Switch Machines
The purpose of a switch
(turnout) machine is to move the switch (points) to a
different position so that a train's route is changed.
There are several types of machines. Below are pictures
of some common switch (turnout) machines. A switch
(turnout) machine is an electromechanical device that
moves a lever or arm when a voltage is applied. Each type
has advantages which includes size, ease of installation,
type of control and cost.
Solenoid or twin coil - A momentary voltage causes a
lever to moves to 1 of 2 positions.
Stall motor - A constant voltage causes a lever to moves
to 1 of 2 positions*
Servo - A stream of voltage pulses causes a lever to
moves to many different positions.
* With some additional electronics a Tortoise™ can
be moved to three positions for semaphores.
To remotely control a switch machine in a DCC system an
electronic device called an accessory decoder is
required. Accessory decoders receive commands
(instructions) via DCC commands that are present on the
track just like a loco decoder. Wherever the throttle is
located, accessory control is available. Some throttles
and DCC systems do not provide for turnout control.
Some accessory decodes
provide for controlling switch machines via push buttons
or electrical switches. These are typically used for
local (close or near) control of a turnout or perhaps
from a panel. Team Digital has a number of accessory
decoders to choose from. See products for a comparison.
