Wiring a CTC Panel

OK. Now, how can I connect multiple cab controls to the track and still use the direction toggle switches?
Thats still just as easy. All you need is a rotary switch. For X number of cab controls, you will need a 2 pole - X+1 position rotary switch. For my 5 cab controls, I have 2 pole - 6 position rotary switches. Your switch can have more than X+1 positions but not less than X+1. The extra position is used as the OFF position when NO cab has control of the circuit.

If you want more than two cabs, you will need ROTARY switches for this. Even if you only want two cabs now, plan for expansion and use rotary switches. You could use DPDT switches for a two cab system but I will not cover that as I think it would be a big mistake to even consider ending up limited to two cabs maximum.

The confusing part here may be all the types of rotary switches available and understanding the connections on them. Without trying to cover ALL the variations in rotary switches, I'll explain the two basic types. The most common have multiple wafers. That's like stacking pancakes. Each wafer works like a single roatary switch and the wafers are stacked (this is called ganged) to give multiple poles (circuits). A three pole rotary switch would have 3 wafers and three circuits thereby acting like 3 rotary switches working together.

Rotary Switch Basics

The rotary switch gets its name from how it operates - it rotates (or turns). Each pole is a flat wafer. Part of the flat surface is covered with a conductive metal and some is not. In diagram 9, the grey areas represent the metal surface area. By changing the pattern of the metal-covered surface, the operation of the switch varies. This metal pattern is called the foil pattern (foil meaning metal). Metal contacts ride (slide) over the surface as it turns closing (as it touches the foil) and openning connections. A contact is shown below the wafer.

Diagram 9

Diagram 10

See diagram 10. The common contact 'C' will touch the inner ring of the foil as the wafer rotates all the way around. Contacts 1, 2, & 3 will touch the foil leg from the inner circle one at a time as the wafer turns. As shown, contact 3 is connected to the common contact. A wafer switch can easily have a dozen, or more, contacts and is limited only by size.

A rotary switch can also have unlimited wafers, or poles. The wafers are simple 'stacked' and turn together. The rotary switch shown in diagram 11 is a three wafer, four-position switch (OFF -1-2-3) or a three pole, four-position switch. It switches three circuits simultaneously. Each wafer (pole) has a common contact and 3 switched contacts. The three wafers are referred to as A, B & C.

Diagram 11

By changing the foil pattern, a single wafer can control several poles (circuits). However, the wafer can NOT turn all the way around when used this way. Notice how the inner ring has been 'cut' on the wafer shown in diagram 12. The leg pointing up connects to the right side of the ring and the leg pointing down connects to the left side.

Diagram 12

Diagram 13

The example in diagram 13 is a TWO pole THREE position single wafer rotary switch. It is shown in position 1. The left side is circuit A and the right is B. Terminal 1 on the right side is connected to terminal B here. By turning one position clockwise, terminal 2 on the right side would connect to terminal B. One more turn clockwise and terminal 3 on the right side is connected to terminal B. Likewise for the left side (A). My CTC is constructed with 6 position rotary switches. This means I have a 5 CAB capability (using the first as OFF) but I only have three CABs wired up.