Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Here is a Handy Little Volt/Amp Meter...

4850 views
14 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    August, 2003
  • From: Collinwood, Ohio, USA
  • 8,581 posts
Here is a Handy Little Volt/Amp Meter...
Posted by gmpullman on Monday, May 02, 2016 5:04 AM

I've got several—well more like a dozen—assorted power supplies for providing juice to various DC electrical functions around the layout. 

I like to use these CCTV camera power supplies because everything is there that I need, filtered DC, auto-reset overload protection and a handy barrier strip for hookup.

Sometimes I really don't know how close I am to reaching the load capacity so I decided to look for a handy panel meter.

The only thing lacking is a way to check on the load and output. I don't want to have to disconnect the load and use a VOM, I want to monitor the power at-a-glance.

Before long I came across this little guy at Amazon...

It's easy to wire, has a shunt that will read up to 10 amps at 4.5 to 30 VDC and both voltage and amperage can be adjusted using little pots on the board, if you have a good reference meter. This one, as delivered, was within a few tenths so it was good enough for me. It has a snap-in bezel but I wasn't going to get that fancy so I just Ty-Raped it to the outside of the enclosure.

http://www.amazon.com/DROK-Accurate-Voltmeter-DC4-5-30V-Multimeter/dp/B00GJK1FGI?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s02

And at just under $12 I thought it was a pretty good deal!

Thought I'd pass it along if anyone is interested...

Regards, Ed

  • Member since
    February, 2002
  • From: Reading, PA
  • 26,324 posts
Posted by rrinker on Monday, May 02, 2016 9:25 AM

 What model power supply is that? I see different models all over the place in price, if the price is right, they could eb very handy.

 You need to get a nibbler tool, then you can stick the meter right in the cover. And get some SLA batteries - if that model power supply supports it, many of them do, which would keep things going even if the power line drops - lol no lights, no fridge, but we're running trains!

                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    January, 2009
  • 4,000 posts
Posted by RR_Mel on Monday, May 02, 2016 10:06 AM

I have a pair of those meters that I bought off eBay for $3.50 ea. free S&H from Hong Kong.  Hadn’t seen them anywhere else.
 
 
I installed one above my bench power supply because it was easier to read than the analog meters with my 79 year old eyesight.
 
The second one I made mobile so that I can set it on a locomotive and measure the actual operating voltage and current.  They work great!
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
  • Member since
    August, 2003
  • From: Collinwood, Ohio, USA
  • 8,581 posts
Posted by gmpullman on Monday, May 02, 2016 2:52 PM

rrinker
What model power supply is that? I see different models all over the place in price, if the price is right, they could eb very handy.

Hi, Randy

This one is Altronix BH12DC16CB, but as you say, they are priced all over the place. I buy used ones from ebay and I have a few of the cheaper knock-offs, too.

Pelco is one of the top-line camera brands, Altronix is a step down. There are hundreds on ebay, you just have to shop carefully. I don't think I paid over $25 for any of mine.

http://www.ebay.com/sch/i.html?_sacat=0&_nkw=security+camera+power+supply&_frs=1

Many camera systems are 24 VAC so you have to watch for that, some of the power supplies are AC/DC selectable.

As I mentioned, for our use they're great since they have individual circuit protection, most have 8, 16 or 24 pair terminal strips and everything is enclosed in a nice box.

Yeah, for the signal system it would be great to have battery backup... especially for my engines that have keep alive and will keep running during a power outage!

I just got a nibbler, I was too lazy to do the sheet-metal work. Maybe I'll borrow the Greenlee punches from work... IF I get ambitious. Maybe ganging several of these on a remote panel might be a better way to go?

Mel, the one you link to looks like it needs an additional supply power? The one I got only requires the three wires with the load minus going on the yellow wire and, of course, DC plus and minus on red & black. Still, those look like an economical way to go.

Thanks, Ed 

  • Member since
    March, 2015
  • 1,315 posts
Posted by SouthPenn on Monday, May 02, 2016 8:41 PM

I believe you need a True RMS meter to read the track voltage. These meters might okay for most power supplies though.

South Penn
  • Member since
    October, 2006
  • From: Western, MA
  • 8,236 posts
Posted by richg1998 on Monday, May 02, 2016 8:59 PM

Yes, those meters are DC only.

I use the Harbor Freight meters on the AC scale. Usually about a couple dollars each.

My NCE Power Cab measures 13.6 vac. No need for true RMS meter. Same with club's NCE 5 amp system. My digital Scope confirmed this.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    August, 2003
  • From: Collinwood, Ohio, USA
  • 8,581 posts
Posted by gmpullman on Monday, May 02, 2016 9:38 PM

SouthPenn

I believe you need a True RMS meter to read the track voltage. These meters might okay for most power supplies though.

