[dwb]

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

 

[Peter_Harvey]

What you are doing there is very interesting at present I'm using peco point motors through a independant cdu so theat dose not interfere with my DCC but I'm planing to move to an all in one unit in the future, so this will be usfull then whatever point changing system I decide to use.

Pete

 

[Doug]

I'm playing with the same concepts.

I have just come into possession of 4 control panel covers made from aluminium. About 2mm thick which is fine for the LED bezels.

I also like the local switching idea. Even though I've been switching using DCC, I think I prefer a local control panel with a simple control diagram. I will have 3 or 4 panels around the layout.

 

[John Webb]

Dear David,
I have also used Fulgerex motors. I work these from a +12-0-12V supply via a change-over switch. This leaves the voltage applied to the motors which can be used via the unused tab on the limit switch each end of the motor to feed back to an LED showing which way the point is set. So the auxilary switches are left free for other functions, such as interlocking with signals.
Regards,
John Webb

 

[Peter_Harvey]

David

Is there any chance that you could produce a circuit diagram for how you will be using configuring this?

Pete

 

[dwb]

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

 

[dwb]

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

 

[Makemineadouble]

No more control panels for me in future I'm going the American method just install your turnout control on the facial with a simple diagram. It easier, no complex carpentry, and panels to walk into.

 

[Peter_Harvey]

Thanks David most interesting.

Pete

 

[dwb]

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

 

[Peter_Harvey]

Which Staion is it David?

Any pictures of the railway so far?

Pete

 

[dwb]

>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

 

[dwb]

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

 

[Colombo]

Using Fulgurex point motors, or the very similar Lemaco type, with a diode matrix, it is possible to set up routes using a rotary switch. This does away with the need to set each individual point and is very useful for setting routes into storage sidings.

The club layout at the Clay Cross Model Railway Society has an array of 18 roads in the storage sidings, nine in each direction. Each one is long enough to hold two medium length trains, or one full length train. It is only necessary to control the points at the entry to the loops. At the exit from the loops the points blades are not fixed, they are sprung and the train just pushes through. No special wiring is needed to arrange this.

So how does the diode matrix work? The operator simply turns the rotary switch, to road 4, for example. A supply of 16v AC is fed into the rotary switch. Contact no. 4 on the rotary switch is connected into all the point motors driving the array of eight points via a diode for each one which sends positive or negative half wave rectified power to set them in the right direction. Normally it is only necessary to change to the next adjacent track as we run trains in sequence, and so usually only one or two points are changed at a time.

This is a good way to run an exhibition layout as we never need to make a physical check that all the points have been set correctly.

Colombo

 

[Colombo]

For the purposes of clarification, I should like to add to the previous posting that each contact on the rotary switch is only connected to those points that you have to set to access that particular loop. For a set of nine storage loops the minimum number of diodes for a symmetrical arrangement would be three per contact, or 27 in total: the maximum for a ladder arrangement would be 45.

Colombo

 

[dwb]

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

 

[Brian]

Dave
Nice looking facia.

Wondering..... Should the panel switch & any indication light holes be drilled before the tape is laid?

Thoughts of carefully laid tape ripping away from the surface and tearing as the drilling starts springs to my mind!

Easy to drill a hole on the pencil line then tape over and cut tape around hole!

 

[Colombo]

David,

Nice looking panel.

I used to cut out a section of the tape equal to the diameter of the hole that I wanted to drill. Then I would use a punch to start the hole before drilling, otherwise the drill tip could wander about.

Colombo

 

[John Webb]

Dear David,
I agree with Columbo - use a centre punch to mark the hole. I also tend to use a 1 to 3mm drill to make an initial hole before drilling out the hole to the final required size.

Re a drill stand - I bought a Clarke's bench drill for about £35. This has an adjustable belt drive for different speeds for different size drills. It gives much better control when drilling than a hand-held drill, and I have found it very useful.

Regards,
John Webb

 

[Colombo]

David,

I agree: get a proper drill stand if you have somewhere to mount it. You will never regret it. I have been able to fabricate all sorts of things since I got mine years ago. I can buy steel offcuts, angle iron and the like, out of the bin at the local steel stock yard quite cheaply.

Engineering could take over from modelling.

Colombo