Suzie

If you can get an original battery go for it - it is quite hard to get hold of original batteries for a lot of stuff now. There is no way to guarantee an aftermarket battery will be any good, but I have found that Duracell ones tend to be OK from the Duracell outlet.

B40FS appears to be available from eBay:-

https://www.ebay.ie/itm/B40FS-DIO-Bridge-rectifier-80V-1A-SMD-slim-Features-fast-B40FS-x6-pieces-/172936885684

I am sure that Farnell will have something - I will have a look later.

If the signal was weak a bigger aerial would have been purchased - unlike today the aerial was a lot cheaper than the television set then!

That said it was normal to mount the aerial at a height to have good line of sight to the transmitter. A bit of 2" pole was not a big cost in the scheme of things.

On the 'H' aerial the element nearest the transmitter is slightly shorter. 

Unlike nowadays when the aerials are made from pure aluminium and remain relatively shiny until they fall apart, in those days a stronger alloy called Duralamin was used which weathers to a darker grey. Smoke would often make them completely black.

The 'H' or 'X' aerials are for BBC only, you still need the ITV one as well for the period you are modelling.

Yes, ITV aerials would be vertically polarised yagis on channel 10, and BBC aerials would typically be Antex 'X' type or yagi 'H' type on channel 2 pointing roughly towards Huddersfield for the Emley Moor (ITV) and Holme Moss (BBC) transmitters.

These aerials are quite typical of what you might see in Yorkshire. The small aerial is a later UHF type that would have been added after the introduction of BBC2 in 1966.

What date is your building? Pre-decimalisation implies that not everywhere would have UHF for TV so the small aerials we have today might not be present.

Where is your building? Different areas had different transmission arrangements in VHF days with separate aerials being required for BBC (often a H or X type) and ITV (smaller multi element Yagi). Some areas used horizontal aerials while others used vertical. Often BBC and ITV aerials would point in different directions because transmitter sites were not shared.

Date and place is key. A TV shop would of course be fitted with the latest type of aerial - and might be the only place with a BBC2 UHF aerial for those giant 26" dual standard TV sets!

Lenz need to have the BEMF tuned to the motor - you will have trouble doing that with capacitors in. I suspect they come with very conservative settings as default which may be why you have little problem - the BEMF is probably nearly switched off as supplied.

On 05/04/2019 at 20:23, Art Dent said:

Additionally ....

 

You may find that a small stay alive/anti-flicker circuit is helpful.  The following pictures show the small curcuit that I use in OO-gauge stock (you haven't said as far as I know which gauge you are working in)

 

 

Circuit Diagram

 

 

Components

 

 

Finished unit (approx 25mm long and 13mm in diameter)  Red & Black leads are the 12V DC feed to the lighting strip, the two yellow leads are the DCC feed to the bridge rectifier.

 

 

Showing the unit being tested on a 3-LED strip.

 

Hope this helps,

 

Art

The DI202 rectifier is not suitable for DCC, it is a DC only device in this context. A faster bridge is required for DCC.

You will need to experiment. I suggested the Zimo decoder in that £20 per rake is probably not too big a price to pay to just have a single decoder in the rake.

Memory usage might be more important.

If you are running your LEDs from track voltage you can put a few in series, and if using white LEDs you will not have to run them at full power.

I suspect the 0.5A you can get out of a Zimo decoder should be enough to light a whole rake.

You might like to think about getting a roll of 12V LED light strip...

Try Rapid for example:-

https://www.rapidonline.com/tt-electronics-t6370st-24vdc-1a-24w-uk-plugtop-smpsu-2-1-c-ve-85-3746

Other mail order suppliers are available.

Solenoids typically work best at 24V DC from a CDU - Since the PSU you have looks to be an old transformer based one you will probably get around 16V DC out of your CDU when used on the 12V setting which will give around 2/3 power which may be enough if the motors are well fitted and lubricated.

If it does not work just get hold of a modern 1A 24VDC regulated PSU instead and you should be fine.

The simpler the decoder the less it will be affected by suppression capacitors - they mainly affect the motor feedback that keeps the train running at constant speed with varying load.

If you have a good decoder and want it to behave like a cheap decoder switch off the feedback, or alternatively snip out the capacitors and reap the benefits.

There are not enough poles on a DPDT switch to do this so what you are asking for is impossible. It gets extremely complicated when you get to a junction and you have to light the feather as well.

To do this on plain track with just switches you would need to use 4PDT switches.

In practice it will probably be easier to use 4-pole relays and have some form of occupancy detection rather than using switches.

The lower switch can work in conjunction with a point, but the top one can't unless a second DPDT switch is interspersed to reverse the feed connected to the other crossover so that if both points are normal there is no reversal, and if either is reversed the feed will be reversed (ignore the scenario when both crossovers are set!) Probably not too hard to gang an extra DPDT switch to give four poles on one of the crossings - it certainly simplifies the wiring at the cost of an extra pole.

I just don't count flangeways as isolating breaks - they have to be there!

