Dock Green

[chaz]

I took a break today from the FVRR to sort out the problem with the internal (infernal?) switches of my Tortoises that keep letting me down. I am using relays to do the trick, have a look at....

 

http://www.rmweb.co.uk/community/index.php?/topic/119945-tortoise-remedy-an-alternative/

 

...for deets! Or you could scan this topic as I think I did cover this earlier. At the last show we did we had a problem with yet another crossing going dead so I decided it was time to bite the bullet and sort out the remaining points.

 

Chaz

Edited February 14, 2017 by chaz

[Simond]

Chaz,

 

Good to see you're still posting on DG.

 

I've never had an issue with Tortoise switches, I think the relay solution is elegant, and will certainly work well.

 

An alternative that might offer some extra possibilities would be to use multi-pole relays, these are available from the usual sources, including Maplin, Rs, Farnell, etc., and would allow interlocking, signal operation & so on.

 

Best

Simon

[chaz]

Chaz,

 

Good to see you're still posting on DG.

 

I've never had an issue with Tortoise switches, I think the relay solution is elegant, and will certainly work well.

 

An alternative that might offer some extra possibilities would be to use multi-pole relays, these are available from the usual sources, including Maplin, Rs, Farnell, etc., and would allow interlocking, signal operation & so on.

 

Best

Simon

 

Thanks Simon. There will still be the occasional DG posting from time to time.

 

Yes, you could certainly use multi-pole relays if you have need for more switches. In fact you could this to increase the number of switches even if there is no need to replace the Tortoise ones.

 

Chaz

[Simond]

Indeed.

 

If the tortoise is working properly, and you're using DCC, you can use the frog polarity to trigger the relay - I suggested such a scheme to Rod for his West Kirby layout.

 

On reflection, using the diode appears to be a simpler approach - I'll link this to his thread

 

Thanks

Simon

[chaz]

Indeed.

 

If the tortoise is working properly, and you're using DCC, you can use the frog polarity to trigger the relay - I suggested such a scheme to Rod for his West Kirby layout.

 

On reflection, using the diode appears to be a simpler approach - I'll link this to his thread

 

Thanks

Simon

 

I did use crossing polarity to light indicator LEDs on a layout that had a couple of points that were out of sight from the panel - however you do have to be careful doing this - I did encounter some odd backfeeds that I never got to the bottom of which would cause the LEDs to light very dimly when they should have been off.

 

My Tortoises on Dock Green are switched with DPCO on two small panels so the only DCC connections that went to them were the crossing wiring, but that's now been re-routed to relays.

 

Chaz

Edited February 15, 2017 by chaz

[douglas clark]

chaz,

 

As someone new to the hobby, with pretty limited space, but wants to model at 7mm scale and wants to tell a story, I frankly have found this thread inspirational. What you did there, from start to finish is pretty well amazing.

 

Going to start a Jim McGeown kit in a wee while. My first attempt at this!

[chaz]

chaz,

 

As someone new to the hobby, with pretty limited space, but wants to model at 7mm scale and wants to tell a story, I frankly have found this thread inspirational. What you did there, from start to finish is pretty well amazing.

 

Going to start a Jim McGeown kit in a wee while. My first attempt at this!

 

Thanks for the positive comment Douglas.

 

Which kit are you starting with?

 

Chaz

[chaz]

All the points on Dock Green have now got their crossings switched by relays rather than rely on the internal switches in the Tortoises. This should mean an end to the "one at every show" irritant of a crossing going dead for one or both routes, causing certain locos to stall. Over four years and maybe fifteen shows Peter and I have slowly refined the operating side of the layout to eliminate most of the bugs. The only thing we will never eradicate is operator error - Murphy's law must still have some way of spoiling things.

 

Our next show is the Salisbury one (actually in Wilton) on the 13th and 14th May. See you there?

 

Chaz

[Donw]

All the points on Dock Green have now got their crossings switched by relays rather than rely on the internal switches in the Tortoises. This should mean an end to the "one at every show" irritant of a crossing going dead for one or both routes, causing certain locos to stall. Over four years and maybe fifteen shows Peter and I have slowly refined the operating side of the layout to eliminate most of the bugs. The only thing we will never eradicate is operator error - Murphy's law must still have some way of spoiling things.

 

Our next show is the Salisbury one (actually in Wilton) on the 13th and 14th May. See you there?

 

Chaz

 

100% reliability 100% of the time is probably too much to hope for. I suspect the relays will be fairly reliable. Is the failure rate of the Tortoise switches affected by the setting of the fulcrum. I usually try to ensure a good amount of movement of the operating arm . The best way to arrange LED displays I found was to use half wave either pos or neg pulses to drive the tortoise and put a bi-polar led in the feed set so a green light was normal and a red reversed worked well for me. I am looking to try servos for signals but you are back to needing a polarity switch. I know you can use Frog Juicers with DCC but that would mean you could use DC on the layout even for testing. It so much easier with the live steam in the garden.

