Point solenoid activation - alternative(s) to switches?

[Junctionmad]

3 hours ago, spikey said:

Gosh, this is all good stuff

 

Ref that points controller circuit, thank you but as I understand it I'd need one per switch, which with 27 switches is hardly feasible.

 

ETA - It's just occurred to me that some of my solenoids are connected to Gaugemaster GM500 relays for frog switching and signal activation.  These are fitted adjacent to the solenoid rather than the switch.  Could this have any bearing on switch failure?

No you just need the transistor circuit, per point , the capacitors can drive as many points as you need , the leds can be removed if not required 

 

hence you have a few jelly bean components per point 

 

to derive the advantage of low currents through the switches you do need a 2x transistor for each point 

Edited October 2, 2020 by Junctionmad

[tomparryharry]

I also have 'push to make' buttons, 2 per point.  Or, for a slip-type point, 4 buttons. On a crossover, you can revert to 2 buttons, as both points work in harmony. 

 

The buttons can or might fail over time. However, the ability to repair without faff makes the experience so much  easier. Designing for this eventuality is the way to go.  I have a control board that I made a few years ago. Although it works, and it looks ok, the wiring behind is bloody awful. I intend to address the lack of get-ability when possible.

 

Cheers,

Ian.

[kevinlms]

3 hours ago, spikey said:

 

My experience of push to make switches is also a good one, provided that they're of decent quality such as from Farnell or RS.  But as I said in my OP, most of the switches on my panels are SPDT momentary.  It's those that are the issue.

 

 

But that wasn't the question.  As I said in my OP, my concern is to arrange things so that after I'm dead, my wife can continue to play trains with the minimum risk of point failure.   Given her aptitude with things mechanical, point failure is about the only issue which would be a major problem for her. 

I don't think you can make it totally foolproof. Even using quality switches, you will get the odd failure - usually caused by releasing the switch too early.

Introduce your wife to someone that would be able to assist, on the odd occasion. Perhaps joining a club would be a possible solution?

[Butler Henderson]

Alternative is stud and probe with nothing to wear out 

[spikey]

5 hours ago, Butler Henderson said:

Alternative is stud and probe with nothing to wear out 

 

Indeed it is.  But my problem there is I've never seen a picture of a stud-and-probe board that looks anything like what I'd call businesslike.  Those that I have seen pictures of all looked like lashups involving a sheet of ply, some round-head screws and a converted Biro.  Not saying that a kosher stud-and-probe board can't be done - just that I've never seen one!

[Butler Henderson]

51 minutes ago, spikey said:

 

Indeed it is.  But my problem there is I've never seen a picture of a stud-and-probe board that looks anything like what I'd call businesslike.  Those that I have seen pictures of all looked like lashups involving a sheet of ply, some round-head screws and a converted Biro.  Not saying that a kosher stud-and-probe board can't be done - just that I've never seen one!

Probably screws because people bulk at paying Pecos price for a small pack of studs and tag washers. When I've used stud and probe I've used flat head nails as being neater in appearance together with a multimeter probe 

[spikey]

15 minutes ago, Butler Henderson said:

... together with a multimeter probe 

 

Oh nice one!  I'd never have thought of that

 

BTW your namesake locomotive was a regular around the Grimsby area back in the late 50s.  I once got a ride in the cab "all" the way from Cleethorpes to Grimsby Docks station.   Unfortunately, pretty much all I remember of the trip was that the fireman was so Scottish I couldn't understand a word he said ...

[cravensdmufan]

8 hours ago, tomparryharry said:

I also have 'push to make' buttons, 2 per point.  Or, for a slip-type point, 4 buttons. On a crossover, you can revert to 2 buttons, as both points work in harmony. 

 

The buttons can or might fail over time. However, the ability to repair without faff makes the experience so much  easier. Designing for this eventuality is the way to go.  I have a control board that I made a few years ago. Although it works, and it looks ok, the wiring behind is bloody awful. I intend to address the lack of get-ability when possible.

 

Cheers,

Ian.

I have exactly the same set up Ian.

 

A nice looking panel diagram with push switches but a massive jumbly nest of wires behind it!  What the eye doesn't see..... 

 

Never had any push button switch or solenoid failures in the last 9 years yet....but now that I've gone and said that.....! 

[kevinlms]

9 hours ago, spikey said:

 

Indeed it is.  But my problem there is I've never seen a picture of a stud-and-probe board that looks anything like what I'd call businesslike.  Those that I have seen pictures of all looked like lashups involving a sheet of ply, some round-head screws and a converted Biro.  Not saying that a kosher stud-and-probe board can't be done - just that I've never seen one!

Some don't even use a converted biro. At my club, we had a multimeter cord fail, just after the start of an exhibition.

The temporary fix, was a length of flexible wire with the end stripped and soldered. The fix lasted years and just got resoldered every now and again!