If you mean the black panel-face-mount controller with the blue slider, that's a Single-Pole, Double-Throw, Momentary contact unit.
I've found these Atlas things to have a poor reliability record. The worst case scenario, which happens all too frequently, is that the switch sticks in the ON position and fries your switch machine. Atlas will be happy to sell you another one, though. So, I heartily approve of your decision to use something else.
Yes, you need center-off. You'll see these in catalogs as either SPDT(Mom) or maybe (ON)-OFF-(ON), where the parentheses around "ON" indicate momentary contact.
It takes an iron man to play with a toy iron horse.
I don't use momentary toggle switches. Instead, I put a pushbutton in the "common" line from the switch (turnout) machine. So, I throw the double throw toggle to connect the "normal" or "reverse" coil of the switch machine and then press the pushbutton to provide a short zap of power.
I find these advantages to this system:
It is very simple, reliable, and cheap. Almost any pushbutton you buy will almost never stick in the closed position. No more fried switch machines. No complicated and expensive capacitor discharge parts.
The position of the toggle indicates what direction the turnout is in.
If you use double-pole, triple-pole, or even quadruple-pole toggles, you can run panel indicator lights, turnout indicator lights, and provide power to powered frogs, all without a switch machine relay.
Disadvantages:
You have to make two motions, throw the toggle and press the button, to operate the turnout.
You have to "initialize" your turnouts by operating them first one way and then the other when you fire up your layout to make sure the turnouts are in the position that the toggles say they are to guard against manual operation of the turnouts out of sync with the toggles.
If you make a manual operation, which is quite easy with Atlas turnouts, you have to remember to go back and throw the toggle.
If you have separately powered frogs, a manual operation will leave the frog with the wrong connection and cause a short.
I use the system because I find the advantages outweigh the disadvantages.
cordon wrote: I don't use momentary toggle switches. Instead, I put a pushbutton in the "common" line from the switch (turnout) machine. So, I throw the double throw toggle to connect the "normal" or "reverse" coil of the switch machine and then press the pushbutton to provide a short zap of power.I find these advantages to this system: It is very simple, reliable, and cheap. Almost any pushbutton you buy will almost never stick in the closed position. No more fried switch machines. No complicated and expensive capacitor discharge parts. The position of the toggle indicates what direction the turnout is in. If you use double-pole, triple-pole, or even quadruple-pole toggles, you can run panel indicator lights, turnout indicator lights, and provide power to powered frogs, all without a switch machine relay.Disadvantages: You have to make two motions, throw the toggle and press the button, to operate the turnout. You have to "initialize" your turnouts by operating them first one way and then the other when you fire up your layout to make sure the turnouts are in the position that the toggles say they are to guard against manual operation of the turnouts out of sync with the toggles. If you make a manual operation, which is quite easy with Atlas turnouts, you have to remember to go back and throw the toggle. If you have separately powered frogs, a manual operation will leave the frog with the wrong connection and cause a short.I use the system because I find the advantages outweigh the disadvantages.
I like it!
Actually, I get the same result from a shorting rotary switch, so there's no separate pushbutton. With MZL control, my electrically powered switches can be thrown from the CTC panel (M,) the zone control panel (Z) or from some point close to the turnout when in walkaround mode (L.) The CTC panel uses 4p3t rotaries, the zone panel uses 3p4t rotaries and the local control is a pair of pushbuttons. Manual throw (fingers in the machinery) of electrical machines is not an option, since the throwbars are connected to under-subgrade machines by Anderson links.
Rail power (to frog, and to MZL propulsion circuitry) is handled by contacts on the switch machine (I do not use contact-free Atlas machines.) The extra contacts on the rotaries are used for inter-panel signaling and to transfer control from Z to either M or L.
Chuck (modeling Central Japan in September, 1964)
The type of switch used for controling turnouts and snap relays is a Momentary Contact Single Pole Double Throw (SPDT), which means that there is only one set of contacts and two sets of positions. The way a switch controler works is that you have your 3 contacts, usually wired with Red, Yellow, and Green wires, with Yellow in the center. Now, AC power is used coming into the controler, and is routed with one side of the AC being constant in the center position, going out to the Yellow wire, and the other side of the AC going out to the Red and Green wires by selecting the side that it is on and activating the momentary contact switch.
If you don't want to use the controller that Atlas uses, one way to wire your switch machines is to send one side of your AC current directly to the center of the switch machine, and split the other side of the AC current and use push buttons to activate the switch machine. Here is a simple diagram of what I mean. I hope this helps.
--- is Red/Green Wire== is Yellow WireO is Push Buttono is Switch Machine Terminal/AC Power pack Terminal
/-----------O-----------------o Left From AC on Power Pack: o---------< (wires split at this point) \-----------O----------------o Right o==================o Center Contact
I hope this isn't too confusing and answers your question.
Ya know, I've used the Atlas switch controls for a long time, the same ones, and I have not had one stick or burn out a switch machine (knock on wood). So besides the looks, (I always thought the push buttons looked better) they seem to do the job.
Tilden
First of all, Cordon, that is a REALLY cool idea. I just finished building my control panel with sets of two push-buttons.... but you've got me thinking I want to rip it out and do the whole thing over. GOOD IDEA!
Also to Teamanglerx (the original poster).... before you invest a lot of money in Atlas table top switch machines, consider under table Tortoises. They do cost more, but are totally reliable, never meltdown, you can easily add signal lighting with no additional electronics except the LEDS, no ugly switch machine to hide on tabletop, wonderful slow motion movement, and simple wiring. Well worth the investment. No I don't work for them, just love the product. Yes, I've got loads of tabletop machines that I'm slowly replacing -- generally as they melt.