VCM Driving Circuit with Adjustable Reference Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voice coil motor (VCM) driving circuits face challenges in setting the optimal current range due to differences between VCM manufacturers and models, leading to inefficiencies in power consumption and flexibility.
Innovation Solution
A bi-directional driving circuit with a current detection circuit, error amplifier, and drivers that allow for external setting of the reference voltage, enabling flexible adjustment of the driving current range by using a current detection circuit and error amplifier to generate an error voltage for switching the driving current between source and sink states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional bi-directional driving circuit with fixed symmetric current range is used, then the circuit structure is simple, but the adaptability to different VCM models and manufacturers is poor
Solution Approach 1:
The patent implements dynamic adjustability of the driving current range by allowing external setting of reference voltages VREF1 and VREF2. This enables the circuit to adapt to different VCM models and manufacturers by dynamically changing the current range parameters, transforming a static symmetric circuit into a dynamic configurable one.
Solution Approach 2:
The patent changes the electrical parameters (reference voltages VREF1 and VREF2) of the driving circuit to achieve different driving current ranges. By externally setting these reference voltages, the circuit can accommodate various VCM specifications without hardware modification, resolving the contradiction between simplicity and adaptability.
2Use of energy by moving object
If the driving current range is fixed at zero center, then the circuit design is straightforward, but the ability to optimize power consumption for different reference positions is limited
Solution Approach 1:
The patent enables flexible setting of reference positions by allowing external adjustment of reference voltages VREF1 and VREF2. This parameter change capability allows the system to optimize power consumption by setting the reference position at non-zero current levels, accommodating different application requirements.
Solution Approach 2:
The circuit transitions from a fixed zero-center current range to a dynamically adjustable current range that can be shifted to optimize power consumption. The ability to externally set reference voltages provides operational flexibility for different reference position requirements.
3Reliability
If separate driving circuits are designed for different VCM specifications, then each circuit is optimized for its specific VCM, but the overall device complexity and design workload increase
Solution Approach 1:
The patent creates a universal driving circuit that can accommodate multiple VCM specifications through external setting of reference voltages. This single circuit design replaces multiple specialized circuits, reducing design workload while maintaining optimization for different VCM models through configurable parameters.
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 configuration allows for precise control of the driving current range, optimizing power consumption and flexibility in driving various VCMs, enabling the circuit to function with both bi-directional and spring return methods, and reducing design complexity.
Implementation Method 1
a current detection circuit that generates a detection voltage VS=VREF+k×IDRV, with the driving current as IDRV
Implementation Method 2
an error amplifier that amplifies a difference between the detection voltage VS and a control voltage that indicates a position of the voice coil motor so as to generate an error voltage
Implementation Method 3
a voice coil motor that includes a coil and a moving element, and that drives the moving element in a first direction or a second direction according to a direction in which a current flows through the coil
Data Source
AI summary
With a driving current as IDRV, with a reference voltage as VREF, and with a gain as k, a current detection circuit generates a detection voltage VS represented by VS=VREF+k×IDRV. An error amplifier amplifies a difference between the detection voltage VS and a control voltage that indicates a position of the VCM so as to generate an error voltage VERR. A first driver switches the driving current IDRV between a source current and a sink current with respect to one end of the coil according to the error voltage VERR. A second driver switches the driving current IDRV between a sink current and a source current with respect to the other end of the coil according to the error voltage VERR. The driving circuit allows an external circuit to set the level of the reference voltage VREF.