Single Input - Alternating Output

Stall-Motor Switch Machine Drivers

556 Timer

  This circuit is designed to drive Tortoise™ and Cobalt™ slow motion type switch machines. Other makes of stall motor switch machine should also work with this type of circuit. The circuit can also control signal LEDs and low power relays.

  The circuits on this page are Switch Machine drivers that can be used to operate slow motion Stall-Motor type switch machine motors. The circuits use LM556 dual timer chips to provide a PUSH-PULL type output to reverse the polarity of the voltage to the switch machine motors. The output of the drivers is equivalent to a DPDT toggle switch.

  The 556 timers also provide a logic function equivalent to a D type Flip-Flop. This gives the circuit a memory function that allows the turnout to remain in its last position when the control switch is open.

A printed circuit board and parts are available for this circuit.

email

  If you are interested in printed circuit boards please send an email to the following address: rpaisley4@cogeco.ca Subject: Alternating Output 556 Tortoise Driver


Basic Switch Machine Driver Circuit

  The first schematic is for the basic, Alternating Output Stall-Motor Switch Machine driver circuit. There are three complete Switch Machine drivers on each circuit board. No external parts are required.

  NOTE: - If the polarity of the power supply to the switch machine drivers is reversed or the circuit is connected to an AC or DCC source this circuit could be damaged. The maximum supply voltage for this circuit is 15 Volts.


Typical Switch Machine Driver Circuit

  The following schematic is for a typical Stall-Motor switch machine driver circuit controlled by one normally open, push button switches.

Rules For The Circuit Above

  The direction of the motor and the operation of the indicator LEDs depends on the direction of current flow through the output circuits. This can be changed to suit the particular situation by reversing the motor and LED wiring as needed.


Full PCB Circuit Schematic

  The next diagram shows the full circuit of the PCB, including a 100uF supply capacitor that is common to all of the drivers.


Alternating Output Driver Circuit Block Diagram

  The next diagram shows the PCB circuit in block form. This diagram could be used as connection diagram to aid in wiring the drivers.


Alternating Output Driver Circuit Reset Inputs

  The next diagram shows the optional use of the RESET terminals.

  The RESET terminals of the drivers do not have terminal block positions but have solder pads for external connections.



556 Switch Machine Driver Notes


PCB Parts List

QTY DESCRIPTION DigiKey Part #
3 556 IC TIMER DUAL 14-DIP LM556CNFS-ND
6 10K OHM 1/4W Resistor 10KQBK-ND
12 100K OHM 1/4W Resistor 100KQBK-ND
6 1.0uF 50V Biolar Miniature Aluminum Electrolytic UPV1H010MDD-ND
1 100uF 35V Miniature Aluminum Electrolytic P5165-ND
4 2 Position Terminal Block - 5mm ED1601-ND
1 3 Position Terminal Block - 5mm ED1602-ND

  T42-1 Push-In Terminals Push-In Terminals can be substituted for the terminal blocks to reduce costs if desired.



556 Stall-Motor Driver Printed circuit boards

  A printed circuit board and parts ar available for this circuit. There are 3 identical 556 drivers on each board.

  The following is an image of the circuit board which is 3 inches square and is drilled to fit terminal blocks with a 5mm pin spacing.

  The INPUTs are on the left and the OUTPUTs on the right side of the photo.

  The board has been commercially made and is tinned.

556 Alternating Input Stall-Motor Driver PCB - Assembled Example


Option 1 - Circuit Boards Only

  Stall Motor Driver Circuit Boards Only:

  11.00 dollars US each.

  Plus postage.

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Option 2 - Unassembled Kits

  Stall Motor Driver circuit board with all parts:

  18.00 dollars US each.

  Plus postage.

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Option 3 - Unassembled Kits

  Stall Motor Driver circuit boards with all parts except the terminal blocks:

  14.50 dollars US each.

  Plus postage.

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email

  If you are interested in printed circuit boards please send an email to the following address: rpaisley4@cogeco.ca Subject: Alternating Output 556 Tortoise Driver

  Your message will be answered as soon as possible.


Alternating Output Driver Circuit Board Parts Placement Diagram


Additional Circuits


Phototsensor Controlled Alternating Turnout


Tortoise™ Switch Machine Terminal Connections



Circuit Board Assembly

  When installing the components on the circuit board start with parts with the lowest height and work up to the tallest parts. For example starting with the diodes then resistors, IC's, transistors, capacitors and terminal blocks.


Recommended Tools

Soldering



Other Circuits

Light Controlled - Alternating Output



High Current Switch Machines

  The 556 Timer Stall-Motor Switch Machine Driver circuit can drive switch machines that use high current motors such as the Fulgurex type machines, however, these motors operate near the current capacity of the 556 IC's.

  If Stall-Motor Switch Machine Driver is used to drive this type motor then sockets should be used for the IC's to allow easy change out of the 556 timers ICs if needed.

High Current Switch Machine Motor Driver Circuit (Fulgurex)


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Please Read Before Using These Circuit Ideas

  The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.

  If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.

  Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.

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email

  If you are interested in printed circuit boards please send an email to the following address: rpaisley4@cogeco.ca Subject: Alternating Output 556 Tortoise Driver

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06 March, 2017