Don

[chaz]

100% reliability 100% of the time is probably too much to hope for. I suspect the relays will be fairly reliable. Is the failure rate of the Tortoise switches affected by the setting of the fulcrum. I usually try to ensure a good amount of movement of the operating arm . The best way to arrange LED displays I found was to use half wave either pos or neg pulses to drive the tortoise and put a bi-polar led in the feed set so a green light was normal and a red reversed worked well for me. I am looking to try servos for signals but you are back to needing a polarity switch. I know you can use Frog Juicers with DCC but that would mean you could use DC on the layout even for testing. It so much easier with the live steam in the garden.

Don

 

I have no doubt the relays will be very reliable - I have never known one to fail. All those on Dock Green are new but even the 2nd hand ones that were ex-equipment that I have had in long-term use in the past proved very reliable.

 

"Is the failure rate of the Tortoise switches affected by the setting of the fulcrum?" I don't know Don. It could be but I wasn't prepared to spend time trying to solve the problem by adjustment - which might have proved fruitless - when for a little extra time and money it was solved.

 

The use of servos need not be a problem. The MERG servo driver boards work by switching a single output high or low (working as an on/off) and the servos respond to this. The same output line could be used to switch a relay. If this signal line will not drive a relay (too low a current - but I don't know if this is so or not) then a driver transistor would solve the problem.

 

I have always thought that frog-juicers were a complicated (and expensive) solution to the problem, but I do conceed that they simplify the wiring required.

 

Chaz

[Donw]

I have no doubt the relays will be very reliable - I have never known one to fail. All those on Dock Green are new but even the 2nd hand ones that were ex-equipment that I have had in long-term use in the past proved very reliable.

 

"Is the failure rate of the Tortoise switches affected by the setting of the fulcrum?" I don't know Don. It could be but I wasn't prepared to spend time trying to solve the problem by adjustment - which might have proved fruitless - when for a little extra time and money it was solved.

 

The use of servos need not be a problem. The MERG servo driver boards work by switching a single output high or low (working as an on/off) and the servos respond to this. The same output line could be used to switch a relay. If this signal line will not drive a relay (too low a current - but I don't know if this is so or not) then a driver transistor would solve the problem.

 

I have always thought that frog-juicers were a complicated (and expensive) solution to the problem, but I do conceed that they simplify the wiring required.

 

Chaz

 

my choice of servo driver is the Megapoint one it includes a lovely random bounce option for signals  each board controls up to 12 servos. Dave who designed the stuff recommends using a microswitch I might ask him about the use of a relay.

Don

[chaz]

my choice of servo driver is the Megapoint one it includes a lovely random bounce option for signals  each board controls up to 12 servos. Dave who designed the stuff recommends using a microswitch I might ask him about the use of a relay.

Don

 

Microswitches should be just as reliable as relays (as they are industrial standard devices) - providing the arrangement to operate them is robust and accurate. I didn't use them on Dock Green as I didn't want the work involved in fixing nine of them to the outside of the Tortoises. The wiring of a relay and diode is easier and could be done without the need to remove the Tortoises.

 

Chaz

Edited April 2, 2017 by chaz

[3 link]

Morning Chaz,

 

I have Started installing some tortoise motors on the fiddle yard part of my layout and out of the six, I have had problems with just the one.

 

I also would like to make them as reliable as possible, so is there a chance you could put up a diagram or photo of how you incorporate the relays, I am a total numpty with anything to do with electronics so it would be most appreciated.

 

Regards,

 

Martyn.

[Donw]

Microswitches should be just as reliable as relays (as they are industrial standard devices) - providing the arrangement to operate them is robust and accurate. I didn't use them on Dock Green as I didn't want the work involved in fixing nine of them to the outside of the Tortoises. The wiring of a relay and diode is easier and could be done without the need to remove the Tortoises.

 

Chaz

 

It wasn't the reliability of the microswitch that concerned me more the reliability of whatever linkage I used to operate it. Using the relay there would be no need to have any linkage other than wiring and the relay can be placed wherever most convenient.

Don

[toplink@()1989))((]

Morning Chaz,

 

I have Started installing some tortoise motors on the fiddle yard part of my layout and out of the six, I have had problems with just the one.

 

I also would like to make them as reliable as possible, so is there a chance you could put up a diagram or photo of how you incorporate the relays, I am a total numpty with anything to do with electronics so it would be most appreciated.

 

Regards,

 

Martyn.

 

There is an article in MRJ describing how the author went about just this conversion, it was in one of the latest issues, if I can find it, (I am very untidy) I will let you know the issue number.