On 10/03/2019 at 12:22, Suzie said:

There are three states in practice which makes the wiring a bit more intuitive:-

 

• All straight
• Crossing bottom left to top right
• Crossing top left to bottom right

I am assuming that you will feed both routes from one end and not require power routing and that you can operate the two points of each crossover with a single switch. DCC would have made this a lot easier, but you should be OK.

 

Note that the frogs of points 1 and 3 are connected together as are the frogs of points 2 and 4 to make life easier.

 

I could not do it all with DPDT switches, so you might have to add a microswitch to point 1 to get the extra pole.

 

If you need power routing you will need extra poles for that too. Wiring is common return with the black feed being the common.

 

 

15 minutes ago, Grovenor said:

There should be 16 isolating breaks, not including seperation of DC track sections (which Clive included). Of course using Peco turnouts and not isolating the frog from the switch blades does reduce it by 8, but I would not expect to do that on hand built track.

OK, Ian, assuming this is one slide switch per point, then you will have to manage manually the operation of one crossover at a time to avoid shorts on the diamond. The wiring can be biased to allow use of one crossover but not the other if both are reversed.

Can you confirm that it can all be in one power supply section as it is in the yard?

In this case one slide switch per point will do.

 

So far as isolating gaps go there should be 16! Not 4 or 12.

Each turnout needs 2 gaps to isolate the frogs from the switches, that is 8.

Each of the 4 rails across the diamond needs a gap to prevent a dead short, another 4.

And the two common crossings in the diamond need to be isolated from the adjacent stock rails, another 4.

Regards

 

Keith

You might like to count the isolating breaks on my diagram above from halfway down page 1. It does show five breaks but that was before I found out that only a single track feed was required eliminating one of them (blue, green, red and orange feeds are all the same). The only isolating breaks required apart from the obvious are on the two diamond frogs. 

Only one slide switch per crossover is required (both points of each crossover operated from one switch) but one does need to be a three pole one for this scheme.

I will leave it to the OP to decide which scheme to use - simple track configuration with minimal rail cuts (my method) versus simple wiring using two DPDT switches (AndyID/Clive method).

5 hours ago, Izzy said:

The requirement for the OP, is for DC ( it is in the DC section), just using the DPDT slide switches that work the individual point tie-bars via tube/wire if possible, which it is, to keep it simple and easily produced. 

 

Izzy

 

added - actually this general question has been asked here before, in 2015, and clearly and simply answered by Clive Mortimore. The details are here: 

https://www.rmweb.co.uk/community/index.php?/topic/86612-home-made-scissor-crossing-and-control/

 

read his post, about halfway down the first page. Pretty much what I will be posting with specific details about the Templot configuration Ian will be building.

 

 

Clive ignored the OP's requirement to keep the frog triangles intact (only four isolating breaks in the whole scissors) and provided the same solution that AndyID has already proposed above (which has twelve isolating breaks).

1 hour ago, Pete the Elaner said:

3 states?

All points set to straight. The crossing can be dead for this. As long as it is isolated, does it matter which way it is powered?

All points set to crossing. Top rail needs to be the same polarity as top rail & bottom needs to be same polarity as bottom rail.

1 crossover straight & the other to crossing. Why bother? Every usable scenario has just been covered.

The problem with your scenario is the crossing frogs - the polarity reverses between crossing one way and crossing the other way. There is no way round it other than switching in conjunction with crossing one way or the other - or separately switching those frogs.

1 minute ago, Pete the Elaner said:

I fully agree that only 2 states need to be considered: All straight & all crossed. Any others involve running in to a point not set.

With all points set to straight, the crossing needs no power at all, so I would isolate all rails. YOu only then have to consider how the crossing needs to be wired when the points are set to use it.

You do not need to take power from any switched frogs. If you only consider the crossing with the points thrown, you can take the feed directly from one of the main line feeds. If you have cab control, you could choose which circuit to include the crossing in.

So I would ignore the feeds from the frogs to the crossing, which are wrong anyway.

The polarity of the crossing frogs has to be changed depending on which crossover is being used. It is not possible to set 'all crossing' when using a live frog diamond in the middle. There are three states!

The feeds from the point frogs to the crossing frogs are quite correct when using Andy's scheme which requires twelve isolating breaks on the six frogs.

2-pole switches will require breaks around the four point frogs (eight of them) so that you can just link the crossing frogs to the point frogs and have one pole per point frog.

I tried very hard to rework it but DPDT + TPDT is the best I could get either way while maintaining the structural integrity as far as possible with breaks just on the crossing frogs.

1 hour ago, AndyID said:

 

And you are absolutely correct!

 

You might getaway with two states for the points but the diamond's frogs must be set according to the route.

Your diagram will work, it just needs a few more insulated gaps than my method. The discipline of only setting one crossover at a time still applies.

1 hour ago, AndyID said:

 

If Ian promises to never foul the points he can make it even simpler and go with a two-state (all straight/all crossing) version in which case he won't need any additional switches

The issue for this method is that the diamond frogs will need to be set depending on which way you are going through the crossover - that is why there are three states and not two.

1 hour ago, AndyID said:

Ian's scissor crossing is in a goods yard. I'm not sure he's going to need that much complexity

If it is 'one engine in steam' then all four feeds will be the same and that will simplify things a lot. Context is all!