Yes. But I think I would go for a 10-ampere meter instead of 20:
http://www.ebay.com/itm/DC-0-10A-Round-Analog-Ammeter-Panel-AMP-Current-Meter-DH62-Neednt-with-Shunt/181311593829
Bob Nelson
Would these meters be good enough for a workbench repair area?
http://www.ebay.com/itm/AC-0-30V-Round-Analog-Voltmeter-Voltage-Panel-Meter-AC-DH52-Directly-Connected-/181390575716
http://www.ebay.com/itm/AC-0-20A-ROUND-Analog-Ammeter-Panel-AMP-Current-Meter-DH62-Neednt-with-Shunt-/181311593823
Bob..... there used to be a TV western in the early 1960s starring Richard Boone called "Have Gun Will Travel." Do you make house calls?
Jack
IF IT WON'T COME LOOSE BY TAPPING ON IT, DON'T TRY TO FORCE IT. USE A BIGGER HAMMER.
I think we're in agreement; I deliberately posted the result for "ampmeter" to show that it suggests correcting it to "ammeter".
It is possible to make your own AC voltmeter and ammeter from DC meters. You can do it by putting a bridge rectifier upstream of the meter, using one rated for the expected current for the ammeter. One catch is that, even if the rectifier were perfect, each meter would read 10 percent low. On top of that, the voltmeter's scale will be squashed to the left at the bottom by about a volt. The ammeter's scale will not be squashed but the rectifier will steal about a volt from your trains. Of course, you can redraw the scales if you have the patience and another pair of accurate meters to use for calibration.
lionelsoni
Bob,
Perhaps my source can lick your source. Check out what Merriam-Webster has to say about the spelling, definition and pronounciation of "ammeter." The problem with "ampmeter" is that it is unpronounceable this side of Bosnia.
http://www.merriam-webster.com/dictionary/ammeter
Dewey, I can't understand how a conventional two-terminal meter would do that.
As for the spelling, here's what Merriam-Webster has to say:
http://www.merriam-webster.com/dictionary/ampmeter
Thank you A & Y Ry, and all others. I'm again amazed at the efforts you all put forth to share your knowledge on the forum.
runtime
Bob
As regards electrical polarity you are of course as usual correct[ac has no polarity]. But my Der 670 meters and Shurites both produce a reverse needle position when wired transformer flow-to [-] negative "marked" post.
Spelling?
Amp meter
ammeter
Lo it be for a lowly [and obsolete]sparktrician to argue with a MIT scholar!
AC meters, whether voltmeters or ammeters (note spelling) have no polarity--there is no + nor -. The two terminals are interchangeable.
The ammeter is really helpful to monitor engine performance. On the layout I can tell when a loc is needing to be lubed, or if I'm running with too much load. The American Flyer engines were spec'd out to have an optimal amperage pulling four box cars at I think it is 9 revolutions per minute around a 120" oval. Most of the time the spec is less than 2 amps. The test rig is great for troubleshooting and evaluating performance gains through cleaning lubing and the like
Jim
You wire the AC voltmerers {Vac] across-the-line, one terminal connected to the transformer Hot output conductor[from "A", or "D" post } and the other conductor to the transformer Common "U" post or outside rail circuit.
The Amp meter [Aac] is wired "inline" of the hot wire circuit. On most [edit: see Bob Nelson's opine] meters the feed wire from the transformer "A" or "D" post is connected to the (+) terminal post of the Aac meter and the (-) meter terminal post connects to the conductor out to the center rail. This +/-connection is only important to properly orient the meter pointer.
Google the Shurite Meters which are affordable Toy Train AC analog "moving magnet" meters. They will run about $25 each or less. Higher quality "Iron Vane" meters run about $85-115 each and are unecessary for Toy Train circuit monitoring. The moving magnet meters are about 2-2-1/2% accurate.
When reviewing the catalogs--Mouser, ALLElectronics, Newark Electronics, Shurite,etc, be sure that you are looking at AC Meters not DC which are very prevalent in the llistings. Generally you want about an 0-15 amp range and an 0-25 volt range in your Toy Train power district meters, but other ranges are available.
I was importing DER 670 meters a few years ago at a USA landed/customs cost of $28-$32 a pair [one Aac, one Vac]but today the air freight cost in the Pacific Rim has raised the single meter cost to about $25 each.
You need a pair of meters for each separate layout power district and you want to connect them at or near the transformer terminals to read the total load upstream. The amp meter requires heavy gauge wire [#12 or #14]because it carries the entire power district load. The Voltmeter can have light wire [#18] because it simply is reading across the line.
Most all of the meters require a 2" round hole in the masonite,aluminuim.etc that you mount on; for the "barrel" of the 2-1/4" x 2-3/4"' face or dial[typical] and the acrylic face has 4 bolt [machine screw] holes.
Very nice setups...and I've been thinking of metering my layout.
Where in the circit would I put the meters, and what would I be measuring? Eg- would I be measuring the E & I at the place where the power connects to the track? or the power where the engine is at any moment?
Obviously ignorant,
Try Newark electronics, they have analog volt & amp meters for around $20.00 each, I think the website is www.newarckelectronics.com You will need to make your own panel from wood or metal to custom fit these meters.
Lee F.
The voltmeter and ammeter would be available from Scotts Odd's and Ends, (advertizer in CTT)
Here is how I did mine
The 30B and 17B had built in voltmeters and the 17B also has an ammeter. I added the ammeters to the control panel
The test rig has the voltmeter and ammeter. I'm thinking the meters were about $18 each
Try All Electronics. www.allelectronics.com
Kurt
I am trying to scope out my control pannel for using KW transformer using both throtles with blocks and on -off-on togle switches for 12 blocks and 12 turnouts. Half of system to be FASTRAK and half "o -31". I would like to include an amp & volt meter for each throtle. Ihave only been able to find in Allied site and catalogue. but cost are appr. $ 60 each. Anyone know of les expensive option.
Thanks Ellis
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