Brixington Town 2.0

[dale159]

Further to my earlier post, here is a simplified diagram of what I've got so far for the scissors

 

So what remains to be connected are the straight ahead LEDs, I'd like the 4 of them to operate as 1.

 

As designed the points detection board has 16 outputs which work as 8 pairs, the scissors uses 4.

 

The LEDs are fed by a common 12v supply from the detector unit, each pair of LEDs earth to the detector unit which turns each input on or off as per the inputs from the switches.

 

What I need to work out is a way off suppressing all 4 straight ahead LEDs when either outputs 1 or 4 are set to 0 volts on the detector unit. As explained in this thread when I laid the track due to the way the scissors is wired I cannot throw both crossovers simultaneously and it is interlocked to prevent this.

 

I think the answer to the problem may lie in the use of some transistors, but I don't really know much about them.

 

Anyone electrically minded able to assist?

 

Dale

[Anthony566]

I was doing really well following this thread until the wiring started ... this is the very thing that gives me a head ache I am completely lost when it comes to electrics I have only just got to the point of setting up a few cobalt motors to test with.

 

Very impressive and very well done Dale.

[dale159]

So today I've been tidying up a few last little jobs that needed doing before I could put the layout back together for a test.

 

I have bought and installed the 2 CDUs required and wired in the 2 din sockets

 

3 transformers - left for points, middle for 12 volts DC and right for track feeds

 

And then the layout was reassembled followed by a bit of P-way work to the 2 damaged tracks and tweaking a few rail ends on the corners

 

Then the moment of truth

 

Using a handheld controller borrowed from the local club which happened to utilise the same pattern din plug.

 

Well the control panel lights up nicely, but there are one or two teething problems which need to be ironed out, chief among which is the fact I've managed to mix up the nine sections on the middle board - well the middle track is OK! I know exactly where I've gone wrong there so this will actually be quite easy to rectify.

 

The other major hiccup currently is that none of the points work despite lighting up the panel, not quite sure what's up there but I've had a multimeter on the transformer so I know that's working, and the track needs a damn good clean. A few things to be keeping me busy tomorrow then.

 

Dale

Edited March 12, 2015 by dale159

[dale159]

Another day out in the garage.

 

I soon sorted out the reversed section switches on the middle board plus the inner 2 roads around the corner on the left hand board. Although there are still a few dead sections and track joints which need attention as well as I'm yet to work out why the points don't work.

 

Another item which raised its head when I went to test the scissor crossing was a lack of power to the relays - I then discovered that this was because I had forgotten to connect the supply to the transformer - whooooops!

 

Also something which needs investigating is the Hornby transformer I'm using for the track supply, certain loco's predominantly Heljan run at barely a snails pace but it's not just Heljan items I've had such problems with.

 

Wonder what picture the felllows at General Electric had on the wall when they designed the 70!

 

Another oversight from the original build was what to do with the cable from anything plugged into the socket on the back wall

 

The solution - a small hook found in the box of screws - sorted!

 

Dale

[dale159]

This morning I have been visited by my friend Simon (Gilly of this parish) to see if 2 brains were better than 1 on some of my electrical issues.

 

He brought his trusty old H&M clipper with him which was first connected into the points supply however still no joy. Although it has confirmed that the Hornby transformers are not substantial enough for the job as his multimeter showed it was putting out just 14 volts and then mine said it was 16! The clipper was giving 18.5v AC

 

The clippers 18.5v AC was then connected to the track supply for the handheld controller, this was an improvement but still not perfect.

 

It was also uncovered why my Heljan 58 was running so slowly when we took the body off - it contained a Bachmann decoder which was unplugged in favour of a blanking plate and it ran much better.

 

So I now need to buy a pair beefier transformers and possibly sort out another handheld controller, Simon has also suggested bypassing the CDUs to see if I can persuade some life out of the point that way.

 

Dale 

[dale159]

I've been out in the garage this afternoon to have another tinker with the electrics.

 

I have managed to copse some life out of most of the points by bypassing the ribbon cables on the 3 common yellow wires between the 3 CDUs and the control panel as well as disconnecting the other ribbon type cables connectors to the scissor crossings, plugging these in kills the whole lot for reasons I've yet to establish, although I suspect the use of the ribbon cable itself may be the cause - to be investigated.

