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Finding the AC meters is always the tricky part, most of the digital meters are of the DC variety.  A few years ago, I painted an old beat up PW boxcar and installed two AC 0-20V meters, one on each side.  Obviously, I also had to install collector trucks to grab the voltage.

 

The tricky part was the meters required a totally isolated DC supply besides the measured voltage.  So I had to cobble together a little supply that fed a 12VDC<->12VDC Isolated switching supply module.  This powered the meters and they can then measure the track voltage.

 

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Last edited by gunrunnerjohn

Note that the separate DC supply to power the meter must be TOTALLY isolated from the voltage being measured.  That's a key point!

If you do a search on eBay for the exact title below, the top result that comes up is a suitable meter, and they have it in the proper voltage and current ranges.

Red LED Digital Digit Voltage Voltmeter Current Ammeter AC Meter Panel 3 1/2

Here's the drop-down that shows you all the varieties available.  You'll note the 0-10A and 0-20V meters are there, ideal for most layouts.

___Voltmeter

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Are looking for just track voltage in general or voltage in a section as the train rolls down the track. If you want a freight car with a voltage meter in it, Lionel made a Great Northern work car with a meter some years ago .

If just track voltage in general, I use a digital multimeter from Harbor Freight with the probes stuck in to the ends of a spur track of Gargraves or tubular track. I  have one attached to my transformer and one on a spur. That way I can see the voltage drop through the tracks. 

At times Harbor Freight offers the meters free or for $1.00 with purchase . I bought a bunch of them, they last about 5 years at constant usage.  

Thanks for feedback!   I am looking to monitor the output from transformers to lighting which have a voltage capacity which is less that the max output of the transformer.  I have already melted a few bulbs and so I want a way to ensure it doesn’t happen again. 

i have a basic variable out transformer which I intend on putting stops on so I cannot move the lever beyond the max output that I need.  Plus it looks way cool with all the meters in the control panel 😎!

Well, I ordered one of each of the ones I posted, but the results are less than stellar with a chopped waveform transformer. On the bright side, they came quickly.

I suspect those kind of results aren't going to please many people.  There is a 75 ohm resistor across the output for a small load, this prevents the stray AC from giving us false readings.

The meter on the right is a Fluke 8012A True-RMS meter, the meter on the left is the one I described in a post above.  I don't expect the ammeter to do any better with a chopped waveform, so these aren't actually ready for any layout using one of the many chopped waveform transformers.

The meter looks pretty good with a pure sine wave from the 1033!

1033 N11033 N21033 N31033 N41033 N5

 

Hot stuff, let's try a Z750.  UGLY, massive errors across the whole band!

Z750 N1Z750 N2Z750 N3Z750 N4Z750 N5Z750 N6

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https://ogrforum.ogaugerr.com/...2#149239177048400272

gunrunnerjohn mentioned that the DC power supply must be isolated from the tested voltage. so i bought the same meters on ebay (voltage and current) and also AC to DC converter to provide the 5v DC needed to power the meters. hooked the converter to one of my accessory Z1000’s and then tried to display the voltage from another Z1000 providing track power. as soon as i connect everything, the external fuse blows on the track powering Z1000. is this because all the transformers are connected? how do isolate the DC power to the meters? would i have to use a plug similar to those that supply 5v power to lighted menards buildings?

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