 

 

Pete.

[toplink@()1989))((]

Found it, number 252 January ish'.

 

Pete.

[chaz]

Morning Chaz,

 

I have Started installing some tortoise motors on the fiddle yard part of my layout and out of the six, I have had problems with just the one.

 

I also would like to make them as reliable as possible, so is there a chance you could put up a diagram or photo of how you incorporate the relays, I am a total numpty with anything to do with electronics so it would be most appreciated.

 

Regards,

 

Martyn.

 

The wiring is very simple Martyn, here's a quick sketch...

 

 

a few notes

 

• the diode can be a simple signal diode - 1N4001 would a good one - it makes the relay only come on for one setting of the DPCO switch
• any relay with the correct voltage rating (whatever voltage you are running your Tortoises at) and an internal switch with a pair of change-over contacts
• when I do this I can't be bothered to work out which way round to wire the feed wires. I put temporary connections to my DCC bus and then use a continuity tester to check whether the crossing is correctly polarised - 50% chance of being right.

Hope that helps!

 

Chaz

[chaz]

Found it, number 252 January ish'.

 

Pete.

 

Pete, as I recall the solution in MRJ was to fit a microswitch. Just as good as my method but it does need the Tortoise(s) to be dismounted and dismantled. If you use a relay there is no need to do that - just a few wires to be added or re-routed. You pays your money....

 

Chaz

[Simond]

If I had an issue with my tortoises, which, to date I haven't, I'd go with Chaz' method.

 

Best

Simon

[3 link]

Thanks Chaz,

 

So basically you can buy these relays already fitted with a internal switch, sounds good to me.

 

Cheers,

 

Martyn.

[chaz]

Thanks Chaz,

 

So basically you can buy these relays already fitted with a internal switch, sounds good to me.

 

Cheers,

 

Martyn.

 

Yes Martyn. A relay is a switch, but there is no button or toggle, there is a coil, which acts as an electromagnet and which is connected mechanically to the internal switch contacts. The switch is thrown by passing a current through the coil. There is also a spring which throws the switch back when the current stops. Some relays have more than one switch inside, four separate switches are not unusual, which can be very useful for some layout wiring schemes.

 

Relays can very useful for keeping different types of circuit apart - there may be a relay in your car connected to the horn. So the switch that you press to sound the horn works on a low current, and is protected from damage by the higher current that the horn will draw.

 

Do a "google" to find out more about relays?

 

lecture over - sorry I can't help it - I used to teach technology

 

Chaz

Edited April 3, 2017 by chaz

[3 link]

Evening Chaz,

 

This particular relay sounds about right, would you agree? Sorry for all the questions.

 

Martyn.

 

 

12v-dc-2a-spdt-miniature-relay

12V DC 2A SPDT Miniature Relay

Code: N90ED

Suits various circuits in the modelling and hobby markets

Pin terminals for easily soldered joints

2A switching capacity

£2.99

 

Home Delivery Click & Collect

Find in store

Product details

• Suits various circuits in the modelling and hobby markets

• Pin terminals for easily soldered joints

• 2A switching capacity

• Designed for operation on a 12V DC power source

• Single pole double throw

 

Why use a standard relay?

This relay is perfect for use in home automation, modelling applications or hobbies. The relay can be mounted onto a PCB board, and comes with eight easily soldered pins. Its compact size means the relay can fit into a wide range of projects and enclosures. The relay can be run off a 12V power supply.

 

What does single pole double throw (SPDT) mean?

A single pole double throw relay is used to alternate which circuit a signal or voltage is sent to. It has one terminal on one side of the switch, known as the common, and two on the other side called normally open (NO) and normally closed (NC). When the relay’s coil is not powered, the common connector will be linked to the NC connection. When the relay is powered, the common connector will be linked to the NO connection.

 

Why would I use a relay?

There are several advantages to using a relay. You may want to switch a high current to a lower current, for example controlling a mains operated device using a lower powered switch.

You can use a SPDT relay to connect a circuit in one way when there is no power and another when the relay is active - for example switching from a red light to a green light when the relay is activated.

[Donw]

There are a lot of permutations to relays. I had to adjust relay contacts as a telephone engineer. Not my favourite job.

Don

[Simond]

The old GPO open frame relays were a boon to modelmakers - they provided all the point motors and signal motors for Diggle & Halebarns. I understand they were cheap, but I were nowt but a learner in those days!

 

Best

Simon

[chaz]

The old GPO open frame relays were a boon to modelmakers - they provided all the point motors and signal motors for Diggle & Halebarns. I understand they were cheap, but I were nowt but a learner in those days!

 

Best

Simon

 

They were also a very good way of seeing just what a relay is and how it works. At one time they were easy to acquire but I suspect they may be likes hen's teeth now.