- Contactless Position Sensor for Variable Speed Trigger Switch w/<65μA Ref Design (Rev. B)
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12 May 2016 1,039 views
The TI Design TIDA-00475 demonstrates contactless, robust, cost effective, position sensing for variable speed trigger switches common in power and garden tools.
The MSP430G2x53 microcontroller determines accurately the trigger position and generates the PWM signal to control motor speed and torque. This capacitive potentiometer enables by design high reliability, long life time, and robust operation in harsh environments. The contactless sensing is inherently neither effected by wear down nor moisture or dirt. Therefore it is an ideal replacement for sensitive resistive potentiometers in cost sensitive applications and resolves their reliability issues in harsh environments. The very low power standby operation of the system avoids discharge and damage to the battery pack in case of long term storage.
- Cost-efficient accurate position sensing
- Robust operation in harsh environment in presence of temperature, humidity, supply voltages variations and electromagnetic disturbances
- Step-less high resolution speed command
- Long lifetime of the trigger switch
- Low operation and standby current