Specifications

Detection Equipment, current sense
TRAK-DT Family of detectors.
Overview
This family of detectors has a long history of operation. They were originally produced in 1984 and have been working
flawlessly ever since. While the circuitry has evolved as components have changed and more types have been added to
the line, the basic detection concept remains the same. These are the most reliable detection circuits in the model railroad
industry with the longest service history. There are actually thousands of these in use both commercially and by the home
model railroader. Not only do they detect DC track power but also work with all types of track power. This includes AC,
DCC, and all other types of command control equipment. For the DC operator that wants complete detection, add the
Keep-A-Live and detection continues even when there is no DC track power present! For the true outdoor railroad that
requires low voltage, low current and isolated detection, this is the equipment to use. Contact us for details involved for
this type of operation. It will certainly meet all of the requirements of a safe detection system for all kinds of weather. This
is especially of concern for the 1" and larger outdoor railroads.
The TRAK-DT family of devices provide detection by sensing the flow of electrical current in a wire that is passed through
a hole in the detection coil of the device. These devices are electrically isolated, but function as if they are in series with
the current flow. When current is sensed, a double pole, double throw (DPDT) relay is activated. By connecting the relay
to lights, accessories, other electronic devices, signals or even track power, all forms of automation and / or indications
become possible. A two pin connector is placed on the board so that an additional relay (Item 555) can be added when
extra contact sets are required. While some signals do not require the current capacity of the relay, our customers find it
quite nice to have the added current capacity and to be able to hear the relay engage. This really helps trouble shooting
an installation.
TRAK-DT (TRAcK DeTector) (Item 365, page 37) The basic TRAK-DT activates its relay when current flow is sensed
and the relay is relaxed when current ceases to flow. To detect a train on track it is necessary to isolate a
section of rail defining the block length and to pass the wire feed for this rail section through the detection
coil of the TRAK-DT.
TRAK-DTT (TRAck DeTector Timer) (Item 565, page 38) The TRAK-DTT is a variation of current detection that
provides for event timing. The TRAK-DTT has two modes of operation. One mode provides a timed output
regardless of extended current sense, the other requires current sense to cease and then times out.
TRAK-DTT2 (TRAck DeTector Timer2) (Item 368, page 40) The TRAK-DTT2 is a variation of the TRAK-DTT and
TRAK-DT current detection that provides for event timing. The TRAK-DTT2 has three modes of operation.
The first is trigger of the timer function is preceeded by a latch function. This is activated by the flow of
current. The one mode allows for the timer to time out regardless if the latch input was cleared or not. The
other two modes require the latch input to be cleared. This happens by having current flow ceasing and
then reflowing again and ceasing. The time function will then time out and clear the output. This unit has
some very interesting applications. The easiest is a time stop function.
TRAK-DTRL (TRAcK DeTector R esettable Latch) (Item 566, page 42) The TRAK-DTRL is a variation of current
detection that includes a latching relay that retains it's position, even during power on/off cycles! This
latching circuit is also triggered differently than that of the TRAK-DTL since it consists of two input coils, one
for setting the relay, the other for resetting. Since two input sensors exist, it is possible to constantly
retrigger a setting as many excessive times as needed without changing the state of the relay. This is
extremely handy when doing certain types of automation.
TRAK-DTL (TRAcK DeTector Latch) (Item 366, page 41) The TRAK-DTL is a variation of current detection that
includes a latching circuit to hold the relay position. As a result of this latching circuit, each time current flow
is sensed by the detection coil, the TRAK-DTL changes the state of its relay.
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 or the power of the devices
connected to the relay contacts. Failure to use a "regulated" 12 VDC can cause erratic functioning and/or actual
destruction of these devices. For proper power supply refer to the 12VPS (Item 369, page 35).
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