R8247 and signals

[Den999]

Hi everyone i am new to train and layouts and already have made some critical errors. 

I now have a fairly stable Fleischmann N gauge DCC layout with a separate 12v bus power supply for the street lamps, cars, houses and station lights. And Hornby R8247 point controller serving my 4 Fleischmann turnouts  all workin very well. What I would like to add is a Dapol 2l-001-001 signal to one of my points. What I thought I would do is connect the signal power to the 12v bus and connect the signal control to the same point controller I want signal controlled. Sounds too easy after the problems I have had. All school errors.

can anyone help me please.

kind regards

Den

[Chrissaf]

The Dapol web site does not seem to publish any user guides for their products, so I have not been able to fully research your issue. From the minimal amount of information I have gleamed from the Dapol product pages I have deduced that the Dapol 21-001-001 is not compatible with the Hornby R8247 as it uses a completely different control system. Apart from which, you have already stated that all four ports on your current R8247 are being used to control points.

.

As a matter of principle, electronic circuits require current return paths. It is not electronically practicable to connect a device to a 12 volt power supply (the Dapol website infers the power supply required to be 16 volts AC anyway) and then control it from a completely different power source (i.e the R8247) without at least one of the supply rails being common to both power sources. What you are asking to do is just not electrically viable without a custom made interface.

.

The Dapol website gives a solution for controlling your Dapol 21-001-001 signal(s) via DCC it is their 4A-001-001 DCC signal decoder. If you are using RailMaster you can link the point and the signal together in the software so that they operate together in a synchronised fashion. Reading between the lines of your posted question it is this synchronisation that is key to what you are trying to achieve. According to the Dapol website the 4-001-001 DCC decoder has been developed for Dapol by TrainTech and loosely based on TT DCC decoder technology used in their own range of signal products.

.

If the Dapol 21-001-001 instructions could be posted in this thread, then possibly some alternative control options could be derived from them. A switch added to your point for example might be suitable to operate your signal.

[Den999]

The Dapol web site does not seem to publish any user guides for their products, so I have not been able to fully research your issue. From the minimal amount of information I have gleamed from the Dapol product pages I have deduced that the Dapol 21-001-001 is not compatible with the Hornby R8247 as it uses a completely different control system. Apart from which, you have already stated that all four ports on your current R8247 are being used to control points.

.

As a matter of principle, electronic circuits require current return paths. It is not electronically practicable to connect a device to a 12 volt power supply (the Dapol website infers the power supply required to be 16 volts AC anyway) and then control it from a completely different power source (i.e the R8247) without at least one of the supply rails being common to both power sources. What you are asking to do is just not electrically viable without a custom made interface.

.

The Dapol website gives a solution for controlling your Dapol 21-001-001 signal(s) via DCC it is their 4A-001-001 DCC signal decoder. If you are using RailMaster you can link the point and the signal together in the software so that they operate together in a synchronised fashion. Reading between the lines of your posted question it is this synchronisation that is key to what you are trying to achieve. According to the Dapol website the 4-001-001 DCC decoder has been developed for Dapol by TrainTech and loosely based on TT DCC decoder technology used in their own range of signal products.

.

If the Dapol 21-001-001 instructions could be posted in this thread, then possibly some alternative control options could be derived from them. A switch added to your point for example might be suitable to operate your signal.

Hi Chrissaf, thanks for the speedy reply. So if I have this correct  I can install the Dapol signal controller on my Layout. I would then have to control the signal independently of the turnout. I.E switch the signal the  switch he point. A signal and a point cannot share the same port on the point controller. 

 

Regards

Den

 

[Den999]

The Dapol web site does not seem to publish any user guides for their products, so I have not been able to fully research your issue. From the minimal amount of information I have gleamed from the Dapol product pages I have deduced that the Dapol 21-001-001 is not compatible with the Hornby R8247 as it uses a completely different control system. Apart from which, you have already stated that all four ports on your current R8247 are being used to control points.

.

As a matter of principle, electronic circuits require current return paths. It is not electronically practicable to connect a device to a 12 volt power supply (the Dapol website infers the power supply required to be 16 volts AC anyway) and then control it from a completely different power source (i.e the R8247) without at least one of the supply rails being common to both power sources. What you are asking to do is just not electrically viable without a custom made interface.

.

The Dapol website gives a solution for controlling your Dapol 21-001-001 signal(s) via DCC it is their 4A-001-001 DCC signal decoder. If you are using RailMaster you can link the point and the signal together in the software so that they operate together in a synchronised fashion. Reading between the lines of your posted question it is this synchronisation that is key to what you are trying to achieve. According to the Dapol website the 4-001-001 DCC decoder has been developed for Dapol by TrainTech and loosely based on TT DCC decoder technology used in their own range of signal products.

