The k83 (6083) accessory digital decoders for momentary power are used for controlling switches, signals, uncouplers, and other accessories that operate off a solenoid. These decoders can be mounted on the top of the layout or underneath and each unit can control 8 solenoids. If signal and switching operations are to be used, it will take two connections at the k83 unit since signals and switches work with two solenoids. The unit is designed primarily to work with switches and solenoids and so the color codes and arrangements of the sockets in the decoders are easy to interpret for the three wires that connect to those accessories.

Each decoder has two power connections on each side of the unit labeled red and brown, and four sets of three wire sockets labeled red, yellow (or neutral), and green. The power connections will connect directly to a track section or to the brown and red connectors at the Central Unit. For ease of connection, it is advised that a feeder track be installed with the brown and red leads connecting to the decoder. In this way the unit receives its power from the track and correct polarity on the hookup wires is assured. Extreme caution should be taken so these leads are never reversed or else the computer circuits will be damaged. The second set of power connections is provided for connecting to another decoder. After the first unit is connected to the track, it is not necessary for other units to have track connections, but can rather connect to the first decoder. This is not mandatory, they can connect to track that may be closer or to the Central Unit.

Each of the four sets of three sockets are assigned the order 1 through 4 beginning at the lower left of the unit and moving in a counter-clockwise order.

On both the k83 and k84 decoders a 8 position dip switch panel is accessible by opening the unit with a screwdriver. These switches are factory set for: Keyboard number 1, buttons number 1 through 4. This would be noted on the top of the decoder; at the upper left of the cover is an identifying code such as "1(1)". The first "1" saying this is connected to Keyboard #1, and the "(1)" noting that this k83 unit controls switches 1-4. If switches 5-8 were connected the code would read "1(2)". These codes and the corresponding switch settings are noted in a listing provided with the accessory decoder. Each Keyboard can control 4 of the k83 units, and a total of 16 Keyboards can connect to the Central Unit. This makes a total of 64 k83 units that can possibly be installed on one layout using one Central Unit.

When connecting to Märklin switches, it is easy to know which wires on the switches will connect to the corresponding color coded sockets on the k83. The switches have three wires, one yellow and two blue. One of the blue leads is shorter than the other, this is usually the lead that connects to the green socket on the k83. This green socket will set the switch straight. If it is a signal that is being connected, the same principle holds true. The shorter lead is the green light wire. The other wire is connected to the red socket and sets the switch to the curve. If this doesn't work, simply reverse the two blue wires. The remote control relay #7245 can be connected in the same manner as the switches. This unit can then be connected to lights or other accessories.

If your connecting Märklin uncoupling tracks, only one of the red/green sockets and the yellow socket are needed. With single solenoid accessories like the uncoupling track, the solenoid will be active for as long as you hold the button down on the Keyboard. When the button is released, the uncoupler will stop operating.

Signals on the digital layout can be used to control blocks of track in the same manner as on conventional layouts. For example, a center rail can be isolated according to directions provided with the switch by means of the isolators available from Märklin, or stiff card stock. The signal is then connected to a power source and the blocked section of track so that when the light is green, power is provided to the isolated section of track. This operation is usually found in connection with sidings and switches so the track that is switched off has no power and the signal is red. When the switch is set to the siding, the signal turns green and power is fed to the track.

Digital layouts and k83 units will support this same operation with one correction. In order for the engine that is on the dead section of track to keep its memory while off, it must receive a constant trickle of power from the Central Unit. This is accomplished by bridging a resistor (1.5 kilo ohm, 1/4 watt) between the two red leads (center rails) on the track. This is shown on the illustration below. Two of these resistors are provided with each k83 unit.

When all the switches and accessories are connected to the k83, do not test them by touching power from connections on the Central Unit or a transformer to the red and green plugs. This will burn out the transistors in the k83 unit.

Unlike the k83 decoder which is designed to operate solenoids, the k84 decoder controls constant power accessories such as lights and motors. These decoders are basically a set of four double throw switches. A motor has both leads connected to different ports on the decoder which allows for the direction of the motor to be reversed by changing the settings on the Keyboard which in turn changes the decoder switches.

If the decoder is intended to control switches or signals that operate on two wire DC power, it is necessary to build a relay circuit that will switch the three wire power coming from the decoder to the two wire needs of the DC solenoid.

Notice for 1 Gauge:

5625 turnout or 5613 signal -----k83 decoder
connection 1 - - - - - - - - - - - -> green socket
connection 2 - - - - - - - - - - - -> red socket
connection L - - - - - - - - - - - -> yellow socket