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Discussion Starter · #1 ·
Never had one and never used one. Watched some stuff but everyone's application is different. Mine is not complex.
I am starting a Lionel Legacy engine with cw-80 transformer on Fastrack. I'm aware after a certain number of connections & distance (not so much) and load the need for drops will vary. Aside from just using the train to tell me where and when more power is needed by slowing now or I assume lights not consistent. How would I use a meter?
I certainly can see how continuity works and that's simple. Not sure if I need to worry about amps as I'm doing a floor layout, no accessories (for now), no switches, just a 2-8-0 Consolidation, and then several passenger cars.
Is it just drops in the voltage then which would cause my problems as I get further from source past more and more connections. Can you just put probes on the Fastrack( if so which 2 would I use) at various places and see if it maintains 18v? I think that's going to be at full power of a Lionel cw-80.
If it's relevant I am "not" looking to run the train at full speeds, and, my transformer/10" terminal track will be on a series of 30" straights.
Thanks for any info on how a multimeter might help me .
Cheers all
 

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Here are some additional uses:
A multimeter set to measure resistance is good for testing continuity (making sure there are no breaks in a circuit). It's also useful to figure out if you have a short circuit (continuity where there shouldn't be). Good for testing switches, too. And you can test for bad armatures by testing continuity between commutator sections.

When set to measure DC voltage, I use it to figure out the polarity.

When set to measure diodes, I use it as a quick way to test LEDs and to figure out their polarity.

When set to measure current, I can see if something is drawing more than I want it to draw. I can also use it to help determine what size fuse or circuit breaker I may need.

My first multimeter was a tiny analog meter I got at a hardware store. Then I got a free one from Harbor Freight (those are nice because they have a battery tester for 1.5V cells). Then I got a nicer UNI-T that ran me around $60 and it does more stuff than I need it, but the quality is better than I could get a the home center.

I'd recommend getting a cheap one from Harbor Freight, it'd be good enough to start out with.
 

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Discussion Starter · #3 ·
I know there's a ton of uses for them even just to have around the house for other purposes. I just have never "needed" one. For this case though, would you be able to use it on AC Voltage and just use the probes around a layout and see if there were voltage drops? Is it drops in voltage that would alter my lights brightness and train speed and dictate the need for bus/feeders?
So if i open up the transformer to wide, 18V would be transmitted to the track. That number will not be the same at other points in the track. Would a voltmeter , at the furthest point away,in either direction from the source, not read it's lowest number (provided there were no resistance/continuity problems). Could I just use a voltmeter directly to determine where drops would be needed?
My draw will just be the 2-8-0 and at most 6 LED lit passenger cars.
I believe 8-18v is needed to run. What happens if voltage at a certain point were to drop to 16 vs 12 vs 8. (or am I right off track here. ;))
 

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Never had one and never used one. Watched some stuff but everyone's application is different. Mine is not complex.
I am starting a Lionel Legacy engine with cw-80 transformer on Fastrack. I'm aware after a certain number of connections & distance (not so much) and load the need for drops will vary. Aside from just using the train to tell me where and when more power is needed by slowing now or I assume lights not consistent. How would I use a meter?
I certainly can see how continuity works and that's simple. Not sure if I need to worry about amps as I'm doing a floor layout, no accessories (for now), no switches, just a 2-8-0 Consolidation, and then several passenger cars.
Is it just drops in the voltage then which would cause my problems as I get further from source past more and more connections. Can you just put probes on the Fastrack( if so which 2 would I use) at various places and see if it maintains 18v? I think that's going to be at full power of a Lionel cw-80.
If it's relevant I am "not" looking to run the train at full speeds, and, my transformer/10" terminal track will be on a series of 30" straights.
Thanks for any info on how a multimeter might help me .
Cheers all
On you "dogbone" layout, just attach the transformer leads to the dip and then another drop on the other side of the dip. That will cut the distance the volts have to travel nearly in half.

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Never had one and never used one. Watched some stuff but everyone's application is different. Mine is not complex.
I am starting a Lionel Legacy engine with cw-80 transformer on Fastrack. I'm aware after a certain number of connections & distance (not so much) and load the need for drops will vary. Aside from just using the train to tell me where and when more power is needed by slowing now or I assume lights not consistent. How would I use a meter?
I certainly can see how continuity works and that's simple. Not sure if I need to worry about amps as I'm doing a floor layout, no accessories (for now), no switches, just a 2-8-0 Consolidation, and then several passenger cars.
Is it just drops in the voltage then which would cause my problems as I get further from source past more and more connections. Can you just put probes on the Fastrack( if so which 2 would I use) at various places and see if it maintains 18v? I think that's going to be at full power of a Lionel cw-80.
If it's relevant I am "not" looking to run the train at full speeds, and, my transformer/10" terminal track will be on a series of 30" straights.
Thanks for any info on how a multimeter might help me .
Cheers all
A multi-meter is indispensable for many of the things we do in model railroading, but figuring out if and where to locate power connections IMHO is not one of them. As you say, the operation of the engine will tell you just about everything you need to know about the location of power connections.

