diode matrix and stall point motors

[gwrman]

Hi, I want to operate a three way point with Cobalt point motors but I normally operate one with solenoid point motors with a matrix, my question is can the Cobalts be worked with a matrix and is their any different wiring.

 

Nigel

[gordon s]

Hi, I want to operate a three way point with Cobalt point motors but I normally operate one with solenoid point motors with a matrix, my question is can the Cobalts be worked with a matrix and is their any different wiring.

 

Nigel

 

This may help, but I did get into a long discussion with the author regarding manual switching. (I'm assuming Cobalt wiring is the same as that for a Tortoise).

 

http://www.awrr.com/matrix.html

 

Here lies the problem. The diode matrix is for setting specific routes, but you may need to use one of the turnouts to access a shed or a siding for which a diode matrix would be an overkill, so you would have a manual switch on your control panel to do this. With solenoid motors this is not an issue as you are simply providing power to one side or the other. If the turnout is set correctly, the diode matrix will simply ignore it. If set incorrectly, it will recognise this and change it to suit the route.

 

The problem with stall motors is that you are reversing the polarity to operate the stall motor in each direction. The use of a manual switch in a similar application to that above will really confuse the polarity switching. I'll try and dig out the mail I had from the circuit designer...

[gordon s]

Found it....

 

 

Gordon,

I think there are several ways to do this: 1. Each turnout would have a 3-position rotary switch for its control; the positions would be (a) route [the diode matrix], ( closed, or © thrown.

 

If the switch is in the "route" position, then it would respond to the route selection from the matrix; if turned to the "closed" or "thrown" position, that setting would override the route setting and cause the turnout to assume the selectedosition.

 

OR 2. Each turnout would have two toggle switches for its control; switch #1 would be route/manual, and switch #2 would be closed/thrown (active only in the "manual" position of switch #1. If switch #1 is set to "route," then its turnout would respond to the route selection from the matrix; if set to "manual," then the closed/thrown control takes precedence and cause the turnout to assume the selected position.

 

OR 3. Similar to (2) above, but with a toggle switch and a relay vs. two toggles; the toggle would have a center-off position, which would allow the diode matrix to control the turnout; the same toggle could be pushed up or down corresponding to a closed/thrown manual override.

 

I can also envision an all-logic solution, but that really starts getting a bit involved. I hope the above descriptions are clear enough to get you thinking about which way you might find most appealing. Let me know your thoughts and/or questions.

I can do a drawing to help clarify the wiring of whichever solution we choose.

 

Regards,Fred

 

Sue and Fred HorneSanta Fe NM USA

www.awrr.com

 

 

On Dec 6, 2009, at 8:53 AM, Gordon S wrote:

Hi Fred

Thanks for getting back to me. Just some background. I have a large terminus with six platform roads and a diesel and steam loco servicing area plus a goods yard. There is an up and down line plus a goods line coming in/out of the terminus.

The route setting comes into its own when I can easily select say platform 1 for an incoming train and several turnouts can be set. However, once the train has arrived and the coaches removed, there will be a loco which will need to go under local control away to the service shed. This will mean the loco going back across several routes, hence the need for local switching to set the turnouts.

With solenoid motors this is very easy as local switching will overide the diode matrix or vice versa.

I'm not sure this can be achieved with stall motors as you are switching polarity via on/on switches. The need would be just the same with either the switch or the route taking precedence depending on which one was selected. Even if you overcome it electrically, the mechanical/visual position of the switch will not change, so I don't think it can be achieved, but thought I would ask the question anyway.

I'd still be interested to hear your views, but don't spend too much time on it...:-)

Regards

 

Gordon S

Sent:

Sunday, December 06, 2009 3:07 PM

Subject:

Re: Route selection using Tortoise motors

 

 

Gordon,

 

Hmmm...I think this is the first time I've had this question. Before I say something dumb, let me be sure I understand what you're wanting to do: 1. You want to have BOTH a route selection rotary switch AND individual turnout control toggles for each Tortoise -- is this correct? 2. Which would take precedence? ie, if the route selector says that motor "N" is to be closed, but the turnout control toggle says it should be thrown, who wins? I think it can be done, but it may get a bit complicated. How much complexity (beyond the rotary selector and the toggle) are you willing to endure?

 

Let me know, and I'll see what I can do.

 

Regards,Fred

Sue and Fred HorneSanta Fe NM USA

www.awrr.com

 

 

Hi, I've seen your circuit on the web and it's just what I require, but I do have a question for you.

I have built a diode matrix for solenoid motors before and that worked well. The switches used were momentary/centre off, so power was not supplied until the switch or route selection switch was operated. One would overide the other depending what was used.

When using Tortoise motors the current is permanently on and the switch is a single pole on/on switch. At present I can't see how you can use individual turnout switches as well as the route selection switch. Is this possible?

I'm not an electronics engineer, but believe that once the route selection had taken place, the toggle switch on the turnout would be incorrect to the way the turnout was set to accomplish the route setting.

I wonder if you would be so kind to confirm that it is or is not possible to have individual turnout switches as well as route selection with Tortoise motors. If it can be done, do you have a circuit diagram?

 

Many thanks

 

Gordon S