Route setting with servo controller

[ikcdab]

My new layout is preogressing. DC control, but i am using servos for point motors worked by a megapoints controller.

There are 10 turnouts. I would like to have push button route setting, and there would be 8 different routes. 

In the past, with solenoid control, i would have built a diode matrix and linked it to a CDU.

Now i see that the servo controller requires a continuous power feed for a servo to "lie" one way and the absence of any power to lie the other way. They suggest simple toggle switches.

I can see how i might modify a diode matrix, but then i get stuck. If i power up one route (by toggling its switch on), i would need to untoggle it before i set another route, which sounds awkward. 

I could use an 8-way rotary switch, but i would prefer an electronic solution. The megapoints controller has a memory function which does what I want, but only has 3 routes.

how do i go about this?

If it helps, the track diagram showing the different power supply sections is attached.

Thanks

 

[RobjUK]

One way, not necessarily the cheapest but functionally the simplest, is to use a double coil bistable (aka latching) relay for each point.

 

Connect the relay contacts with power to common and no/nc to the two feeds to the point. They will stay in whichever state they are set until you apply power to the opposite coil.

 

Then use your diode matrix to feed power to the appropriate relay coils for each route combination.

 

This type of thing:

 

Examples, functionally similar but different makers use different pinouts:

https://uk.rs-online.com/web/p/latching-relays/7181838/

 

https://www.ebay.co.uk/itm/12V-Coil-Bistable-Latching-Relay-DPDT-2A-30VDC-High-Quality-Free-Postage/123813253177?hash=item1cd3d85039:m:msOr1KIVL5yp2RLccgiVqBg

 

 

If the points need a higher current pulse to move and lower holding current, connect an appropriate capacitor and resistor in parallel and add that combination in series between each relay contact and the point solenoid. The capacitor will provide an initial current pulse, then the resistor defines the holding current.

 

 

Edited August 14, 2019 by RobjUK

[Tricky Dicky]

Having only watched the video and not read the manual for the megapoints controller it would appear that  each channel is activated by taking the input pin to 0V that would lend itself to be being controlled by a PIC microcontroller such as PICAXE or Arduino. It should be a fairly simple process to produce a program so a single switch can be used to produce a sequence of outputs to set a route.

 

Richard

[Junctionmad]

The easiest way is to wire logic set reset latch’s to the input lines of the mega points controller , this then lets you use a push button for each direction , ie one button press for normal and the other button press for reverse ( and hence use diode routing as required ) 

 

A CMOS 4043 for example 

 

Edited August 16, 2019 by Junctionmad

[ikcdab]

Thank you for all your replies. Very helpful.