how can I check if track is live?

[renard80]

Apologies for what must be a basic question. Elink and railmaster were running fine until we moved the board with its layout to a new situation. Everything still boots up ok but locos don't move upon command. 

Dumbo question: how can I check if power is reaching the track? Gently,  please,  I ain't the smartest with electronics! 

[Chrissaf]

Renard,

Stick your tongue on one of the track rails. If you have to be scrapped off the ceiling then it is live.

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Seriously though, if you have a meter of some description then set it to AC volts 20 volts range and you should measure a voltage of about 14.7 volts give or take 0.5 volts. If no meter to hand then a 12 volt car side light bulb across the rails should light up brightly. Last resort, if nothing of above to hand, apply a short circuit across the track, you should hear a buzzing followed by the controller tripping (safety cut-out). I would remove all decoders from the controller output first before doing that to be on the safe side (accessory decoders, if present, as well as any locos on track).

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Alternatively, If you bridge the track with wet fingers you may feel a slight tingle indicating track voltage as being present. Wet fingers being less sensitive than one's tongue. But the wet finger test may not be totally conclusive.

[Graskie]

I can see you're a bit foxed by this situation, renard. Have you very carefully checked your connections to the track since moving your board? One crude method of seeing if power is going through the tracks is to deliberately cause a short with something metal across both tracks. If there is power there, you should see indications of a short on your control equipment. Otherwise you could try wiring a small bulb to each track and see if it lights up. Ideally you need to buy a cheap simple track power tester. I personally use a Proses Track Voltage Tester which you can buy online.

[Graskie]

Sorry, I got beaten to it by a perhaps more technical reply from Chris.

[dynax]

Renard,

Stick your tongue on one of the track rails. If you have to be scrapped off the ceiling then it is live.

.

 

.

 

 

 this won't work, you need to bridge both rails with your tongue to make a circuit,

 

[Chrissaf]

Not if there is an electrical path to earth. I'm certainly not going to try it to test the theory though.

[Chrissaf]

Not if there is an electrical path to earth. I'm certainly not going to try it to test the theory though.

 .

Changed my mind, feeling brave. Decided to test theory. Making sure I only touched ONE rail with my tongue. No shock (I was wearing rubber soled slippers though), I wasn't brave enough to try it again bridging both rails. The wet finger test also gave a zero result, so an electrical test aid (meter, bulb, track tester etc) or an applied short circuit only true way to test for live track. 

[poliss]

Coin across the rails is the simplest method. If it doesn't register on the controller, then power isn't getting to the track. Double check all connections and that the mains socket you are using is actually live. Plug something else into it.

[96RAF]

The tongue test works with a 9v brick. My old Jack Russell kept yelping and I wondered why until I found the battery in his bed. He yelped everytime his nose bridged the terminals or he licked it. I have no idea where he got it from but it was his favourite toy and he looked miffed when I took it off him.

So 15V should really make your tongue tingle.

[renard80]

Thanks for all the advice.

Fortunately I have found a multimeter, so don't have to risk my life with wet fingers or tongue!

So here's where I am now:

Elink is connected to mains and showing green light. Track wires are connected into 'Track' on elink. Elink is not connected to computer.

Presumably, if connections are sound the track should now be live (?).

The multimeter dial has an AC volts area with just two options - 750 or 200. There isn't a 20 volts option, Chris. So I switch it to 200 and the display comes up 00.0

Touch the probes to opposing track rails - and the meter display doesn't move from 00.0

SO - have I done correctly? If so, presumably it means either the wires from elink to track aren't connected properly, or the elink is faulty.

Further advice will be gratefully received, please. (See, I told you I am a dumbo . . . )

[Fishmanoz]

Try connecting the probes directly to the track output of the elink renard. 

