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Current Limiting board

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					                 DC Motors
                                                Units: mm           to motor      from PSU

                                                                           37.5
                                                                                                                             Miniature Motors,Transmission and Control
                                                                                                                        20                                3x M2.5 fixing holes
                                                                           25.7

                                                                                                                                                   25.7                                   20




                                                                                                                                                               27.3
                                                 4x M2.5 fixing




                                                                                             54.6
                                                 holes



                 Current Limiting PCB                                                                                                +V from PSU
                                                                                                                                                                                5   1.6

                                                                                                                                                           +V to motor
                                                                                                                                      0V from PSU
                                                                                                                                                         0V to motor
                                                                                                              5   1.6                  4 lead wire length 200mm
                                                                    from PSU     to motor
                 Issue 03                                        4 lead wire length 200mm
                                                                                       Bi-Directional Unit                                                 Uni-Directional Unit


  Use of the Current Limiting PCB allows the maximum current available to a DC motor to be fixed. This
  allows normal operation of the motor up until the set limit, beyond which the motor will quickly stall. This
  is particularly useful to protect gearboxes where an unlimited motor could apply a torque great enough to
  cause damage to either the application or gearbox.
  Whilst the unit can provide 2000mA at voltages below 12V, the unit is limited to a maximum current of
  800mA at 24V. Contact Rotalink for advice on current ratings at other voltages.
  The current is fixed at the factory by Rotalink in line with customer requirements.

  The current limit pcb is designed to limit the motor current for only short periods of time. If the current
  required by the motor is above this limit for long, the output current of the unit will reduce. The graphs
  below indicate this current reduction over time. Care must be taken to ensure that the current does not
  drop below the minimum required to start the motor.

  Characteristics - Current Drop with unit at current limit
  (24V, 22°C)                                                                                                                  General Specification
                                                                                                                               Current limit               100mA to 2000mA
                 0.9
                                                                                                                               Rotation                    Uni or bi-directional
                                                                                              Current (0.8)   R82
                 0.8
                                                                                              Current (0.7)   R82
                                                                                                                               Supply voltage                        to 30V DC
                 0.7                                                                          Current (0.6)   4R7              Voltage drop                                1.4V
                 0.6                                                                          Current (0.5)   4R7              Uni-directional Wiring
Current (Amps)




                 0.5                                                                                                           Positive voltage from PSU                             Red
                                                                                                                               Ground (0V)                                          Black
                 0.4
                                                                                                                               Positive voltage to motor                             Red
                 0.3
                                                                                                                               Bi-directional Wiring
                 0.2
                                                                                                                               Connections to PSU                        Violet+White
                 0.1                                                                                                           Connections to motor                       Red+Black
                  0
                       0    20   40   60   80         100           120              140            160           180
                                           Time (seconds)


  Characteristics - Current Drop with unit at current limit
                                                                                                                               Contact:
  (12V, 22°C)
                 2.5
                                                                                                                               www.rotalink.com
                                                                                              Current (2.0)   R39              info@rotalink.com
                                                                                              Current (1.5)   R39              T: +44 (0)1460 72000
                  2
                                                                                              Current (1.3)   R82              F: +44 (0)1460 74278
                                                                                              Current (0.8)   R82
Current (Amps)




                 1.5                                                                                                           Rotalink Limited
                                                                                                                               Cropmead, Crewkerne
                  1                                                                                                            Somerset TA18 7HQ, UK

                 0.5



                                                                                                                               www.rotalink.com
                  0
                       0    20   40   60   80         100           120              140            160           180
                                           Time (seconds)

				
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posted:3/10/2010
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Description: Current Limiting board