Fulgurex point motor control

22521 Views 70 Replies 13 Participants Last post by dwb, Sep 15, 2009

dwb

Discussion Starter · Jan 8, 2007

This week's project is to add control circuitry for a Fulgurex slow motion point motor. The photo below shows the parts I intend to use:

Those familiar with driving Fulgurex will probably think this is a bit over the top, but there is method in my madness and each component has its place in my scheme.

First, it is my intention in the longer term to drive the point motor via DCC, but there may be times when I don't want to have to go to the bother of addressing the motor via the control unit and then selecting the direction I want. To avoid that, I need a local switch. Some DCC point motor controls provide a facility for local buttons, but I'm not sure which those are and whether or not I will use them. In the meantime, I need to control the motor now because unlike Peco solenoids, you can't manually "flick" a Fulgurex. My solution to this need is to use a normally open, momentary action DPDT switch which can be seen in the left of the photo.

The momentary nature of the switch means that once the limit has been reached and the current is switched off, I can release the switch and there will be no current at all. This should avoid conflicts with any DCC control unit I install later. The drawback with this method is that I lose the switch acting as an indicator for the current setting of the point blades. The solution to this problem is to use one set of auxiliary contacts on the Fulgurex to drive the pair of LEDs which are also on the left along with the resistors and matching mounting bezels. This will provide a visual indication by the switch of the current setting. When DCC control is added, any changes caused by the DCC unit will be reflected by the LEDs. This circuit may also double up as input to a pair feedback sensors to provide PC control some time in the distant future.

The ceramic disc capacitor at the bottom of the photo is to provide a degree of noise suppression. According to LDT, the Fulgurex is rather "noisy" electrically and this is a good precaution. Once the motor is installed under the baseboard, I don't fancy lying on my back trying to retrofit these things later, so they're going in now.

The other two devices beside the capacitor are a pair of Zener diodes. This again is an LDT recommendation for reducing the voltage supply to the motor to reduce the change over speed. I'm doing this because the motor will be supplied at about 14v DC which is a bit on the high side.

I will be using the other pair of microswitch contacts to change the frog polarity on the point. The switch blades themselves are hard wired to the outer rails. This eliminates the potential for shorts should the microswitch change over before the moving point blade has ceased making contact with the outer rail. A short on an analogue DC layout is no problem, but it will shut down DCC which is not a good thing.

The black stringy stuff in the top right is heat shrink tubing which I will use to make sure there are no bare wires straggling about.

Now I just need to find something to mount the switch and LEDs on. Panel thickness is a bit of an issue for these LED bezels because the LEDs are quite small.

David

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dwb

Discussion Starter · #6 · Jan 9, 2007

Thanks for the feedback.

>This leaves the voltage applied to the motors
I have chosen not to do this so that I don't get a conflict with a DCC accessory unit. The LDT unit is the top of my list at present.

>Is there any chance that you could produce a circuit diagram for how you will be using configuring this?
I really do need to do something so that I have a record. My memory tends to fade on the details after a few weeks.

David

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dwb

Discussion Starter · #7 · Jan 10, 2007

Circuit diagram:-

The completed assemblies - switch / LEDs; point motor. The light is on but there's nobody home.

I just need to decide on the control panel. Do I go for a full diagram or just a row of numbered switches and two rows of lights?

David

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dwb

Discussion Starter · #10 · Jan 11, 2007

Here's the section of the signal diagram for the first point to be motorised - it's the one at the top left corner.

In terms of panels, I was thinking of either a 2" high strip along the front edge of the baseboard with the switches mounted side by side, or maybe a 4" to 5" strip with a simple schematic.

When I worked out how many levers the station required and the distance to the furthest point (that's trackwork), I realised that the station is going to have a north box and a south box.

David

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dwb

Discussion Starter · #12 · Jan 12, 2007

>Which Staion is it David?
It's what will fit in a two foot by 24 foot length with 3 foot at each end taken up by the curves required to make a continuous run. So it's no particular station. The idea is to create the feeling of West Yorkshire in the 50s. I aired the original plan on the forum back in feb/march last year. Following some constructive criticism I dropped the platform count to two.

The current background is that this is a junction between a pair of LNWR and MR lines somewhere slightly east of Leeds. Both mainlines are double track with one line broadening to four lines to the right of the plan segment I have posted here.

Regarding photos, a couple of my blog entries give a flavour, but apart from some sections of retaining wall, there is no scenery to speak of but I do own a pack of Silflor grass tufts!

I want to get the track work established before going too far on the scenic side.

David

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dwb

Discussion Starter · #13 · Jan 18, 2007

In an effort to avoid actually doing any work and trying not to think of the horrendous consequences for my railway if the end gable fell off my house, I have drawn up this design for a control panel, for what I have decided will be the south end of the station. The idea is that it will fit (just) onto a 6" x ~19" aluminium panel of the type sold for 19" racking systems.

The area being controlled is about 10 feet long by 2 feet deep. The main feature of this end of the station is the diagonal ladder running from lower left to upper right which forms the exchange between the two main lines and exit from the goods / parcels depots. The slightly wider gaps to the left of the diagram are the two platforms which provide four faces for passenger trains.

The section shown at A is carriage sidings that will extend about 6 feet further but without any further points. The two lines at the bottom in section A are a double track mainline which in the initial plan will just be a return loop.

The four lines below A in the upper right of the panel are the main line to London. The line drops to double track as it leaves the station to the north.

