Yamaha Corporation

Norihiro Kawagishi

Yasuhiko Sekimoto

Katsuya Hirano

Nobuaki H Tsuji

Toshio Maejima

A current sensor includes an element substrate that has a first surface facing a wire to which electric current to be measured is supplied and a second surface positioned on the opposite side of the first surface; a pair of sloping surfaces that are formed mutually juxtaposed in the element substrate so as to have slope angles by which their mutual spacing gradually decreases in a first direction approximately orthogonal with the first surface heading from the first surface to the second surface; a pair of magnetism detecting elements that are respectively attached to the pair of sloping surfaces formed in the element substrate; and external connection terminals that are respectively connected to the pair of magnetism detecting elements and that extend in a second direction that is the opposite direction of the first direction, in which the sensitivity directions of the pair of magnetism detecting elements are respectively set so as to slope along the pair of sloping surfaces.

Current sensor and current measuring device

A current detection circuit includes a coil that is constituted by a metal wiring formed on a semiconductor substrate, a resistor that is provided in a position near the coil on the semiconductor substrate, constituted by a metal wiring formed on the semiconductor substrate, which is made of a metal material being same as that of the coil, and arranged so as to prevent any magnetic field from being generated due to a current flowing in the resistor, an output circuit that outputs currents in accordance with a resistance ratio between the coil and the resistor to the coil and the resistor correspondingly through a common terminal, and a detection circuit that detects the current flowing in the resistor to thereby detect the current flowing in the coil.

Current detection circuit and magnetic detection device provided with same

An audio output amplifier includes a plurality of amplification circuits that drive a plurality of electroacoustic conversion devices, respectively. Each of the plurality of amplification circuits includes a current detection resistance that is provided between a path of a current which is supplied to the corresponding electroacoustic conversion device; and a current controller that generates a voltage between both ends of the current detection resistance, the voltage being proportional to a voltage value of an audio input signal supplied to the corresponding amplification circuit.

Audio output amplifier

A voltage generation circuit includes a voltage detection circuit that generates a detection voltage according to an output voltage, a reference voltage generation circuit that generates a reference voltage which changes periodically, a comparison circuit that generates a control signal according to a result of a comparison between the detection voltage and the reference voltage, wherein control pulses each having a pulse width according to the detection voltage are sequentially appeared in the control signal, and a driving pulse generation circuit that generates a driving pulse corresponding to the control pulse and supplies the generated driving pulse to a transistor connected to a DC power source when the pulse width of the control pulse exceeds a predetermined width, and stops generating the driving pulse when the pulse width of the control pulse becomes smaller than the predetermined width.

Growing community of inventors

Hamamatsu, Japan

Norihiro Kawagishi