Voltage drop on Z4000 when using a Remote Commander Receiver ?

What are the no load readings?  The Receive is just remotely controlling the Z-4000, not actually passing voltage.  I would think this is more of a software issue then a electronic voltage drop.  Sounds like the remote is not allowing the voltage to go to full.  G

What's the version of DCS being used? To George's point above, this is a software issue, possibly within DCS.

A second set of data points should be obtained by using the Z4000 Remote Commander receiver with its companion Z4000 Remote Commander handheld remote. This would remove the DCS Remote's software as a contributing factor.

Thank you to both of you for your answers.

Belonging to the same train Club with Daniel Auger, I am informing you that the DCS version is 4.30 and that I will perform the tests with the Z4000 remote commander handheld tomorrow.

I will post the results as soon as I can.

It was nice to chat with you this morning Barry.

Jean-Paul,

It was nice to chat with you this morning Barry.

Yes, it was good talking to you, as well!

Good Evening,

In reply to the questions above, here are the results of additional tests performed today.

1) Question From GGG: What are the no load readings?

Answer:

Without Remote Commander, Handles at max setting: 

   LEFT CHANNEL:

   Voltage measured at Z4000 Output: 21.93 Volts

   Voltage indicated on the Z4000 front panel: 22 Volts 

   RIGHT CHANNEL:

   Voltage measured at Z4000 Output: 21.99 Volts

   Voltage indicated on the Z4000 front panel: 22 Volts

With the Remote Commander Receiver at max setting on the DCS Remote:

   LEFT CHANNEL:

   Voltage measured at Z4000 Output: 24.12 Volts

   Voltage indicated on the Z4000 front panel: 22 Volts 

   RIGHT CHANNEL:

   Voltage measured at Z4000 Output: 24.10 Volts

   Voltage indicated on the Z4000 front panel: 22 Volts

2) Question From Barry: What's the version of DCS being used?

Answer:  V4.3

Note 1: As a "companion Z4000 Remote Commander Handheld" was not available today, this specific test could not be performed.  A DCS remote was used.

The no-load tests and the with-load tests seem both to indicate that something operates very differently inside the Z4000 when the Voltage command is coming from the Handles, or from the Remote Commander Receiver + DCS Remote.

Any help would be appreciated to understand this behavior.

Thanks,

Daniel

Note: Considering that the Power (Watt or VA) varies to the square of the Voltage for a constant resistive load, the Voltage drop of ~10% caused by the Remote Commander is leading to a lost of power of ~19% [1-((1-.10)^2)]

Ref:

I=V/R

W=V*I

W=V*V/R

W=V^2/R

I just tried your experiment with the Z4000 and the remote.  I also don't have a Z4000 remote, only my DCS remote.

I used an 8 ohm 75W resistor as a load to give the transformer something to do.

At 20V indicated on the transformer and the remote I got about 18.25 volts on a true-RMS meter across the resistor.

I then removed the remote receiver and set the Z4000 to 20 volts with the handle, I got about 19.25 volts on the resistor.

In both cases the Z4000 was reading 20 volts on it's display.

It appears there is some sort of voltage drop using the remote, though I can't imagine why that would be.  However, I can confirm that you're are not imaging things.

So with the receiver plugged in and voltage raised to 20V what is the current draw of the receiver.  I am sure it gets power from the Z-4000.

For what it is worth, when testing boards.  If I raise the voltage on the Z-4000 manually and have it a 14V with .3amps, then turn smoke on the voltage will droop.  So I don't think it is finely tuned for voltage regulation, like a power generator would be.

So what ever that initial voltage drop once current flows is compensated for manually, I believe the voltage holds.

John's voltage drops are not as significant as original poster, and he is pulling about 2.5 amps.

Once you get that heavy drop, can you use the remote to raise voltage back up?  G

I think the significant item here is that I get different voltages using the Z4000 receiver than using the handles.  I presume that if I read 20 volts on the display, that it should be the same in either environment.  I certainly agree that since the remote is sending the voltage request that this could be a simple software issue communicating between the remote receiver and the transformer or the interpretation of the voltage being commanded.

