Three-Rail Innovations' controller products are activated by isolated outside-rail track sections, provide the right features for the accessories being activated, and isolate accessory power from track power.

Click to compare with other activation methods.

Following headings give details on Three-Rail Innovations' controllers' better activation techniques.

Better Than Just An Isolated Outside-Rail

Reliable Activation at Precise Train Positions

Short Track Blocks Can Work

Between Two Short Track Blocks

Combining Multiple Track Blocks

Right Features for Accessories and Train Control

Isolated Accessory/Train Power

Three rail toy train track provides a distinct advantage for the toy train operator wanting to use the position of trains to operate trackside accessories or to control train action: the track itself can be used for a low-cost, practically invisible, mechanism for detecting a train's location.

Accessories can be operated with isolated outside-rails implemented with any three-rail track system. See Track Systems .

Three-Rail Innovations' controller products go the isolated outside-rail technique one better by:

• Compensating for wheel bounce and dirty wheels.
• Separating power used for activating an accessory from that used for powering it.
• Allowing the use of short track blocks and pairs of track blocks to replace long isolated track blocks.
• Allowing one isolated track block to operate more than one accessory and allowing more than one isolated track block to operate the same accessory.

An isolated outside-rail provides precise activation by train position. Three-Rail Innovations' Controllers improve reliability by compensating for wheel-bounce and dirty wheels.

The isolated outside-rail is activated when the leading wheels enter the track block. Activation is "held" so wheel bounce will not cause a false drop-out.

The activation is held while the train proceeds through the block. The train can be of any length, moving at any speed, and even stopped with track power off. Activation is held under any circumstances.

Activation is held until the last wheels leave the track block, even if there is more wheel bounce.

The single, reliable, activation as a train moves through an isolated outside-rail track block provided by Three-Rail Innovations' controllers improves the operation of accessories; no extra light blinks or chattering of solenoids.

Even more, this reliable activation allows isolated outside-rail track blocks to be used to control trains.

Three-Rail Innovations' controllers can provide an extended hold so activation is continuous even if long rolling stock spans a short isolated outside-rail track block.

Sometimes a layout allows only a short track block for accessory activation. Using just a single isolated outside-rail track section can be a convenient tradeoff to modifying the track of an existing layout. Some track systems, like Super-O, provide isolated track sections, but don't encourage modifying track for an isolated outside-rail.

Three-Rail Innovations' controllers can be employed to provide reliable activation of accessories, even if only a short track block is available.

The isolated outside-rail is activated when the leading wheels enter the track block. Activation is "held" so wheel bounce will not cause a false drop-out.

The activation is held while the train proceeds through the block. The train can be of any length. Activation is held even if the trucks of long rolling stock span the short track section. A continuous activation is provided as long as the train is not stopped with trucks spanning the track section.

Activation is held until the train leaves the track block and the extended hold time expires.

Three-Rail Innovations' controllers can be used to activate accessories using only a short isolated outside-rail track section.

Three-Rail Innovations' controllers also allow two short track blocks to substitute for long isolated outside-rail track blocks.

A track block for controlling accessories or trains is constructed with a short isolated outside-rail track section, then any length of track that does not have an isolated outside-rail, then another short section of isolated outside-rail track.

An accessory is activated from the time a train enters a short track block, until is completely leaves the second short track block.

The isolated outside-rail is activated when the leading wheels enter the short track block (A). Activation is "held" so wheel bounce will not cause a false drop-out.

Activation is held as the train moves over the short track section. The train can be of any length. Activation is held even if rolling stock trucks span the short track section or the train is completely within the track length that does not have an isolated outside-rail or if the train stops.

The controlled accessory remains activated as the train enters the second (B) short isolated outside-rail track section.

The controlled accessory is turned off when the train leaves the second (B) short isolated outside-rail track section.

The same action occurs when a train traverses from the (B) to the (A) short track sections. Variations are available to only activate an accessory when a train traverses in one direction, but not in the other direction, across the short track sections.

Three-Rail Innovations' controllers can be used to reliably activate accessories or control trains even when track blocks cannot be fully isolated or contain crossovers, switches, or special track sections that are difficult to isolate.

Three-Rail Innovations' controllers allow extensive use of isolated outside-rail track blocks for operating accessories and controlling trains. They allow an accessory to be activated by more than one isolated outside-rail track block and an isolated outside-rail block to control multiple accessories.

The following simple example demonstrates how Three-Rail Innovations' controllers can be used to take full advantage of isolated outside-rail track blocks for operating accessories. Two adjacent isolated outside-rail track blocks, designated (A) and (B), are shown. They are connected to Three-Rail Innovations' controllers for activating accessories:

• The (A) block operates a block signal.
• The (B) block operates a crossing gate.
• The (A) and (B) blocks operate a flashing crossbuck.

The (A) block activates a block signal and a flashing crossbuck. Block (A) is activated when a train enters it. The block signal changes from "green" to "red" and the crossbuck starts flashing.