.

If the Dapol 21-001-001 instructions could be posted in this thread, then possibly some alternative control options could be derived from them. A switch added to your point for example might be suitable to operate your signal.

Hi Chrissaf, thanks for the speedy reply. So if I have this correct  I can install the Dapol signal controller on my Layout. I would then have to control the signal independently of the turnout. I.E switch the signal the  switch he point. A signal and a point cannot share the same port on the point controller. 

 

Regards

Den

 

[Den999]

The Dapol web site does not seem to publish any user guides for their products, so I have not been able to fully research your issue. From the minimal amount of information I have gleamed from the Dapol product pages I have deduced that the Dapol 21-001-001 is not compatible with the Hornby R8247 as it uses a completely different control system. Apart from which, you have already stated that all four ports on your current R8247 are being used to control points.

.

As a matter of principle, electronic circuits require current return paths. It is not electronically practicable to connect a device to a 12 volt power supply (the Dapol website infers the power supply required to be 16 volts AC anyway) and then control it from a completely different power source (i.e the R8247) without at least one of the supply rails being common to both power sources. What you are asking to do is just not electrically viable without a custom made interface.

.

The Dapol website gives a solution for controlling your Dapol 21-001-001 signal(s) via DCC it is their 4A-001-001 DCC signal decoder. If you are using RailMaster you can link the point and the signal together in the software so that they operate together in a synchronised fashion. Reading between the lines of your posted question it is this synchronisation that is key to what you are trying to achieve. According to the Dapol website the 4-001-001 DCC decoder has been developed for Dapol by TrainTech and loosely based on TT DCC decoder technology used in their own range of signal products.

.

If the Dapol 21-001-001 instructions could be posted in this thread, then possibly some alternative control options could be derived from them. A switch added to your point for example might be suitable to operate your signal.

Hi Chrissaf, thanks for the speedy reply. So if I have this correct  I can install the Dapol signal controller on my Layout. I would then have to control the signal independently of the turnout. I.E switch the signal the  switch he point. A signal and a point cannot share the same port on the point controller. 

 

Regards

Den

 

[Chrissaf]

Den,

Can I suggest that you do not use the 'Blue Quote Arrow' embedded in the text box when you want to reply. Just scroll down to the large great big empty reply text box at the bottom of the page. Put your reply text in there and click the 'Green' Reply button. Just as I have done in posting this very reply.

.

Not only that, but because you have clicked the save button multiple times you have duplicated all my previous text (using the Blue Arrow) multiple times as well. You have probably now used up your 3 posts a day newbie limitation (introduced to overcome auto-bot spammers that were flooding this forum with rubbish duplicated posts). So you may find that you can not post back here again before tomorrow.

.

In answer to your question. I have already answered your question in my first reply, so I repeat my answer again.

.

If you have RailMaster, then you can have a point linked to a signal and control both together. But you would need Dapol's purpose made DCC decoder that I gave a link for to make this happen.

.

If you do not have RailMaster, then subject to you posting the Dapol signal instructions into this thread for us to examine then it MIGHT be possible to synchronise the point and signal together via a physical switch fixed to the point in question. If this is not an option, then you will still need the Dapol DCC decoder and then you would have to operate the point and the signal independently of one another as they would have two different DCC addresses.

.

What you can't do is wire your Dapol signal directly to the R8247 port you are using to control the point. The Dapol signal includes an electronic control circuit board within it and it looks (based on what minimalist information is on the Dapol website) like it needs an external remote push switch to operate it. This does not make it realistically compatible with the R8247, and also not compatible for the electrical reasons I gave in my original reply regarding electrical current return paths. The Dapol signal needs its own dedicated supply to function plus a control wire. You stated 12 volts DC, but the Dapol site infers 16 volts AC. Another reason for us here to have visibility of the Dapol instruction sheet (as it is not a Hornby product) to make an informed valid judgement on its capabilities and limitations in a Hornby environment.

.

If you could scan your instructions into your PC and post them back into this thread as an image, then that would help us to help you with further alternative suggestions. Note: if you post an image, it will not appear in this thread straight away. It has to be checked and passed by admin before it is published, this can take a couple of minutes or more than 24 hours. It just depends what time of the day and day of the week you post it, excluding weekends that might take longer.

[Chrissaf]

Just for further clarity.

.

The "Dapol 4A-001-001DCC Signal Controller" performs a similar function to the Hornby R8247 Accessory Decoder but specifically for Dapol Signal products. The Dapol 4A controller can't do points, only Dapol Signals.

.

The Dapol 4A is a 'self learning' decoder that needs minimal configuration actions to set it up. You press the physical 'Learn' button on the Dapol 4A unit. You send an operate command from your DCC controller using the DCC addresses that you want to configure the signal with. The Dapol 4A 'Learns' this address by reading the digital DCC command sent to it. Job done.