 

Other more minor issues include the LED displaying on the panel seem to flash randomly although I had disconnected a few wires while trying to diagnose the issues with the points, and a few points which fire in the opposite direction to the switch on the panel including 2 point which I'd manage to wire to the wrong switches - now rectified by swapping a few wires around.

 

Dale

[topsy11]

Hi Dale,

 

I can honestly say I feel your pain!

 

My layouts not quite as complex as yours but I'm having/had a bloody nightmate with my point motor's/indicator lights etc etc!

 

You seem a little more clued up than me at wiring and problem solving which certainly can't be a bad thing!

 

Keep at it mate!

 

All the best

Mark

[dale159]

Another quick trip out to the garage this morning to try another idea I had.

 

I wondered whether connecting the common feed to the points across 3 wires within the ribbon cable would word, thus spreading the load between them

As such, unfortunately no joy there, back to the drawing board

 

I also tried to see if I could get one of the scissors working by bypassing the long cables to it

A few jump leads later - but again no joy.

 

Although when all the wires were connected like this I found that unplugging the jump lead on the yellow wire caused the CDU to make a sound like the circuit was either being opened or closed - not sure which and that by only contacting one set of motors at a time the two interlocking motors under the panel would work, and that using the two feeds straight out the CDU and bypassing the control panel completely the motors on the scissors worked as tested when I built them. One other thing I did was loosen their screws by half a turn as I found this was stopping one other point elsewhere on the layout working.

 

Also the points on the other half of the lifting section don't work either for reasons I've yet to investigate but again could well just be that I screwed the motors in too tight.

 

I'm getting closer to a solution - honest!

 

Dale

[Memphis32]

Slightly painful suggestion, but it's what I'd do if I was troubleshooting it - rip out all the wiring, then reintroduce it one motor at a time, testing each motor as the wiring is installed. Then do the same with track power sections.

Edited March 7, 2015 by Memphis32

[dale159]

Good news!

 

Today I invited my friend Keith over in order to pick his brains on the points problems and between us we now have most of the points working without using jump leads. The problem it turns out was caused by me being a bloke and not reading the instructions for the point detection board in my haste to get the layout running. The detection board needs a feed from the CDU to work, however having read the instructions properly I needed to use the wire which was common to all the points whereas I had used the other output from the CDU which went to the common feed to the switches, being as that was the one which went into the control panel - easy error to make but as it turns out fairly critical!

 

There are a few other issues to look at - now updated

• Point motor for the two left hand side sidings is poorly mounted and does not throw far enough to energise the frog when reversed.
• 2 points on lifting section only fire one way - fault narrowed down to one connector between boards - Edit - fixed with higher voltage transformer
• Still no joy with the scissors, can't even get the interlocking boards under the control panel to work now - fixed with higher voltage transformer and moving the return wire to the right place
• Controller 1 has a short which seems to come and go randomly - Gone again not happened since I posted this.
• Most Pway issues now sorted most involving filing solder off the railheads.
• One dead section on the inside track along the back wall
• The Hornby Transformer was wired into the working points and was found to be not powerful enough for the job so has been removed pending a suitable replacement - Purchased, fitted and the Hornby one consigned to the bin

So, a few things to be keeping busy for a few weeks!

 

Dale

Edited March 19, 2015 by dale159

[dale159]

I think I've just worked out why my scissor crossings don't work!

 

Quite simply and for much the same reasons I was having problems with my point detectors is because I've wired the returns for the interlocking boards into the same yellow wire as it's being fed by - therefore not ccompleting the circuit.

 

Nothing 5 minutes with the soldering iron can't fix tomorrow afternoon! - What a plonker I've been!

[topsy11]

I'm glad you're solving it bit by bit mate!

 

Keep up the good work!

[dale159]

Another productive afternoon in the garage today.

 

261.jpg 262.jpg

The pair of Scissor interlock boards have been glued into place

 

263.jpg

And wired in.

Or at least I thought!

 

Well it turns out my Eureka moment in the early hours of this morning was spot on although unlike Archimedes I wasn't in the bath and I refrained from running naked down the street.

 

Here's what it looks like now.

