Thanks inobu...what I’m thinking is that one day I’ll want a junction fitted with a proper interlocking lever frame (such as the one furnished by Modratec of Australia -
www.modratec.com) and set up using Kato switches, however I need some kind of switch which I could tack to the lever rods which would furnish the necessary power “blip” to move the switches.
What you would need to make that work is a switch that momentarily sends current in one direction when set one way, and momentarily sends current in the other direction when moved the other way. That's a problem. Then you'd need to mechanically couple it to the lever frame, so that pulling the lever throws it one way, and pushing the lever throws it the other way. That's not too hard if you're mechanically inclined (levers and springs at worst).
The switch is what would be described as an (on)-(on) DPDT (the parenthesis around "on" indicates it's momentarily connected, not continuously connected). The problem is that, as far as I can tell, they don't make those (other than in the form of Kato's blue switches and similar, which appear to be too large for what you want). One solution is to couple an on-on mini DPDT (always on) switch wired as a reversing switch with a momentary push button, which is how the old Atlas turnout switches worked (slide the switch to reverse current, then push it down briefly to make contact). With that, you could mechanically couple an on-on DPDT wired as a reversing switch to the frame, throw the lever by hand, and then push a button in front of the lever to throw the turnout. Not quite prototype, but only one button and you would need to use the lever frame, so somewhat prototypical.
Alternately, you could make something with brass strips and some copper-coated PCB strips (the kind sometimes used for ties) so that the lever frame moved a contact over two contact points, leaving it on a dead spot at either end. What that would do when you threw the lever is first throw the turnout in the direction its already set (which does no harm), then as you move the lever further throw the turnout in the other direction, before coming to rest in a position with no current flowing. The only hard part might be that there isn't enough travel in the lever frame, and you'd need to use a mechanical lever to increase the throw distance to fit in all the contacts and dead spots needed.
Finally, there are ways to make an on-on switch act like an (on)-(on) switch, but they require more complex circuits. There is a nice set of examples
on this page (I don't understand the first diagram, but the second one with the SPDT looks like it would do what you need). With one of those, you could just couple the on-on switch to the lever frame and throw the lever to throw the turnout. But you'd need to replicate the circuit for each lever.
An on-on mini switch, in either
SPDT or
DPDT forms, is fairly common.