 

True.

I have an RRAmpmeter for that.

https://tonystrains.com/rrampmeter-by-dcc-specialties/

I use these meters for the auxiliaries.

I see that they have sold out at Amazon since I posted this thread but, as Mel points out, there are others. Back when I was building DC throttles and layout power supplies, analog meters were a pretty penny. My 2 Cents My 2 Cents My 2 Cents 

Thanks, Ed

  • Member since
    December, 2009
  • From: Michigan
  • 306 posts
Posted by lifeontheranch on Tuesday, May 03, 2016 8:48 AM

buyincoins.com has same meters real cheap. Also have separate V and A meters in larger display size and in blue!

http://www.lkorailroad.com/powering-the-lko-part-iii/

The camera flash exposed the unlit segments. In person everything is black on the panel. The big blue digits on black looks really cool and is super easy to read. My layout is RailPro so no RMS needed. The track bus readings (left meters) are accurate with the little meters. The Control bus (center meters) is for all things electronic on the layout - clean no spikes bus. The Accessory bus (right meters) is for noisy inductive stuff like motors and solenoids.

  • Member since
    February, 2002
  • From: Reading, PA
  • 26,324 posts
Posted by rrinker on Wednesday, May 04, 2016 7:03 PM

Do the math - RMS voltage of a square wave is the same as peak. This is different from a sine wave. An RMS meter which adjusts the measured AC voltage based on sine wave input will give an incorrect reading on DCC. This is why the readings on the cheapy meters is usually right. A high end RMS meter like a Fluke is usually designed to read properly from sine, square, and triangle waves (at least one of mine is) so those should give proper readings as well.

                       --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July, 2004
  • From: Huntley, IL
  • 250 posts
Posted by kenkal on Saturday, May 28, 2016 8:43 AM
RR_Mel, there's a bit of warnings here about customs. Did you have any surcharges or such from the feds? Note: A. Import duties, taxes and charges are not included in the item price or shipping charges. These charges are the buyer's responsibility. B. Please check with your country's customs office to determine what these additional costs will be prior to bidding/buying. Thanks. Ken
Huntley, IL
  • Member since
    December, 2015
  • 5,499 posts
Posted by BigDaddy on Saturday, May 28, 2016 9:04 AM

From US Customs and Border Protection

"Packages whose declared value is under $200 ($100 if being sent as a gift to someone other than the purchaser) will generally be cleared without any additional paperwork prepared by CBP."

Mel I think you are safe with your $3.50 meter.

Henry

COB Potomac & Northern

By the Chesapeake Bay

  • Member since
    February, 2002
  • From: Reading, PA
  • 26,324 posts
Posted by rrinker on Saturday, May 28, 2016 9:33 AM

 I've never had a problem buying packs of RC servos (I use those for my turnouts) from various China sources on ebay, and I recently bought a nice multimeter from some crazy Aussie bloke which was around $100AUD and that came through with no additional charges or fees. Oh and a few times I've ordered circuit boards from Hans Deloof in Belgium with no problem.

                    --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    July, 2004
  • From: Huntley, IL
  • 250 posts
Posted by kenkal on Monday, May 30, 2016 10:05 AM

rrinker

 I've never had a problem buying packs of RC servos (I use those for my turnouts) from various China sources on ebay, and I recently bought a nice multimeter from some crazy Aussie bloke which was around $100AUD and that came through with no additional charges or fees. Oh and a few times I've ordered circuit boards from Hans Deloof in Belgium with no problem.

                    --Randy

 

 

[quote user="rrinker"]

 I've never had a problem buying packs of RC servos (I use those for my turnouts) from various China sources on ebay, and I recently bought a nice multimeter from some crazy Aussie bloke which was around $100AUD and that came through with no additional charges or fees. Oh and a few times I've ordered circuit boards from Hans Deloof in Belgium with no problem.

                    --Randy

 

 

Thanks, Randy.  Appreciate the info.  Ken

Huntley, IL
  • Member since
    July, 2004
  • From: Huntley, IL
  • 250 posts
Posted by kenkal on Monday, May 30, 2016 10:06 AM

Thanks, Henry.  Nice to know this.  Ken

Huntley, IL
  • Member since
    November, 2007
  • From: sharon pa
  • 436 posts
Posted by gondola1988 on Sunday, June 26, 2016 10:45 AM

Do you have a discription as to how you hooked it up? I'm using a digitrax Duplex system with the 20 amp power supply. Thanks Jim.

 

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!