Abstract: According to one embodiment, a connection tester includes first input terminals connected to first output terminals of a signal supply unit which supplies a signal, second output terminals connected to second input terminals of a device connectable to the first output terminals, a plurality of wiring members connecting the first input terminals and the second output terminals to each other, a plurality of switches respectively provided in the plurality of wiring members, and a control unit which controls on/off timing of each of the plurality of switches.

Abstract: According to one embodiment, an electronic apparatus includes a connector, power circuit, and controller. The connector is connectable to a first or second external device. The connector includes a first contact configured to receive a first signal from the first external device or a second signal from the second external device. The second signal is different from the first signal and configured to control power inside the electronic apparatus. The power circuit is configured to generate power inside the electronic apparatus using voltage from the first external device or the second external device. The controller is configured to supply a control signal based on the second signal to the power circuit when the first contact receives the second signal.

Abstract: According to one embodiment, an electronic apparatus includes a connector, power circuit, and controller. The connector is connectable to a first or second external device. The connector includes a first contact configured to receive a first signal from the first external device or a second signal from the second external device. The second signal is different from the first signal and configured to control power inside the electronic apparatus. The power circuit is configured to generate power inside the electronic apparatus using voltage from the first external device or the second external device. The controller is configured to supply a control signal based on the second signal to the power circuit when the first contact receives the second signal.

Abstract: A magnetic disk drive includes a switching regulator configured to generate an output voltage, and a magnetic disk control unit that receives the output voltage as a power supply and performs data write and read operations on a magnetic recording medium. The switching regulator includes a voltage conversion part configured to generate a second voltage by switching a first voltage, a smoothing part configured to smooth the second voltage to thus produce an output voltage, a control part configured to control the switching on the basis of a difference between the output voltage and a reference voltage to thus stabilize the output voltage, and a reference voltage changing part configured to change the reference voltage in accordance with an operation mode of the magnetic disk control unit.

Abstract: The correction method of the present invention includes a step for respectively inputting a same-signal pair composed of two signals each having the same signal waveform to two input lines of a normalization circuit, and then adjusting the difference between the values of the two offset signals added to those two input lines to make the output of the normalization circuit fixed or coincide with a predetermined value. The correction method further includes a step for respectively inputting to the two input lines of the normalization circuit a fixed-ratio-signal pair composed of two signals in which the ratio between the amplitudes of waveforms is fixed, and then adjusting each of the two offset signals added to those two input lines while the difference between the values of the two offset signals is maintained as is, to make the output of the normalization circuit fixed or coincide with a predetermined value.

Abstract: The correction method of the present invention includes a step for respectively inputting a same-signal pair composed of two signals each having the same signal waveform to two input lines of a normalization circuit, and then adjusting the difference between the values of the two offset signals added to those two input lines to make the output of the normalization circuit fixed or coincide with a predetermined value. The correction method further includes a step for respectively inputting to the two input lines of the normalization circuit a fixed-ratio-signal pair composed of two signals in which the ratio between the amplitudes of waveforms is fixed, and then adjusting each of the two offset signals added to those two input lines while the difference between the values of the two offset signals is maintained as is, to make the output of the normalization circuit fixed or coincide with a predetermined value.

Abstract: A constant linear velocity control (CLV control) for controlling a spindle motor so as to set a linear velocity in a track circumferential direction to be constant and a constant angular velocity control (CAV control) for controlling the spindle motor so as to set a rotation of a medium to be constant are switched and controlled for a change in position in the radial direction of the medium of a pickup in accordance with a detection result of the medium loaded. In the switching control, selection information of the CLV control and the CAV control is previously registered in accordance with the kind of medium and the CLV control or the CAV control is selected in accordance with the corresponding selection information obtained from the detection result of the medium.