turnout toggle controls

S:

I could see at least one occurring. The story would involve a brass locomotive, a stub-end siding, a weak bumper, and a table edge...of course I don't own any brass locos, so I can't verify by experiment.

Honestly, my remote switches have tended to be either bone-stock Atlas-type with their own controllers, or Rube Goldberg manual remotes with fishing line and popsicle sticks. I like the SPDT toggle with momentary button plan - you'd get panel indication of position with the toggle, and simple momentary control. One could, however, insure against pushbutton failures by using a set of auxiliary contacts to cut power the the machine after the switch was thrown.

You could just switch to Tortoise switch machines and avoid the cutout problem altogether. I may end up doing that with my current layout, where I'm going to have to include some electric remotes (crossing section borders of a knockdown portable layout is a little too Goldbergian even for me). I think this is the best course to follow, if you don't have a pile of Atlas machines already.

Cordially yours: Gerard P. President, a box of track and a gappy table.

Hi Tex,

it's a case of "do as I say, not as I do". ;-) Did I mention flux?

Greg.P.

tex shalter wrote:

I've settled on Peco turnouts and Peco motors and auxiliary switches, as the price/quality/supply/functionality is adequate. Their standard auxiliary switch isn't up to end-off switching. One thing I like about the Peco setup is that the turnout can be remotely or direct manually operated. In that situation electrical feedback is vital to _my_ control systems. Atlas is ok, in fact I've used those for my major staging yard, but there's no reasonable way to add auxiliary switching.

By the time Tortoises reach me in New Zealand the price is prohibitive. :-(

GP1:

Isn't it always?

Cordially yours: Gerard P. President, a box of track and a gappy table

I could claim perfection, but ...

Greg.P.

Greg Procter wrote in news: snipped-for-privacy@ihug.co.nz:

Sounds pretty cool. I tend to keep things very simple wiring wise for people who may not be in to the electronics part of it. Most people can wire a switch, stringing together components and making spaghetti isn't thier idea of fun. :-)

It's really nice when throwing one switch realigns all the turnouts in the crossover.

Puckdropper

tex shalter wrote:

Ah yes, the great turnout control issue. Firstly there are two types of switch machine out there. The twin coil machine (e.g. Atlas Snap Switch) and the stall motor type (e.g. Tortoise). The twin coil machines draw a lot of juice (amps) and are designed for intermittant power. They want a short pulse of juice. If they get constant juice they overheat and bad things happen within a matter of minutes. You want pushbuttons or momentary contact toggle switches, ones that are spring loaded to the OFF position and only make while your finger is pressing them. For a twin coil machine, a Single Pole Double Throw (SPDT) momentary contact is sufficient. You can use Double Pole Double Throw (DPDT) switches if you have them, but the double poles are not necessary. Twin coil switch machines are hard on switches. The coils are inductive (natch) and the inductor causes heavy arcing when the switch opens. You want a heavy duty switch. The lighter weight Radio Shack switches will fail more often than you like. Buy the biggest ones they have. If you are buying a batch, buy some spares and plan on changing them as they die. Few toggle switches are momentary contact, most of them are lock in place, keep the power on types, which will pop a twin coil machine in short order. With Atlas snapswitch machines there is no good way of indicating the turnout position, short of looking at the rails themselves. Fancier twin coil machines have auxilary contacts that can drive panel indicator lights. The stall motor switch machines have a number of advantages. They move the points slowly and realistically rather than banging them back and forth the way the twin coil machines do. You don't need the hard to find momentary contact toggle switches, the ordinary lock in place type work just fine. You can wire LED's in series with the switch motor to indicate switch position, saving the extra runs of wire back from the distant switch machine to the control panel of fascia. The stall motor machines cost more than the simplier twin coil jobs.

David Starr

Nothing wrong with Atlas Snap Switch machines. They are rugged, cheap and dependable. You just don't get the luxury of indicator lights, at least not without buying "Snap Relays" which cost about as much as the switch machines themselves, which seems like a little bit much to my ears. If you are into that sort of thing you can build a capacitor discharge power supply from not much at all. The idea is the supply has a big capacitor charged up to 30-40 volts. When the switch connects the charged capacitor to the coils of the twin coil machine, all the juice in the capacitor runs thru the coil and then the capacitor is discharged. Should one of your working switches stick ON (the arc welds the contacts shut) no harm is done, the capacitor is out of juice and so the the coils don't over heat. A CD supply is just a big capacitor with a small charging circuit. You need 10000 microfarads at least and 47000 is better. Surplus caps are findable. Be sure to get the polarity right, they go bang if hooked up backwards. Make sure the cap is rated for 35 volts. The charge circuit is just a 24 volt furnace thermostat transformer and a Radio Shack full wave bridge rectifier. The whole thing will fit inside an old PC power supply case.

David Starr

Also, if you're using twin-coil style switch machines, use a capacitance discharge unit to power the machine instead of simply hooking up a power supply. That way, if one of your toggles gets stuck, you won't melt the switch machine (this happens very quickly!).

There's a lot of ways to do that, here's just a few:

- Have a "snap relay" (essentially a twin-coil machine without a switch) hooked up in parallel to the actual switch. Both flip, and the contacts on the snap relay handle your lights. Pro: Easy. Con: ridiculously old fashioned.

- Use a twin-coil machine with extra contacts for signals. Peco machines have a little snap-on widget for this, or with a little fooling around you might be able to make the turnout itself do the work. Pro: More accurate. Con: Can be complex to wire up a switch for this, solutions may end up costing more than snap relays. Or the turnout.

- Use a tortoise machine, which is made for this sort of thing. Pro: Easy, and requires no CD circuit. Con: Some don't like the slow switching. Machines must always get some power to keep the turnout in place.

- Go DCC and use signaling controllers (I swear by the team digital SIC24). Pro: Incredibly flexible - you can do prototypical signaling without lots of handwiring. Con: DCC only. Takes a while to get comfortable with. Not a good fit if you like to hand-toggle switches (unless you like lots of extra wiring for switch feedback). Needs a computer to set up efficiently. Must use turnout decoders (the SMD8, or digitrax's equivalent, for example).

Personally, I like the DCC solution because of the cool things you can do with it. But for a small layout with just a few switches it can be a bit of overkill. One thing about doing it the old fashioned way, you will learn a lot about good wiring in the process. You'll also learn how to manage wires under the layout, because there will be a LOT of them. *