The (B) block activates a crossing gate and the flashing crossbuck. Block (B) is activated when a train enters it. The crossing gate starts to lower. The crossbuck, already flashing, continues to flash.

When the train leaves block (A) the block signal changes back to "green." The crossing gate stays down. The crossbuck continues to flash, since it is also operated by block (B).

When the train leaves block (B) the crossing gate starts up and the crossbuck is turned off.

The example can be extended for two or more tracks at the highway crossing, without adding additional controllers.

The techniques presented in this simple example can be extended to any number of isolated outside-rail track blocks, any number of Three-Rail Innovations' controllers, and any number of accessories.

Only with Three-Rail Innovations' controllers can the isolated outside-rail be fully utilized for controlling accessories and trains.

Its the controllers' features that add ACTION to your layout.

Everything from flashing crossbuck lights to allowing two trains to safely negotiate a track crossover. Click to see the features provide by each controller.

• The 2RC, Two-Relay Controller provides twenty features for operating trackside accessories, controlling trains, providing train safety, and operating track switches.
• The Universal Trackside Accessory Controller really is "universal;" it will operate any trackside accessory. UTAC, Universal Trackside Accessory Controller describes available "features" (the eleven ways that the UTAC can operate), and how features control accessories.
• Three-Rail Innovation's 2LR, Two Lighting Relays, Features provide timing and counting for operating lighting accessories and lights in structures on a train layout.

Three-Rail Innovations' controllers isolate accessory power from the track for better and safer operation.

An isolated-rail track block can be used to directly operate an accessory by electrically connecting the accessory to the insulated rail.

However, the requirement for connecting accessory power to track power for both activating an accessory and supplying power to the accessory has some problems:

• Because accessory power common and train power common must be connected together, not all available transformer voltages can be used.
  The KW transformer shown previously illustrates this problem. Since the "U" terminal must be connected to the outside rail for train power, only the "A," B," 6V, or 20V terminals can be used for accessory power. The desirable 14V terminals cannot be used, since neither terminal can be connected to the outside rail.
  Some modern transformers can actually be damaged if posts designed for train power and posts available for accessories are connected together.
• All the power to operate an accessory is being carried by train wheels and axles. Not a problem for low current lights, but some solenoid activated accessories can draw two amperes of electrical current.
• A derailment can put track power through the accessory.
• Activation by train power, operator switches, and other useful techniques are precluded.

Three-Rail Innovations' Controllers utilize isolated outside-rail track blocks, but without any of these problems:

• Each controller relay or electronic switch is isolated from the track. Any transformer power can be connected for operating an accessory. Completely separate transformers, that is, with no common connections, don't need to be phased.
• Power used for activating a controller is very small; all accessory power is through electronic switches or relay contacts. No damaging current is carried through wheels and axles.
• The accessory is completely isolated from the track, so a derailment will not cause damage.
• Controllers can be activated by any combination of train power or an activating transformer. Operator switches and relay contacts can be used for activation, in addition to one or more isolated outside-rail track blocks.

Three-Rail Innovations' Controllers' are superior to any other way of operating trackside accessories or controlling trains.

They are far superior to weight-operated switches, a direct isolated rail, track relays, engine power sensors, or interrupted light beam devices.

• Weight-Controlled Contactor -- Weight-controlled contactors like the Lionel 145C depend upon the weight of a train and track construction for proper operation. They are fussy to adjust right, can't provide precise block transitions, seldom provide a continuous closure, and don't provide capabilities for flashing a light, ringing a bell, or limiting how long an accessory is activated. They are big and ugly and track has to be loose for them to work at all.
  
• Direct Connection to an Isolated Rail -- An isolated rail directly connected to a trackside accessory can only be used to turn something on; alone, the technique can't be used for block signals, prototypic crossbucks, or bells nor can accessory operation be for a limited time. All the power used by an accessory passes through train wheels and axles. Derailments can put track power to the accessory.
  
• Isolated Rail and Power Relay -- A recent product marries a power relay to an isolated-rail track section. While this solves some of the problems of the direct isolated rail connection, it only uses track power for operation, and still doesn't properly operate flashing lights etc.
  
• Engine Power Sensor -- Another recent product senses electrical current through the track center rail and closes a relay. It needs track power for operation, still doesn't properly operate flashing lights etc., and can't detect freight cars that draw no electrical power.

  This technique can't be used for train safety or train control features since there is no way to know when the end of a train has cleared a track switch or crossover. Any operation is dependent upon train length.
  

• Interrupted Light Beam -- Another product provides a relay closure when a train interrupts a light beam positioned on either side of the track. The device is rather large, can be fussy to adjust, and can be false triggered by room lighting. It doesn't properly operate flashing lights etc. and continued activation is based on time, rather than just train motion.

Connections to outside-rail track block can be almost invisible. You don't need fussy, engine weight-controlled, track clips, large (and expensive) track relays, special track sections with large attached growths, and you certainly don't need unreliable light detectors taking up space on both sides of a track.