I've seen some nice write-ups that go into great detail about voltage drop and the distance between the transformer and the engine powered by it, but it's really very simple, with no multi-meter required: every conductor (like a track rail) has a certain resistance per distance unit (inch, foot, etc.), and the further the electricity has to travel, the more resistance it has to overcome, which will in turn reduce the amount of voltage and power available to drive the engine. Poor connections (between track sections, at wire junctions or between the track and the engine) can increase that resistance and make the problem worse. Conversely, cleaning the track surface and wiring contacts, and making sure the track connections are corrosion free, are all steps toward getting better performance out of any given setup (and yes, a multi-meter can be helpful in confirming there is or isn't any such connectivity problems, and where, and that the problems have been successfully sorted).

If after all that you still have places on the layout that seem under-powered, adding a power connection in the middle of that section will likely reduce if not eliminate the remaining problem. Unless you are really compulsive about trying to know exactly what's happening electrically on your layout at all times, I see little need for anything a multi-meter might tell you, unless/until you encounter a discernible problem. Good luck, in any event!
 

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Is it just drops in the voltage then which would cause my problems as I get further from source past more and more connections. Can you just put probes on the Fastrack( if so which 2 would I use) at various places and see if it maintains 18v?
yes.
if ~18V is the track voltage from the throttle with the engine running. measure it at the farthest point from the throttle with the engine running near that point.

if there is too much of a difference(?V), try adding addition track connections or use heavier gauge wire
 

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I don't think you need a multimeter if it's just to check that you have good connections on your track. As suggested on another thread, just run the loco and if it slows down far away from your lock-on/power drop, you know that you need to add another lock-on/power drop. That said, I used one to pinpoint some bad connections on some 80 year-old tubular track so I focused on improving those connections.
 

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Discussion Starter · #10 ·
A multi-meter is indispensable for many of the things we do in model railroading, but figuring out if and where to locate power connections IMHO is not one of them. As you say, the operation of the engine will tell you just about everything you need to know about the location of power connections.

I've seen some nice write-ups that go into great detail about voltage drop and the distance between the transformer and the engine powered by it, but it's really very simple, with no multi-meter required: every conductor (like a track rail) has a certain resistance per distance unit (inch, foot, etc.), and the further the electricity has to travel, the more resistance it has to overcome, which will in turn reduce the amount of voltage and power available to drive the engine. Poor connections (between track sections, at wire junctions or between the track and the engine) can increase that resistance and make the problem worse. Conversely, cleaning the track surface and wiring contacts, and making sure the track connections are corrosion free, are all steps toward getting better performance out of any given setup (and yes, a multi-meter can be helpful in confirming there is or isn't any such connectivity problems, and where, and that the problems have been successfully sorted).

If after all that you still have places on the layout that seem under-powered, adding a power connection in the middle of that section will likely reduce if not eliminate the remaining problem. Unless you are really compulsive about trying to know exactly what's happening electrically on your layout at all times, I see little need for anything a multi-meter might tell you, unless/until you encounter a discernible problem. Good luck, in any event!
Ya, I guess I'm just trying to spend some money :)
 

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Discussion Starter · #12 ·
A new question about the multi meter. I have a cw80 transformer and it was blinking red. I checked on things and it was fine, but then it seems to have blown it's fuse. In the interests of not wanting to blow transformers, how can I use a multimeter to test the transformer out of the box, then once hooked to the track, what test could I do on a 40" straight of Fastrack (a 10" then 30") to ensure it's appropriate to place my Legacy engine.
Is there a way to use the meter to test the engine to tell if it's what's causing the transformer to have problems?

I want to go minimal, adding factor by factor so I can detect exactly what changes, when and if there is a problem.

Thanks
 

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This is one tool you will want/need often in model railroading. And not just always for your track. I think I use mine for continuity tests (Ohms) more than voltage readings. Here is an example of my latest use/test when I had an engine die on a switch.

 

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I want to go minimal, adding factor by factor so I can detect exactly what changes, when and if there is a problem.
you can
  • measure transformer voltage at various settings without it connected to track
  • check for a track short by measuring the resistance across the track connections
  • measure track voltage at various settings with transforrner connected to track
  • measure the resistance of the locomotive (across appropriate wheels). should not be ~0
  • measure track voltage at various settings with engine on track, prepared to stop if track voltage is substantially (??) lower than expected or if engine doesn't appear to start running
 

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The CW 80 uses a partial duty cycle sine wave to control power (throttle) to a loco. Compare that with a Lionel post war transformer that varies the amplitude of a pure sinewave to controll power. Most all budget and moderate priced multimeters will not measure the CW 80 output correctly. They measure the peak and calculate the AC RMS value from that. Since the CW 80 output always has the same peak, they'll always measure full throttle regardless of the throttle position. You'd need a high end "True RMS" meter to measure the effective voltage of the CW 80.

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I use the Fluke 117, I bought it several years back after my 20+ year old Fluke 77 finally went out of cal. It was cheaper to buy a new meter than get the #77 calibrated!

I actually have a number of multimeters, but the Fluke 117 and my Fluke 8012A on the bench get used most often.

One handy meter I also get significant use from is the
Harbor Freight Clamp-On meter, and it's dirt cheap! Being able to measure AC current without breaking the connection is really useful with model trains!

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Discussion Starter · #20 ·
This is one tool you will want/need often in model railroading. And not just always for your track. I think I use mine for continuity tests (Ohms) more than voltage readings. Here is an example of my latest use/test when I had an engine die on a switch.

Beautiful layout Ron, (nice name too). Love your elevated town over the train. Thanks for the simple video of your usage.
 
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