I think it's safe to say that it's an anomaly that probably shouldn't exist, but it obviously does.

It also occurred to me that I may have introduced an error into the measurement.  I was measuring the voltage at the load, not taking the test leads into account.  I redid the test to measure the voltage at the transformer.

Using the handle, at 20 volts on the dial, I get 19.8 volts on the bench meter.  Note that there is an area of uncertainty in the panel voltage reading, you can vary it almost a volt before the panel changes as it has 1 volt resolution at that voltage.  I tried to center it in that window.  Both the panel amps and my clamp-on registered 2.4 amps.

Using the remote, at 20 volts on the dial and the remote, I get 18.3 volts on the bench meter.  I get 2.23 amps on the clamp-on, and there is no amp reading on the transformer in remote mode.

Using the new figures, I see where we are indeed getting almost a 10% loss in power using the remote at the same apparent settings.

So under load, after initial reading, can you dial up the Voltage to compensate with the remote?

I can get about half of it back.   Turns out at full voltage with the handles, the transformer bounced between 21.7 and 21.0 for some reason.  The amp readings followed it, so it was really happening.  Even the display bounced between 22 and 21 volts.  If I drop the displayed voltage to 20 volts, it gets smooth again and it'd really putting out 20 volts.

With the remote in use, I went to 22 on the display and I had 19.8 volts real voltage at the output terminals.  However, it didn't bounce around at the full command voltage, just didn't get up as high.

It's somewhat odd that the remote operates differently than the levers, I actually wouldn't have expected that.

It is interesting, but I guess the manual pot resistance changes to address FET Power control, could be significantly different then the electronic adjustment done via remote controlled circuit.  G

You would think that digital to digital that they'd be able to get the voltage to agree with the display, that's what mystifies me.

Good Evening,

As recommended by Barry B., more tests have been performed on the Z4000 with three different methods of control: 

1) Z4000 Handles,

2) Remote Commander + DCS Remote v4.3,

3) Remote Commander + Remote Commander Handheld

The Z4000 with a Remote Commander, controlled by either the DCS Remote V4.3 or the Remote Commander Handheld, shows significant lost of Voltage and Power.  The results are slightly different at MAX setup, but identical at any other setup.

Below and attached are the detailed results:

Daniel

My brief series of tests with just the DCS remote seem to track these results pretty well.  I don't have the Z4000 remote handheld, just the receiver.

All I can think is that in manual the Z has circuity to compensate some what for the voltage droop as current increases.

Almost looks like with the remote, it sets a voltage but the current causes a voltage drop that is not compensated for.

The Z-4000 design guys would have to explain this.  G

I think you're right about that George, it certainly seems that the behavior is "baked into" the Z4000 and remote receiver combo.

Is it possible that the Z4k circuitry monitors the voltage requested by the remote (when Z4k remote is used) and not its output voltage at the terminals, but when in manual mode, the Z4k monitors the output voltage at its output terminals? This may explain the discrepancy in output voltage readings...

properly designed, the Z4K should look at the requested voltage from the remote AND its output voltage terminals and compares the two to compensate...

Anything's possible Sam, it is curious that it differs.

I'm a bit surprised that the meters don't track the output voltage, you'd think they'd be measuring at the output for the voltage and amperage displays.

That's one reason I use the Lionel PowerHouse 180 bricks.  My Z4000 mostly gets out for bench tests.  It's handy for working on PS/1 stuff, the program modes make it easy to setup the locomotives.

These transformer are not fully regulated like a Power Generator would be, or a critical transformer for sensitive equipment.  As Current increases there will be a drop in voltage.  Same with a Power House 180 brick.  That is the reason the no load voltage is usually a little higher.  If you had a VM on the brick you would see a drop also.

So set it to about 19VAC unloaded and run trains. Don't over think it. 

Yep, I like the PH180 because it tops out at around 18 volts.  With my higher voltage here, it's about 18.5 volts with no load.