33results about How to "Current detection" patented technology

A motor control device selectively turns on or off a drive transistor in-accordance with a PWM control signal Sp, such that a drive current Im supplied to a motor is adjusted. The device also samples and holds a motor current Sm for obtaining a motor current value Ih. With reference to the motor current value Ih, the device protects the motor from an overcurrent. Sampling and holding of the motor current Sm is performed for a sampling and holding time Ts. The sampling and holding time Ts corresponds to a time period between a first point in time when the level of the PWM control signal Sp is switched for turning off the drive transistor and a second point in time that precedes the first point in time by a predetermined period. As a result, the motor current value Ih is detected with high accuracy.

In a switching power supply apparatus for performing a switching control of a power MOS transistor that flows current to a coil and converting input voltage into output voltage, even if there occurs offset voltage in a current sensing operational amplifier, source potential of a current sensing MOS transistor is precisely kept at source potential of a low side power MOS transistor. For example, an offset cancel capacitor is arranged at an inverting input terminal of the current sensing operational amplifier, and voltage in the direction to offset the offset voltage occurring in the operational amplifier is charged to this capacitor.

A current sensor includes a busbar, a case, a connector, and a bare chip having a current detection circuit. The busbar has a crimp terminal at one end, a ring terminal at the other end, and a shunt resistor welded between the crimp and ring terminals. The shunt resistor is encapsulated in the case, and the busbar has an electrode exposed to a sealed inner room of the case. The connector has a connector body unitary with the case and has a connector terminal that is exposed to the inner room at one end and exposed to an outside of the connector body at the other end. The bare chip is arranged in the inner room of the case and wire-bonded to each of the busbar and the connector terminal.

A rechargeable motor-driven ratchet wrench having power-off protection of the present invention includes a motor, a rechargeable battery and a power-off protection device. When the loaded current of the motor exceeds a set default value of a reference circuit, the power-off protection device disconnects the power supply of the rechargeable battery, so as to stop the motor operation. With the circuit design of the power-off protection device, the ratchet wrench can be ensured to provide usage safety and also usage lifespan of the ratchet wrench can be extended.

An information processing apparatus that detects an output from a 3-axis acceleration sensor included in an earphone unit worn by a user while the user is in a still state; monitors the output of the 3-axis acceleration sensor while a nodding gesture is performed by the user; detects a time when an angle of the nodding gesture reaches a maximum; and determines an earphone wearing state based on the output from the 3-axis acceleration sensor in the still state and the output from the 3-axis acceleration sensor at the time of detecting the maximum nodding angle.

A diagnostic system for an automatic transmission is provided in which a microcomputer determines that torque that can drive the driving wheels of the vehicle is not transmitted to an output shaft of the automatic transmission when the vehicle is stopped and the ignition key is operated to the OFF position, and performs forced energization of solenoids of solenoid valves associated with respective friction devices of the transmission, while monitoring current passing through the solenoid valves. If the current monitored does not match the current for energizing any of the solenoids, the microcomputer determines that the corresponding solenoid valve is at fault. Thus, the diagnostic system appropriately determines the presence of a fault of each solenoid valve for controlling the hydraulic pressure to each friction device, with increased flexibility and freedom.

A remotely monitorable multi-port charging device has a circuit board provided with plural current-detecting elements and a processing unit. A charging portion having plural connecting ports is for connecting and charging multiple electronic devices. The connecting ports are electrically connected the current-detecting elements. A transmission unit is electrically connected to the circuit board. The current-detecting elements serve to detect charging currents of the electronic devices and generate detection signals. The transmission unit receives detection signals, and transmits the signals through wired or wireless transmission to a remote monitoring station. The processing unit performs remote control through the transmission unit, and switch charging states of the electronic devices at the connecting ports. The charging states include a fast charging mode, a slow charging mode, an adjustment mode, a power-saving mode and a mis-connection mode. Thereby, the multi-port charging device can manage all the connected electronic devices rapidly and effectively.

A current detection apparatus includes a current detection section that detects charging current and discharging current of the car driving battery, a level-shift circuit connected to the output-side of the current detection section that shifts the output of the current detection section, and an A / D converter connected to the output-side of the level-shift circuit. The level-shift circuit shifts the current detection section output signal to unbalance the maximum discharging current and maximum charging current that can be detected.

A semiconductor device capable of detecting a minute current with high accuracy is provided. The semiconductor device includes a first circuit, a second circuit, a first transistor, and a second transistor. A first analog signal is input to the first circuit via the first transistor. A second analog signal is input to the first circuit via the second transistor. The first analog signal includes a value of a first current. The second analog signal includes a value of a second current. The first circuit is capable of converting the first analog signal into a first digital signal. The second circuit is capable of generating a second digital signal based on the first digital signal. The first circuit is capable of converting the second analog signal into a third digital signal based on the second digital signal. The first or second transistor includes an oxide semiconductor in a channel.

A gas concentration detection device includes a pump cell, a sensor cell, a monitor cell, a sensor current detection unit detecting a current outputted by the sensor cell, a monitor current detection unit detecting a current outputted by the monitor cell, a voltage adjustment unit adjusting a pump cell voltage applied to the pump cell, and a sensitivity determination unit determining a gas sensitivity of at least one of the sensor cell or the monitor cell. The voltage adjustment unit changes the pump cell voltage from a target voltage into a detection voltage where the concentration of the residual oxygen supplied to the sensor cell and the monitor cell is increased. The sensitivity determination unit determines the gas sensitivity based on a detection current detected by at least one of the sensor current detection unit or the monitor current detection unit in accordance with the concentration of the residual oxygen.

A circuit protection device and a protection method thereof are provided. The circuit protection device includes a pulse width modulation unit which detects in order for a plurality of current phase of a plurality of transistors. The pulse width modulation unit decides the current phase of the transistors override a first threshold value whether. Then, the pulse width modulation unit sends a control signal to close the transistor that the current phase exceeds the first threshold value, so as to avoid the transistor burn down.