 

So now the interlock boards work but unfortunately the scissors themselves still aren't firing but I suspect this is to do with a lack of ooomph out of the CDU due to the low voltage going into it, but that's from Simon's borrowed H&M Clipper.

 

So time for some online shopping to find a permanent transformer, and one for the track.

 

Dale

[dale159]

A quick video I've just uploaded to YouTube

 

 

Dale

[class"66"]

Looking rather good Dale

[Removed a/c]

We have movement ! and a nice loco it is too  

[dale159]

More good news.

 

Having ordered a new transformer, which was delivered today, I temporarily plumbed it in and gave it a go.

 

And the good news is the scissors reverse and the points at the left hand end also now work but the scissors won't reset on the push button, the interlock boards work but not the points on the layout so some further tinkering is required.

 

Dale

[dale159]

Just a thought on the scissors reset - I wonder if I put a resistor in the wire between the push button and the interlocking motors it would cause more current to flow to the motors on the points themselves. In theory the interlocking motors shouldn't need a huge amount of power as of course they are only used for their switches. Some experimentation to follow this afternoon I reckon.

 

Dale

[dale159]

Just a thought on the scissors reset - I wonder if I put a resistor in the wire between the push button and the interlocking motors it would cause more current to flow to the motors on the points themselves. In theory the interlocking motors shouldn't need a huge amount of power as of course they are only used for their switches. Some experimentation to follow this afternoon I reckon.

 

Dale

 

The 2 purple wires un-soldered from the copper tape and reconnected via the 1K resistor, current to the 4 scissor motors passes between the 2 purple wires as before.

 

Unfortunately testing showed mixed results - the motors under the scissors all now work off the push button but the interlock motors under the panel now don't! I think perhaps a lower resistance is required, I think I will try either a 470 or 680 and see what happens.

 

Dale

[dale159]

Well still no joy from the 680 or 470 resistors, got a few others I can try. Should the number be coming down or going up?

 

Dale

Edited March 17, 2015 by dale159

[dale159]

Another idea tried and proven not to work - wiring the interlock motors in series instead of parallel with the point motors (no resistors) but the voltage drop means I'm back to square 1 with just the interlock motors resetting. I'm wondering if there is some way I can run the interlock motors off the middle CDU in an attempt to spread the load required to reset but I haven't looked into how I might go about that and whether a feed from 1 CDU could earth into another one being as they are all powered by by the same transformer.

 

Dale

[Pete Harvey]

Why don't you use Automotive relays to operate as interlocks?

 

http://www.maplin.co.uk/p/12v-30a-dc-spdt-automotive-relay-n00aw

 

http://www.maplin.co.uk/p/12v-40a-dc-spno-automotive-relay-n02aw

 

http://www.maplin.co.uk/p/12v-40a-dc-relay-for-automotive-applications-ar32k

 

They are more reliable and there are more types than just the three I have posted the links for above.

 

Pete

[dale159]

Why don't you use Automotive relays to operate as interlocks?

 

http://www.maplin.co.uk/p/12v-30a-dc-spdt-automotive-relay-n00aw

 

http://www.maplin.co.uk/p/12v-40a-dc-spno-automotive-relay-n02aw

 

http://www.maplin.co.uk/p/12v-40a-dc-relay-for-automotive-applications-ar32k

 

They are more reliable and there are more types than just the three I have posted the links for above.

 

Pete

Thanks Pete.

 

I hadn't thought about doing that, I suspect that the interlock motors would work quite happily on 12v DC from a relay, I will have to get some scrap paper and start designing.

 

Dale

[dale159]

I have been designing a circuit diagram incorporating 3 car relays operating the interlock motors powered by the middle CDU

 

I think this will work, but a few more pair of eyes over it would be welcome

(On the relays as I have drawn them the input is directly opposite the output)

 

I can't quite see how using just the relays without the motors as Pete suggested will work given the pulse action of the Seep motors.

 

Dale

[Memphis32]

I'm still working on your led thing, but now thinking about this too. Can you clarify a few things please? What is supposed to happen when you try setting a crossover when the other one is set? Do all four motors fire to reset the other to normal, or does nothing happen unless you reset the crossover first? Also, can you tell me what model of detector board you're using to drive the LEDs?