting 17v at the track your fine.One more volt when your already up to 17 will make no difference. FWIW for an accurate reading you need a load on the transfomer/TPC, run a loco and doublecheck your output. I run my bricks through a TPC unit dialed back to 15 or 16 to help lengthen the life of passenger car bulbs and eliminate arcing during a derailment. I know folks who run legacy/tmcc stuff as low as 14v with no operational  problems. 

 

Sounds pretty normal to me as the electrical guroos of this forum explained to me. I run 4 180watt bricks into a ZW-C. Each brick outputs 18V into the ZW. But when I measure the output at the ZW-C, it's just a tad over 17V. A little loss passing through the boards and such. Shouldn't affect performance at all, it doesn't on our layout with 2.5% grades and long lighted passenger trains.

Thanks for the info. I am new at ln model railroading I don't know what is normal .