Wiring two signals together

[AndyID]

It should be possible to do it with simple change-over switch with a center-off position but it's actually quite tricky 😀

 

The problem is it needs an inversion, that is a NOT something. e.g. the ENTER state and its opposite NOT ENTER state. (EXIT is not the opposite of ENTER.)

 

That can be done several ways. A relay, a very basic diode/transistor circuit or some CMOS logic gates in a chip.

[melmerby]

How about abandoning the slide switch and having a 3 position rotary wafer switch?

That way you can get rid of all the diodes and just switch on the signals you want at each position

 

https://www.ebay.co.uk/itm/362597550559?hash=item546c7f89df:g:-8AAAOSwBP1iRzO6&amdata=enc%3AAQAHAAAA8Jx59a%2BvgfdaJmy3GwV%2B38dGwbX9NPNQ31UdF%2FxzmZ8ioBV1nKZlYvsruu6E3yqMQnoxNCV2Yh84ko7uG%2FFX0zq4iVMyMLbaccnc78F5ye%2Brx2eOODp7Pit9hF5Qb6GUB7j9Jh3E%2FFt1WGo%2B4cIeIrlUXgm9aMuEOsXg5i5vaSk5pHB97RqaP5PCJEp65iUU1NJuDp2NpefhzrTH5qCXSp7cxxcZXw54nF1TIQPwt%2F8B1ux%2By4XwmYerx%2BFzctq7ER5RRoK%2BtdqHrGGXwd%2B6xizHSkGK4MTPscQ4qV4vXZL3JWv5kzoI5t6qji%2BOHVTWnA%3D%3D|tkp%3ABFBMvr2gxKpg

 

Or possibly use a slide switch with more contacts:

https://www.ebay.co.uk/itm/254222022352?hash=item3b30d036d0:g:3wEAAOSwfHBa3FRp

[AndyID]

5 minutes ago, melmerby said:

How about abandoning the slide switch and having a 3 position rotary wafer switch?

That way you can get rid of all the diodes and just switch on the signals you want at each position

 

https://www.ebay.co.uk/itm/362597550559?hash=item546c7f89df:g:-8AAAOSwBP1iRzO6&amdata=enc%3AAQAHAAAA8Jx59a%2BvgfdaJmy3GwV%2B38dGwbX9NPNQ31UdF%2FxzmZ8ioBV1nKZlYvsruu6E3yqMQnoxNCV2Yh84ko7uG%2FFX0zq4iVMyMLbaccnc78F5ye%2Brx2eOODp7Pit9hF5Qb6GUB7j9Jh3E%2FFt1WGo%2B4cIeIrlUXgm9aMuEOsXg5i5vaSk5pHB97RqaP5PCJEp65iUU1NJuDp2NpefhzrTH5qCXSp7cxxcZXw54nF1TIQPwt%2F8B1ux%2By4XwmYerx%2BFzctq7ER5RRoK%2BtdqHrGGXwd%2B6xizHSkGK4MTPscQ4qV4vXZL3JWv5kzoI5t6qji%2BOHVTWnA%3D%3D|tkp%3ABFBMvr2gxKpg

 

Or possibly use a slide switch with more contacts:

https://www.ebay.co.uk/itm/254222022352?hash=item3b30d036d0:g:3wEAAOSwfHBa3FRp

 

The simplest way to do it would be with two switches, but what would be the fun in that 😀

 

They could even be mechanically linked so that only one can be ON at a time but they can both be OFF.

[meil]

On 10/06/2022 at 11:57, Heinz57 said:

Thanks chaps,

 

I have found these on RS, would they do the job?

 

https://uk.rs-online.com/web/p/toggle-switches/7347053

 

https://uk.rs-online.com/web/p/toggle-switches/7347012

 

Wiring in diodes isn't a problem, but what size do I need and where would I need to wire them?

 

Cheers,

 

Matt

Yes they look the job. Diodes - the 1N400X series will do the job.

[wagonbasher]

Hi

 

i always find these things fascinating.

 

if the flashing beacon flashes because something is moving, do things only move when they ‘enter and exit’?  Is there no scenario where things move that are not ‘entering or exiting’?  
 

Any idea how the prototype would have worked, would the flashing light have come on at the same time as the lights changed from ‘enter to exit’, who is pulling that lever, flicking on the hazard light.

 

if the flashing light is an independent switch then the game is over.

 

sorry to question the brief.

 

Andy

[Heinz57]

My question about the compatibility with the Absolute Aspect signals could be struck. I've been having a little think and I'm looking at making my own signals, it will cut down cost and will gurantee its compatibility with the circuit diagrams kindly provided for me.

 

3 hours ago, wagonbasher said:

Hi

 

i always find these things fascinating.

 

if the flashing beacon flashes because something is moving, do things only move when they ‘enter and exit’?  Is there no scenario where things move that are not ‘entering or exiting’?  
 

Any idea how the prototype would have worked, would the flashing light have come on at the same time as the lights changed from ‘enter to exit’, who is pulling that lever, flicking on the hazard light.

 

if the flashing light is an independent switch then the game is over.

 

sorry to question the brief.

 

Andy

 

I'm not 100% sure. As far as I know they are their to warn of anything moving. In reality I don't think they are connected to any signals, I remember seeing them flashing away at the Etches Park open day a few years ago even though no stock was moving. I want to wire them to the signals on my layout just to simplify the operation.

[AndyID]

Crikey! I just looked at what they cost. You could buy a lot of LEDs for the price of one signal.

 

I think it might have been better if they had used common positive rather than negative. That would make it simpler to drive them with some basic electronics. For example the electronics could be powered from five volts and it would only have to ground the signal's input to turn on the led. 

[Heinz57]

Yeah at £30 a go they aren't cheap! They look absolutley fantastic and work reliably well. But when I need sixteen of them it'll cost far too much.

[AndyID]

17 minutes ago, Heinz57 said:

Yeah at £30 a go they aren't cheap! They look absolutley fantastic and work reliably well. But when I need sixteen of them it'll cost far too much.

 

If you do make your own I'd suggest you just use regular LEDs with resistors and run them from a 5 volt wall-wart rather than 12 volts.

 

I'd probably do it like this.

 

Each signal has the circuit with the transistor (the "repeat" box is the same circuit for the other signal). The transistor acts as an inverter meaning that if the green LED is on the transistor turns off the red LED. When the green led is off the inverter turns on the red LED. The beacon is powered when either of the green LEDs are on. When the switch is in the center OFF position the beacon is off and both signals are red.

 

The circuit could be put on a very small piece of Veroboard. If you like this method I can come up with a component list. It will be very inexpensive 😀

[Heinz57]

Thanks Andy.

 

I've examined the diagram and it looks a little complicated. I might have to use the one John posted the other day, it looks a little more straight forward. But thanks all the same, I appreciate the time you took to design it.

 

I have a bit of vero board knocking around somewhere from my uni days... I think

[AndyID]

17 minutes ago, Heinz57 said:

Thanks Andy.

 

I've examined the diagram and it looks a little complicated. I might have to use the one John posted the other day, it looks a little more straight forward. But thanks all the same, I appreciate the time you took to design it.

 

I have a bit of vero board knocking around somewhere from my uni days... I think

 

No problem. That's the one Dave John posted? Yes, I believe that will work too. The difference is it requires a three position switch. I was trying to do it with a center off switch.

 

Cheers,

Andy