[poliss]

Here's a page about multimeters with simple instructions and videos that even I can understand. :-)

https://learn.adafruit.com/multimeters/overview

[Chrissaf]

My reference to the tongue test was meant to be taken as a joke, somehow it got out of hand. As Fishman says, try checking the output of the eLink. If that is good, then fault lies somewhere between eLink and track. It is possible that your meter's limited 200 volt range may not be sensitive enough to measure circa 15 volts. It can't be a very modern meter to have such limited features. Is there another AC voltage source that is known to be working that you could test your meter on to prove it is working and that you are using it correctly? It sounds like your meter is an automotive electrical meter.

.

Alternatively, could you revert back to trying the 'bulb test' to be doubly sure your meter is reading zero correctly. Failing that the 'short' test.

[poliss]

I expect you told people to stick their fingers in the HT lead on your motorbike to see if it was working. Lots of fun to be had there. :-)

[renard80]

Thanks to all for the further advice. Too late at night now, will try your suggestions tomorrow.

Great set of helpful people on here, many thanks!

[poliss]

If your multimeter doesn't look similar to the one at the start of the video, it may not be suitable. It should have a 10A socket at least.

[Chrissaf]

I expect you told people to stick their fingers in the HT lead on your motorbike to see if it was working. Lots of fun to be had there. :-)

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Not far from the truth there Poliss. When I was a telephone field engineer in the days of plug and cord manual switchboards. We would trick the girl operators into holding the brass plugs in their hands and then give them a burst of 85 VAC ringing. We were used to that level of voltage and could keep a calm straight poker face ignoring the shock we were giving ourselves to lull the girls into a false sense of security.

[renard80]

An engineer friend expressed surprise that I was being advised to set the meter to AC. He recommended DC (I know nothing! ).

So, checking with DC revealed no power on the track but there was power from the Elink.  Repaired the connection between Elink and track,  checked track again with DC meter and all now OK. 

Many thanks to all for helping. 

[2e0dtoeric]

Glad it is working, but I'm surprised the meter read anything, when set to dc, because the digital signal coming to the track from whatever controller you use is superimposed on AC.  :-)

[96RAF]

... set the meter to AC. He recommended DC (I know nothing! )...

...Neither does he about DCC foxy

The DCC waveform is psuedo AC in that it is approx 15V + & - about zero volts, but in a square(ish) waveform as opposed to the sinusoidal (spelling?) waveform of mains AC in your house.

[Chrissaf]

An engineer friend expressed surprise that I was being advised to set the meter to AC. He recommended DC (I know nothing! ).

.

Your friend's knowledge of model railways is obviously limited to analogue (DC) controllers. The output of your eLink DCC controller is as RAF says. Not true AC but more like AC than DC. This link shows some example DCC voltage waveforms taken with an oscilloscope, clearly the waveforms in these images are not DC.

[Fishmanoz]

You oided your sinuses perfectly RAF.  And if your meter read something on a DC setting foxy, the meter is broken.  Glad you've fixed the problem though.

[96RAF]

if your meter read something on a DC setting foxy, the meter is broken

Think about it:

An analogue meter (with a needle) set on DC range will in theory swing back and forth from +15 V to -15 V but due to the DCC frequency it would change polarity so fast it probably wouldn't even move from zero V, maybe just flicker a volt or two.

A digital meter (with LCD screen and numbers) would react quicker, but the numbers would be continually changing so there would never be a steady reading on DC range.

Set either meter to AC range and it will read an indicitive value, but not an accurate one as the meter is set to interpret sinusoidal wavefrom not squarish DCC.

Now you can confidently explain to your engineer friend foxy what DCC is all about.

[Gravy]

Apologies for what must be a basic question. Elink and railmaster were running fine until we moved the board with its layout to a new situation. Everything still boots up ok but locos don't move upon command. 

Dumbo question: how can I check if power is reaching the track? Gently,  please,  I ain't the smartest with electronics! 

 This link gives you method to make a device to prove your track voltages, requires some soldering skills;

http://www.wiringfordcc.com/track.htm

Apologies for what must be a basic question. Elink and railmaster were running fine until we moved the board with its layout to a new situation. Everything still boots up ok but locos don't move upon command. 

Dumbo question: how can I check if power is reaching the track? Gently,  please,  I ain't the smartest with electronics