Installing red/green lights on layout

[pidge456]

Hi everyone, hope you are all well. I'm relatively new to all this technical stuff so have a question. I have a DCC set up using a select controller with 3 accessory decoders controlling the points (12 points in all). I find it a bit of a pain to know whether my points are in the right position for train movement so have to visually check the points position. I would like to add a simple red/green signal to each point eventually. I like the look of the traintech signals but they are rather expensive. Is it possible to connect a simple signal to the accessory decoder outlet of each point so that the signal will change when the point does. I have seen some signals which have three wires (red/green and black Everest JTD01 I think) can these just be connected to the decoder or is it not as simple as that.

Many thanks Andy.

[Flashbang]

Hi Andy

 

Unfortunately not quite as simple as connecting a signal or pair of LEDs to the output of the accessory decoder being used for point operation.  Reason is... The decoders output is  a momentary pulse of power to the point motor.. Lights/LEDs will need a continuous supply.  

IMO the simplest is to use a Gaugemaster GM500D connected to the three terminals of the decoder together with the point motor wires and then via the units relay contacts the signal aspects or LEDs are fed.

 

There was a topic here just recently about the same/similar thing...  http://www.hornby.com/uk-en/forum/adding-hornby-signal-lights-to-hornby-points-/?p=1

[Chrissaf]

Red Green Signals need an always 'ON' output. Your Solenoid points use a 'Pulse' output. Thus the two types of power requirements are not compatible with each other.

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Have a look at this previous post (look at the reply made by FlashBang) that suggests a GaugeMaster GM500D product to supplement the output of the Accessory Decoder. So that signals can be synchronised to point positions.

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https://www.hornby.com/uk-en/forum/adding-hornby-signal-lights-to-hornby-points-/?p=1

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In essence, the GM500D is a latching relay that converts the pulse output of the Accessory Decoder into an 'Always On' output to connect the signals to. Note: the signals will need their own dedicated low voltage DC power supply (typically 12 volts) wired to the GM500D to operate the signals. The signals should also include a current limiting resistor to protect the signal LEDs. The resistor is not required if using 'bulb' based signals, but then I would absolutely recommend using LEDs over bulbs every time. Bulbs require too much current, run too hot and have a much shorter lifespan compared to LEDs.

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See this GaugeMaster wiring diagram. My suggested 12 volt PSU is shown on the left. It is not clear whether the resistor to protect (current limit) the signal is included in the GM500D device or not**. Just because it is not shown on the diagram connected to the signals, don't assume that it is not needed. The GM500D can also do Electrofrog (Peco points) switching in addition to signals. The LED signal protection resistor if not part of the GM500D product would go in the black wire shown in the diagram between the signal and the power supply. The value would be typically 1,000 ohms.

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http://www.gaugemaster.com/instructions/gm500D.pdf

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 EDIT1: FB got in just ahead of me with the same answer.

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EDIT2 Note ** looking at the GM diagram and comparing it to the GM product photo it looks as if the relay contacts of the GM500D are just metallic contact paths and have no integrated protection resistors built in. The resistors that are shown in the product photo are part of the relay operating coil circuit (tracing the PCB tracks). Thus, my assessment would be that any protection resistors needed by the signals will need to be added to the signal / power supply circuit (one 1,000 ohm resistor per signal).

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EDIT3: Looking at the Everest JTD001 product description. The protective 1,000 ohm resistor for 12 volt DC operation is already pre-attached to the signal in the positive (common anode) supply wire.

 

[pidge456]

 Thanks guys I understand the problem now. Looks like the traintech signals may be the simplest option but unfortunately the most expensive.

[Chrissaf]

Looks like the traintech signals may be the simplest option

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I disagree...........the TrainTech signals need to be configured. They then have to be manually switched as an additional activity by your Select controller each time you change a point. You could automate this with RailMaster but you would need ProPack to link a signal to a point. Plus your Select controller is not supported by RailMaster.

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The GM500D is no more onerous to wire in to the accessory decoder than the signal itself, plus the signal operation is now automated and synchronised to the point position and doesn't need any manual operation. The only thing that is slightly more complicated is the need for a separate 12 volt supply to drive the signals.

[96RAF]

The requirement is - can I have red/green lights to indicate when my points have changed.

