DCS Variable Out not working

You need to set up and use TIU Tracks, one for each of the variable channels. Assuming that your TIU is #1, there should already be a pair of TIU Tracks set up in the TIU.

After you turn on power to the variable channel (and fixed #1 as because of the jumpers you have in place, do the following:

• Press TR to view the Track List
• Highlight the track for variable channel #1
• Press the thumbwheel
• You will now see a display showing zero voltage. Use the thumbwheel to raise or lower the voltage.

Note that the voltage readout will only be accurate if the voltage going into the variable channel is 22 volts. If it's lower going in, it will be lower than the display indicates going out. The variable channels manage as described in the following from The DCS O Gauge Companion 2nd Edition:

3. How Variable Tracks and Z4K Tracks Manage Voltage

There is a common misconception regarding the method by which Variable Tracks manage voltage. Based on the actual voltage being input to a Variable Channel, the Track Control Screen may display the voltage of TIU Tracks incorrectly.

The voltage displayed can be misleading due to the way that Variable Channels manage voltage. The TIU assumes that the voltage input to a Variable Channel is always 22 volts. This assumption is a natural one since many MTH transformers have a maximum output of 22 volts.

Variable Tracks

Track voltage increases when the thumbwheel of the DCS Remote is scrolled up and decreases when it is scrolled down. The voltage displayed on the Track Control Screen increases by 1/2 volt for each click above 5 volts. However, the actual voltage that reaches the tracks controlled by the TIU Track may be different because of the way that the TIU manages voltage. For each 1 volt displayed on the Track Control Screen, DCS increases the voltage at the TIU channel output terminals by 1/22 of the input voltage to the TIU channel. If the input voltage is 22 volts, the display on the DCS Remote will always correspond to the actual voltage being output by the TIU channel. If the display reads 18 volts, the actual voltage at the output terminals of the TIU channel will be:

22 volts input X 18/22 = 18 volts

However, if the input voltage is lower, the actual output voltage will be less than the display indicates. For example, if the input voltage to the TIU channel is 18 volts and the display reads 18 volts, the actual voltage at the output terminals of the TIU channel will be:

18 volts input X 18/22 = 14.73 volts

This and a whole lot more is all in "The DCS O Gauge Companion 2nd Edition", now available for purchase as an eBook or a printed book from MTH's web store site!

CLICK HERE go to MTH's web page for the book!

Thanks! 

AH! Thank you Barry-that fixed it!

Barry: can you tell he's related to me?????

- walt

LOL!  

Well I can run a conventional engine now with using the variable voltage channel of the TIU but it sure doesn't work too well! The engines don't run smoothly, the lights flicker, and the horn blows the entire time! My one MTH engine works perfectly.

Any thoughts on what might be causing this?

Any thoughts on what might be causing this?

What are you using as a transformer?

Barry, I'm using a Z-1000 on basically a 9' x 12' loop split into two blocks. 

Do you have the Z-1000 controller in the loop?  If so the recommendation is to remove it and plug the brick directly into the TIU using an adapter cord that MTH sells.   The controller chopped wave along with the TIU chop variable channel can cause issues.  Even with MTH engines.  G