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Ever wonder how much power, Milliamps, your locos use?

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  • Member since
    January 2008
  • From: Bettendorf, Iowa
  • 68 posts
Ever wonder how much power, Milliamps, your locos use?
Posted by djb39 on Tuesday, April 22, 2008 8:51 AM

I am a long time HO'er, recently restarting after a 10 year absense.  Phase 1 of my shelf layout  is well underway, with some track down.   I have 2 sound locos, Atlas Gold Dash8 with QSI, and Broadway SD40, also QSI sound equiped.  Powered with NCE power cab.  

I was interested to know how much of my 1.7 Amps available power my locos were using, I borrowed a professional "clamp around" meter from my son, an electronic eng. working on the control systems at a Nuclear power plant, to make some measurements.   Following are the results.

Note that locos draw about the same if asleep, or just sitting with sound muted, but there is some draw when parked, as compared to sitting on track with power off.   Also note that the motor in Atlas Dash8 draws less current than the B'way limited SD40.  Wish I had an Athearn Genesis to measure draw?  I do love my Atlas gold.




 

Current draw in MA
Power Cab Max current 1,700 Milliamps
Loco number

9390

3130

 
 Atlas Dash8Bway SD40Both together
Asleep

25

33

 

Awake Sound muted

26

35

 

Awake Sound on

59

50

 

Neutral Sound and horn

118

118

 

Full throttle

220

260

 

Full throttle & horn

280

320

 

1/2 throttle

140

159

 

1/2 throttle & horn

200

220

 

Stall

1000

1000

 
    
Both locos running full  

500

Both locos running 1/2

 

 

317

Both locos running 1/2, blowing 1 horn

 

 

360

 

UP Challenger 3985 photos

 

Don
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Posted by tstage on Tuesday, April 22, 2008 9:13 AM

Don,

Did you know that your Power Cab actually comes with a built-in amp usage display feature?  It would be interesting to run the exact same test above, this time using the built-in amp usage feature of the Power Cab and compare the two.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by locoi1sa on Tuesday, April 22, 2008 6:32 PM

  Hi Don

 I use my Power cabs built in amp for diagnostics of sick locos. I just found out on one loco that was lurching and sputtering that one of the motor wires was pinched when the shell was put on. The amp meter is a handy tool. I have run 5 sound and 7 non sound HO locos at the same time with my power cab. I dont have a layout but I do have 5 portable modules to run at home so the locos didnt run for long. Its surprising that the little Power cab can do so much. Probably the best investment of hobby dollars I have made. 

    Pete
 

 I pray every day I break even, Cause I can really use the money!

 I started with nothing and still have most of it left!

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Posted by Tilden on Tuesday, April 22, 2008 8:20 PM

Well, don't tell anybody,but I actually agree with our friend from the frozen north.  I have a rampmeter installed inline and get a constant amperage draw readout.  Just sitting, with a couple dozen locos on the tracks, the draw is .79 amps.  I tested this once by removing one loco at a time, watching the drop after each and ended up a .01 amp draw with no locos on the tracks.  It will also show you the additional draw when locos are running up a grade.

Really quite interesting, and useful when running several multi-unit consists.  It also allows you to avoid taxing your power supply too much.

Tilden 

  • Member since
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Posted by richg1998 on Tuesday, April 22, 2008 8:47 PM
 Tilden wrote:

Well, don't tell anybody,but I actually agree with our friend from the frozen north.  I have a rampmeter installed inline and get a constant amperage draw readout.  Just sitting, with a couple dozen locos on the tracks, the draw is .79 amps.  I tested this once by removing one loco at a time, watching the drop after each and ended up a .01 amp draw with no locos on the tracks.  It will also show you the additional draw when locos are running up a grade.

Really quite interesting, and useful when running several multi-unit consists.  It also allows you to avoid taxing your power supply too much.

Tilden 

 

I have done the same at our club and my home layout. I use a DIY DCC amp meter that compares very well with a borrowed commercial ramp meter.

http://home.cogeco.ca/~rpaisley4/DCCAmmeter.html

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.

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Posted by wheeler on Tuesday, April 22, 2008 9:37 PM
 tstage wrote:

Don,

Did you know that your Power Cab actually comes with a built-in amp usage display feature?  It would be interesting to run the exact same test above, this time using the built-in amp usage feature of the Power Cab and compare the two.

Tom

Got Time to explain where it is here?

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Posted by richg1998 on Tuesday, April 22, 2008 11:54 PM

This link might explain a little.

http://www.members.optusnet.com.au/nswmn1/power_cab.htm

Look at page 59 in the below document.

http://www.ncedcc.com/power_cab_manual_v1.28.pdf

This feature is hardly mentioned.

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.

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Posted by tstage on Wednesday, April 23, 2008 12:42 AM
 wheeler wrote:
 tstage wrote:

Don,

Did you know that your Power Cab actually comes with a built-in amp usage display feature?  It would be interesting to run the exact same test above, this time using the built-in amp usage feature of the Power Cab and compare the two.

Tom

Got Time to explain where it is here?

wheeler,

Sure.  I had to go downstairs and turn on my Power Cab first to find the sequence.  Here it is:

  1. Press PROG/ESC button 6 times
  2. "CAB PARAMS" on LCD screen - Press ENTER
  3. "SHOW TRK CURRENT 1=Y" on LCD screen - Press 1 for Yes
  4. Press PROG/ESC button to return to operating screen

The ammeter replaces the fast clock display in the upper right corner of the LCD screen.  Once you turn off your Power Cab though, the ammeter resorts back to the fast clock display the next time you turn your Power Cab on again.  This feature also doesn't work when the Power Cab is used in conjunction with a Smart Booster.

Hope that helps... 

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
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  • From: Poconos, PA
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Posted by TomDiehl on Thursday, April 24, 2008 9:58 AM
 djb39 wrote:

I was interested to know how much of my 1.7 Ma available power my locos were using, I borrowed a professional "clamp around" meter from my son, an electronic eng. working on the control systems at a Nuclear power plant, to make some measurements.   Following are the results.

You've got a bit of a problem with terminology and abbreviations here. According to this sentence, your power supply puts out 1.7 million amps. Thats WAY beyond arc welding! An upper case "M" indicates "Mega" or times one million. A lower case "m" indicates "milli" or divided by 1000. These standards go all through electronics and the metric system.

Properly stated, your power supply puts out a maximum of 1.7 Amps or 1,700 mA. Or .0000017 MA.

Smile, it makes people wonder what you're up to. Chief of Sanitation; Clowntown

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