 

To achieve this the only sure way is for a switch operated by the mechanical action of the points changing to electrically signal a light/led to change colour to suit the selection.

 

Anything that acts in parallel with the selection is merely reporting that the selection was made, not confirming that the action completed.

 

There are several ways to achieve this switching, depending upon if you have basic solenoid point motors needing an add on switch or have solenoids with built in switches or have motor driven points actuators with built in switches.

[RDS]

... Anything that acts in parallel with the selection is merely reporting that the selection was made, not confirming that the action completed ...

 

Agreed.  I have Solenoid operated Point Motors and I feel it would be very easy to construct something, fastened to the bottom of the Solenoid that detects the movement of the Solenoid.  I feel it would have to be something like a light shone across and detected at the other side, with the light beam interupted by the Solenoid bar, rather than a microswitch than interfaces with the bar, that could disrupt the Solenoid movement.  

This may even lend itself to the Raspberry Pi Project I have been looking for!

[96RAF]

@RDS

I have always used the simple Peco PL13 slide switch either attached to the hefty 'normal' solenoids or modified to glue directly under a point when usin the smaller surface mounted solenoids.

 

I have tried those tiny microswitches but find them fiddly to setup as the spring arm can push the point of the set position.

[RDS]

@RAF96

I thought that the spring of a microswitch could in effect move the point from its set position and that is why I suggested the use of a light shone across and interrupted by the solenoid bar.  You can get devices that consist of a light at one side and a detector at the other, with a gap between.

I have one somewhere.  I will look it out and post a picture later.

Hopefully Chris(saf) will be along soon to suggest a suitable component!

[pidge456]

 I disagree...........the TrainTech signals need to be configured. They then have to be manually switched as an additional activity by your Select controller

 

 

Thanks for your comments. I thought that with the traintech signals all you did was program the signal to the same number as the point and then connect to the track??

[Chrissaf]

I thought that with the traintech signals all you did was program the signal to the same number as the point and then connect to the track??

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That should be possible in theory.

[RDS]

Further to my post at 9:50 on Tuesday, I have attached a picture of a sensor, similar to what I consider could be used to detect the solenoid bar on a Point Motor.  I removed this one from an old printer but I don't actually know the correct term for it to see if they are available commercially and in quantity./media/tinymce_upload/10212d96517c5c8f0a1e105a107c1b2b.JPG

[Chrissaf]

Search "Optical Proximity Sensor".

[RDS]

Thanks Chris, will do.

[RDS]

Thanks Chris, will do.

Actually, Optical Sensor gives better results but they seem to be too expensive to be worth using.

[Chrissaf]

Yes I noticed that too when I searched.....I was getting silly prices like up to £18 per unit. Although the average was somewhere between £3 and £8 each.

[RDS]

I was hoping for something like 99p for 10 off, (including postage) from China.  The cheapest I have seen so far has been £1.33.

[96RAF]

You could also look at hall effect sensors but these seem to work better with constant chops of the gap by a fan blade arrangement. They can be used to match chuffs when mounted to loco wheels so should be small and cheap.

whether they work by a single chop such as a solenoid pin with say a bit of tube attached for bulk sweeping past I dont know.

[RDS]

@RAF96

Actually, the way I envisage it is that the Solenoid Bar will not so much sweep past but stop at one end or the other and I am thinking that I would need 2 devices (whatever they are) for each point motor.  As far as I know, a Hall Effect Sensor, alters it's output voltage as it detects magnetism and maybe the Pin has picked up some magnetism by being constantly operated by a Solenoid, or maybe it could even be magnetised manually.  

Hall Effect Sensors are available quite cheap and in fact I have just ordered 5 off for 99p!

[Fozzy Bear]

I thought that with the traintech signals all you did was program the signal to the same number as the point and then connect to the track??

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That should be possible in theory.

Yep, it works fine. I bought one Traintech 2 aspect signal as a test and that was all I did. Way too expensive though so I got some el cheapo 12V automotive double throw relays from ebay, some 4 pole double throw relays and cheap 12V signals then made my own circuit. Using a separate 12V supply, I tested the scheme on the old layout by connecting it to the output of an R8247 which already have 2 point motors connected and it worked perfectly. 

The gaugemaster latching relay board that has been mentioned does exactly the same thing for about the same cost but without the fiddly wiring so I reckon they will be the way to go for the new layout.