Linear Motor Control MUSCLE PHYSIOLOGY The SI-H Linear Motor Controller is designed for use with the SI-H line of muscle physiology research platforms. For systems that require a linear motor, this unit provides the precision control of the motor. A linear motor is required for measuring mechanical muscle properties such as slack-test, isotonic release, constant velocity release, stretch release, vibration studies, after-loaded contractions and eccentric contractions (intact muscle). The position of the linear motor is determined by a combination of the data from the controller indicating the current position and the DC value applied to the front panel at the Position In port. The applied Position In signal can be provided by a data acquisition system (Lab-Trax 8/16). The data acquisition analog output signal is set to define the waveform and timing pattern of force to be applied to the sample. The Linear Motor Controller has been designed with an automatic shutoff feature. That means that the voltage driving the motor automatically shuts off if the motor draws too much current. After less than a second, the motor cycles back on again. If the setup still draws too much current, it repeats the power down cycle. This could happen if too much force is being applied to the sample. The system continues to cycle the motor off and on until the force on the motor is reduced. If this happens, the motor hums as if it is trying to work, but the motor produces no force output. If an auto-shutdown occurs, adjust the experiment and force tension on the motor. The motor is setup and calibrated to the Linear Motor Controller that is shipped with it. The motor and controller have a maximum range of motion of ±3.5mm from the center of travel. The Position In BNC interface provides for an external position command input. The input range is ±10VDC. The signal presented at the input will affect the length of motor travel. The motor/controller combination are calibrated for travel of 1.0mm/2.0VDC. For example, +7VDC translates to +3.5mm of travel from the center, and –7VDC equals –3.5mm of travel from the center. This input could come from the Lab-Trax-8/16 Data Acquisition system or an SI-COLUB Constant Load Module. NOTE: Use of a linear motor with a muscle testing platform creates vibration which excites the sensor’s resonant frequency and requires an Programmable Filter module (SI-PF100) for best results. ●● Powers the motor and provides an output indicating the actual motor position ●● Connects to Analog to Digital Converter output of the computer or data acquisition system (like Lab-Trax-8/16) to allow the programming to control the waveform and timing of the motor control ●● Input range of ±10VDC ●● Over current protection that automatically shuts down when the supply voltage dips below the reference value ●● Linear motor position is determined by a DC value applied from the Position In port SI-MOT-MT SI-MOT-MKB SI-MOTDB Linear Motor for SI-HTBM system Linear Motor for SI-MKB Linear Motor Controller SI-MOTDB SPECIFICATIONS POWER REQUIREMENTS 12V DC provided by the chassis ±10V DC 1 mm/2 VDC current 7 mm ( ±3.5 mm from center of travel) INPUT TRAVEL MAXIMUM TRAVEL The SI-MOT motor can be used with any SI-HTB Horizontal Tissue Bath or SI-MKB Muscle Research System. 12 UK: Tel: +44 (0)1462 424700 • wpiuk@wpi-europe.com World Precision Instruments www.wpiinc.com Germany: Tel: +49 (0)30-6188845 • wpide@wpi-europe.com US: Tel: 941-371-1003 • sales@wpiinc.com