Timepiece Motor Control for High-Load Rotation
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Solution Overview
Problem
Electronic timepieces with stepping motors experience increased power consumption due to high rotational loads, particularly when the rotor is in positions requiring first and second auxiliary drive pulses, leading to inefficient energy use.
Innovation Solution
A timepiece motor control method that adjusts the energy of drive signals based on detected rotational loads, using main, auxiliary, and sub-drive signals to minimize power consumption by outputting the appropriate signal for the current rotational load, and stopping unnecessary chopper signals at high-load positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If first and second auxiliary drive pulses are output when rotational load is high, then the rotor can rotate, but power consumption increases
Solution Approach 1:
The system performs preliminary detection of the induced signal before outputting drive pulses. By detecting the induced signal in advance and comparing it with a reference threshold, the system determines whether high rotational load exists beforehand, allowing selective output of auxiliary drive pulses only when necessary, thus avoiding unnecessary power consumption while ensuring reliable rotor rotation when needed
Solution Approach 2:
The system uses feedback from the induced signal detection to control the output of drive pulses. The rotation detection circuit continuously monitors the induced signal and feeds this information back to the control unit, which adjusts the drive pulse output accordingly - outputting normal drive pulses when rotational load is normal and auxiliary drive pulses only when high rotational load is detected, thereby optimizing power consumption while maintaining rotation reliability
2Measurement precision
If chopper signals are continuously output for rotation detection, then rotation state can be monitored, but power consumption increases
Solution Approach 1:
Instead of continuously outputting chopper signals, the system uses periodic action by only outputting chopper signals when necessary - specifically when the rotor rotation state needs to be detected after drive pulses are output. The chopper signal output is synchronized with the drive pulse timing, creating a periodic detection pattern that maintains rotation state monitoring capability while significantly reducing power consumption compared to continuous monitoring
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces power consumption by preventing the output of drive signals with excessive energy and stopping unnecessary chopper signals, thereby optimizing energy use during normal and high-load rotations.
Implementation Method 1
A main drive signal for rotating the rotor 202 by 180 degrees in the forward-rotation direction, a sub-drive signal for rotating the rotor 202 by 180 degrees in the forward-rotation direction when a high-load rotation position is detected, and an auxiliary drive signal for rotating the rotor 202 by 180 degrees in the forward-rotation direction are respectively applied to a coil 209
Implementation Method 2
a rotation detection process for detecting the rotation state of the rotor 202 based on an induced voltage output to the coil 209
Data Source
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AI summary
There is provided a timepiece including a high-load rotation position detection unit that detects a high-load rotation position that is a rotation position of a wheel when a rotational load of a rotor that transmits rotor's rotation to the wheel and rotates a pointer clockwise is greater than that during normal hand movement and a drive signal output unit that outputs a sub-drive signal having energy greater than that of a main drive signal that is output during the normal hand movement and less than that of an auxiliary drive signal that is output when the rotor does not rotate by the main drive signal in a case where the rotation position of the wheel is the high-load rotation position.