Skip to main content

Replies sorted oldest to newest

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.

 

Attachments

Images (3)
  • mceclip0
  • mceclip1
  • mceclip2
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

Attachments

Images (1)
  • ___Voltmeter

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

Attachments

Images (11)
  • 1033 N1
  • 1033 N2
  • 1033 N3
  • 1033 N4
  • 1033 N5
  • Z750 N1
  • Z750 N2
  • Z750 N3
  • Z750 N4
  • Z750 N5
  • Z750 N6

Add Reply

Post
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
330-757-3020

www.ogaugerr.com
×
×
×
×
Link copied to your clipboard.
×
×