The bottom 3 lines at the lower left are for receiving goods and parcels trains. The parcels depot is located under sub section "A" but contains no points. The goods yard is at the north end of the station and has a long receiving loop with a run around to allow the locomotive to be released.

David

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dwb

Discussion Starter · #16 · Jan 31, 2007

Now that I have the 3mm black lining tape from Halfords, I have been able to apply it to the aluminium panel to create the track diagram. This is what it looks like before I drill the holes:

The next job is drill holes for the toggle switches and LED bezels. I think I should get a drill stand and some clamps first. Do you think a "standard" DIY type job will be good enough?

David

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dwb

Discussion Starter · #21 · Feb 1, 2007

Thanks for the compliments and the tips. I will certainly act on them.

I did wonder about whether or not to lay the tape first, but it seemed the easiest way to "break into" the problem. I was making it up as a I went along using my original plan as a guide. I have a suspicion that the adhesive on the tape will "cure" over a period of a few days or so. If it does then, with a steady drill the damage will be restricted to the immediate area of the hole. The bezels on the switches and LED holders should cover any frayed edges.

If it all goes pear shaped then there is still plenty of tape left on the reel to do the whole lot over again once the holes are drilled.

David

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dwb

Discussion Starter · #22 · Feb 3, 2007

>I bought a Clarke's bench drill for about £35.
Would that be the CPD5DD? Machine mart are advertising them for about £35 or so.

Regarding drilling holes. I have no training in metalwork and precious little experience either, so I would greatly value some advice.

After I have donned safety specs and gloves(?) and secured the panel so that it won't move, how do I go about drilling the holes?

The panel is 3mm thick aluminium. The LED bezels need a hole in the region of 3mm and it is possible that the hole will have to be "relieved" at the back since the bezel is designed for 2mm max.

The switches require a hole at least 6mm, and there needs to be a wee "ding" on the top surface for the locking ring key which prevents the whole thing from twisting.

David

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dwb

Discussion Starter · #24 · Feb 3, 2007

Thank you for the advice John, it is much appreciated.

David

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dwb

Discussion Starter · #26 · Feb 4, 2007

Thanks MMaD

David

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dwb

Discussion Starter · #27 · Feb 22, 2007

A brief update...

boring, boring....

I didn't realise that there were quite so many holes.....

David

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dwb

Discussion Starter · #30 · Feb 23, 2007 (Edited by Moderator)

>While on the safety bit if you have any rings on your fingers take them off (if you can).
I don't think my wedding ring will come off. I don't have any other rings. I try to work with my left hand close to the off switch. I have the panel clamped to the drill platform with a piece of scrap wood underneath. Once it is secure, I operate the lowering handle with my right hand very slowly.

The only damage I've done to myself so far is a small scratch from the "safety" visor that you drop down in front before drilling. I keep my safety goggles on at all times.

>More pictures please smile.gif
I'll post a picture of the panel when I've drilled the holes for the switches.

The switches will be "in place" on the panel. I've chosen centre off double throw switches. All the leds will be red.

I'm tempted to add signal controls and section occupied indicators but with 32 points at 4 connections per point, I think I've reached saturation point for the panel size. Of course if I decided to stick to "pure DCC / computer" control the panel would be un-necessary..

David

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dwb

Discussion Starter · #31 · Feb 24, 2007

The drilling has finished. I have "loaded" the panel with four switches and 8 LEDs. Here's what it looks like from the front:-

and here's the view from the back:-

I made the support brackets from "L" shape and plain aluminium strip I bought from B&Q.

Now I have to decide whether to drill any more holes "just in case" because once I start wiring it, that's it. The likely candidates are some LEDs to indicate section occupancy and some activation switches for electric uncouplers.

While I am pondering that, I'm going to work out how to arrange the rather large number of wires in a neat and orderly fashion

David

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dwb

Discussion Starter · #33 · Feb 24, 2007

>I used a plastic spiral round
That's a good idea; I remember using it years ago at work.

David

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dwb

Discussion Starter · #35 · Feb 24, 2007

>That's looking very good David, very professional.
Thank you. It wouldn't pass close inspection though; some of the holes have wandered by up to 2mm.

David

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dwb

Discussion Starter · #36 · Feb 24, 2007

>very professional.
I should also mention that most of the appearance is due to advice given in this thread - I bought a Clarke drill press and an automatic centre punch to mark the position of the holes.

David

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dwb

Discussion Starter · #37 · Feb 24, 2007

I think I might drill a set of holes along some sections for some LEDs (maybe yellow) to indicate "section occupied". I think the Lenz LB101 module might be just the thing to drive this as it is a current sensor which delivers some kind of output when 1ma is detected flowing in the DCC supply. The only thing I don't know is, what kind of output is being delivered? It would be nice to know what volts and amps are involved. Does anyone know?

David

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dwb

Discussion Starter · #38 · Mar 4, 2007

I have drilled a set of holes which can be used as section occupancy indicators. I have also added four more switch holes and LED holes offset to the north east of the switch hole. These will be for electrically operated Kadee uncouplers. One side of the two pole switch will activate the relay which will allow the 3 amps needed by these brutes to operate. The other will send current through the indicator LED at the top left to show that the circuit is operating. I rather fancy blue for that.

Here's the state of the panel with the extra holes and most of the dirt cleaned off:

I have now started the process of installing the LED bezels, but I have run out.. I think I need another 100.

David

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dwb

Discussion Starter · #40 · Mar 4, 2007

>it's going to look really good when lit up.

The whole country will know because of the "brown out" when I switch it on

David

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