Automate those nasty reverse loops, back-n-forth's, and much more with the TRAK-DTRL. This is useful with all types of track power. Use the TRAK-DTRL to automate the reverse polarity function required to operate an automatic back-n-forth. You can also use the TRAK-DTRL to automate the control of polarity reverse type switch machines. You might also want to sequence operations in a certain manner. Whatever you want to operate with a settable and resettable occurrence, the TRAK-DTRL will do it for you!

The TRAK-DTRL is a variation of current detection (TRAK-DT) that includes a latching circuit to hold the relay position. The TRAK-DTRL is unique in that it has memory to its operation. Not only will it remember its last state during a session, it will also remember it between power cycles as well. The TRAK-DTRL varies from the standard TRAK-DT and
other members of it's family in that it has two sense coils. One of these coils operates the relay to its "SET" position, the other input coil operates the relay to its "RESET" position. It does not matter how many times current flows in its "SET" or "RESET" sense coil. It will not change state until a different sense coil is activated. Each sense coil activation is also shown via a RED LED. In the case that both sense coils are triggered at the same time, the "RESET" input coil will take precedence over the "SET" coil's action. Also, if one of the inputs is active, the other input coil is deactivated. This prevents rapid reversal of the relay's position and yields a positive outcome.

Since the relay has double pole double throw (DPDT) contacts, it can be wired as a polarity reversing switch. This allows the TRAK-DTRL to be used with signal's as well as automated reversing loops, various train automation, or polarity reversing switch machine (dc type) control to operate switch machines as well as various other items.

The TRAK-DTRL can also be used to set up sequential functions by having the relay enable other devices when activated and disable these devices when relaxed. A typical way of forcing block or timed stops is to merely turn on a ballast lamp while passing the lamp power through the other detectors sense coils. All kinds of automation and wiring can be done with the TRAK-DT family with simple wiring of the logic you want your trains to do! The RED LED provides for an easy visual indication for which activation has been sensed. They are only illuminated during the sense period and do not indicate the status of the relay's contacts.

It is also necessary to provide power for the electronics. In order for the electronics to function properly it is essential that a "regulated" power supply of 12 VDC be employed. This 12 VDC power is only for the electronics and has absolutely nothing to do with track power. Failure to use a "regulated" 12 VDC can cause erratic functioning or actual destruction of the TRAK-DT which is not covered under warranty. The 12VPS (item 369, pg 37) is ideal for this function.

Below is a basic wiring diagram showing how to splice the Trak-DTRL into a piece of track. Although this scenario might not be of much utility, it can surely be used. When traveling from left to right, the SET would first be triggered followed by the RESET. The distance between the two can be as long as desired. Each input, SET or RESET, can be triggered by any track anywhere. It does not have to be from the same track. That makes many types of operational scenarios for the Trak DTRL.

The green wire connection makes the existing track power connect to each section of track that was made "dead" from the "GAP". The change in color, when routing through the SET and RESET coils, are only for clarification. They all contain the
top rail's track power. The relay contacts would be connected to whatever you wanted to operate.

Powering Switches with TRAK-DTRL (PDF, 105K)