.

The Dapol 4A connects to your DCC track power, not the aux 12 volts power supply that you are using, as it needs to see the DCC digital commands being issued by your controller (you still haven't told us which DCC Controller you are using.....it would be really helpful if you would. Also what point motor are you using? - to research whether a suitable electrical switch is available for it).

.

I suspect when using the Dapol 4A controller that the Dapol Signal product (N Guage Semaphore Signal) only connects to the Dapol 4A controller and does not need a separate connection from the Dapol Signal to your 12 volt supply. But again, there are no downloadable user guides of the Dapol 4A controller on the Dapol web site to confirm this.

.

 

 

[Chrissaf]

Found a Dapol Semaphore signal video on YouTube that has answered some of the question left open by the lack of Dapol website downloadable product instruction sheets. The one featured in the video had four wires, two for a 16 volts AC supply and two to connect to a momentary action push switch. Press once to raise the Semaphore and again to lower it. .

.

The nature of the Dapol Signal requiring a metallic momentary push switch action makes it incompatible with the output of the R8247 without a custom interface circuit. Something like a pair of miniature relays each with their make contacts in parallel. You can't use a latching relay because the make contacts of the relay need to be momentary in action. You would need two relays, such that the point switching in the other direction restores the previous semaphore signal position. You couldn't use a physical switch attached to a point, as the contact action needs to be momentary, not always on (nor the change-over action that these type of switches provide).

.

A lot of extra expense and wiring complexity. It may also be that putting the coils of the relays across the coils of the existing point motors (thus sharing the same R8247 port as you have requested) MAY adversely affect the operation of the points or what is more likely the relays won't function at all due to the mismatch in the relay / point coil resistances. The very low resistance of the point solenoid coils (typically about 4-6 ohms) is very nearly a 'short circuit' across the significantly higher resistance of any relay coil in parallel with it. Thus in all likelihood the relay will be starved of sufficient current to operate it. All the available current will route into the much lower resistance point solenoid coils.

.

In my view, either control the Signal manually with the push button it is designed to be controlled by, or use Dapols own 4A Signal Controller decoder for control via DCC.

.

As I have said twice before, if you have RailMaster, you can configure a point when operated to set an associated signal at the same time all under DCC control.

.

If you connect the two yellow wires of the dapol Signal directly to the output of the R8247. Apart from not being a viable working solution. You risk damaging the Dapol Signal electronics or the R8247 or both.

[Gearoid]

 Hi Den,

I have managed to get a Dapol signal working on my layout using a relay switch and a connection to an R8247, take a look at this youtube video from:

The wiring was very easy, but you need Railmaster Pro to synchronise the point change with the signal change. It must have an independent connection to thr R8247, it wont work if you use the same connections on the R8247 that the point is connected to. Best of Luck

[choralc]

Even I understood that procedure in the Simon's Shed video.

[96RAF]

The other option is 2 separate acc decoders on the same address, one for the point motor and the other for the relay that operates the signal. This shares the load and allows port config of one decoder to pulse and the other decoder to continuous output.

[Chrissaf]

It is fairly obvious that Simon in Simon's Shed has no understanding of basic electrical theory. In his video he states:

.

'it doesn't work when connecting the signal relay to the same accessory decoder (AD) port as the points, but he didn't know why'.

.

It was obvious to me, and staring me in the face. His signal solution was to use a single relay and join the + & - outputs of the AD together to feed into it. Joining these two terminals together would if connected to the same AD port as point motors provide a short between the inputs of both point switching coils. Thus when you try to throw the point, both coils get equally energised and cancel out, thus no movement of the solenoid iron operating bar.

.

OK, you could get over the short issue by including two diodes in the + & - feed wires just before they join together, such that currents do not get fed back into the other wiring leg. But even if you did that, it doesn't overcome the parallel path resistance mis-match of putting a solenoid coil of less than 10 ohms in parallel with a relay coil of about 1,000 ohms. Current takes the path of least resistance.

.

I've lost count of the number of these YouTube videos I've watched providing electrical wiring solutions to different issues. OK, they work, but more due to luck than judgement, but always portrayed by the presenter as this IS the solution and ONLY solution.

.

Anyway rant over.......having a go at YouTube presenters who haven't got a clue by the way.........not anybody here.

.

PS - I would include the two diodes I mentioned, in the Simon Shed wiring solution if using a single relay, if only to provide additional protection to the AD. It can't be good practice to purposely 'short circuit' the + & - outputs of the AD.

.

Note for information: The band (typically white on a black background) printed on the diode (suggest a generic 1N4001) should face towards the + and - terminals. The other end of the diodes should face towards the joint (made in Simon Sheds video) of the Red & Black wires