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US 2006/0187567 A1Published application
Motor driver and magnetic disc apparatus
OwnerMitsuaki Daioinventor
Life of this patent
Estimating the term…
Abstract
When the drive current fed to a VCM 3 is large, a driver D2 is turned on, and a driver D3 is turned off so that the current detected by a current detection amplifier A1 is fed back based on the voltage across a detection resistor RS1. When the drive current fed to the VCM 3 is small, the driver D2 is turned off, and the driver D3 is turned on so that the current detected by a current detection amplifier A2 is fed back based on the voltage across a detection resistor RS2.
Claims13
A motor driver including:
- a current output driver that outputs a drive current fed to a direct-current motor;
- and
- a gain switch circuit that switches a current/voltage gain for a value of the drive current with respect to an input voltage;
- the motor driver comprising:
- n detection resistors connected in series with a coil of the direct-current motor;
- n switches provided one for each of the n detection resistors, each switch having one end thereof connected to an end of the corresponding detection resistor farther from the coil, and having a predetermined direct-current voltage applied to another end thereof, and
- n current detection amplifiers provided one for each of the n detection resistors, each current detection amplifier detecting a voltage across the corresponding detection resistor and feeding the detected voltage back to the gain switch circuit;
- wherein turning on and off of the switches is controlled according to the current/voltage gain switched by the gain switch circuit.
5 more elements
A motor driver including:
- a current output driver that outputs a drive current fed to a direct-current motor;
- and
- a gain switch circuit that switches a current/voltage gain for a value of the drive current with respect to an input voltage;
- the motor driver comprising:
- a first detection resistor having one end thereof connected to a coil constituting the direct-current motor;
- a second detection resistor having one end thereof connected to another end of the first detection resistor so as to be connected in series with the first detection resistor, the second detection resistor having a different resistance from the first detection resistor;
- a first switch having one end thereof connected to a node between the other end of the first detection resistor and the one end of the second detection resistor, the first switch having a predetermined direct-current voltage applied to another end thereof;
- a second switch having one end thereof connected to another end of the second detection resistor, the second switch having a predetermined voltage applied to another end thereof;
- a first current detection amplifier that detects a voltage across the first detection resistor and feeds the detected voltage back to the gain switch circuit;
- and
- a second current detection amplifier that detects a voltage across the second detection resistor and feeds the detected voltage back to the gain switch circuit;
- wherein turning on and off of the first and second switches is controlled according to the current/voltage gain switched by the gain switch circuit.
9 more elements
Dependencies are inferred from the claim text.