The power supply control device includes a logic circuit for generating a pseudo switch voltage simulating a behavior of a switch voltage generated in the switch output stage, a filter unit that receives input of the pseudo switch voltage and the output voltage or a feedback voltage corresponding to the output voltage and generates a current sense signal simulating a behavior of the inductor current, and a feedback control unit that performs output feedback control of the switch output stage by using the current sense signal.

The power supply control device includes a logic circuit for generating a pseudo switch voltage simulating a behavior of a switch voltage generated in the switch output stage, a filter unit that receives input of the pseudo switch voltage and the output voltage or a feedback voltage corresponding to the output voltage and generates a current sense signal simulating a behavior of the inductor current, and a feedback control unit that performs output feedback control of the switch output stage by using the current sense signal.

A safety device for an automotive EMI filter that is connected in series with a filtering capacitor. The safety device has normally a low impedance and does not alter the functioning of the filter, but it is configured to present an increased inductance in the event of a discharge. The device reduces the discharge current that can be accidentally conducted through a human body.

A safety device for an automotive EMI filter that is connected in series with a filtering capacitor. The safety device has normally a low impedance and does not alter the functioning of the filter, but it is configured to present an increased inductance in the event of a discharge. The device reduces the discharge current that can be accidentally conducted through a human body.

One example includes a device that is comprised of a pre-power amplifier, a power amplifier, a signal path, and a dynamic bias circuit. The pre-power amplifier amplifies an input signal and outputs a first amplified signal. The power amplifier receives the first amplified signal and amplifies the first amplified signal based on a dynamic bias signal to produce a second amplified signal at an output thereof. The signal path is coupled between an output of the pre-power amplifier and an input of the power amplifier. The dynamic bias circuit monitors the first amplified signal, generates the dynamic bias signal, and outputs the dynamic bias into the signal path.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

According to one embodiment, a drive circuit includes a first circuit part. The first circuit part includes a first detecting part, a second detecting part, a first circuit, and a second circuit. The first detecting part is configured to detect a first piezoelectric element current flowing in a first piezoelectric element, and output a first detection signal corresponding to the first piezoelectric element current. The second detecting part is configured to detect a first capacitance element current flowing in a first capacitance element, and output a second detection signal corresponding to the first capacitance element current. The first circuit includes a first input terminal and a second input terminal. The first circuit is configured to apply a first drive signal to the first piezoelectric element and the first capacitance element. The second circuit is configured to supply a first differential signal to the second input terminal.

According to one embodiment, a drive circuit includes a first circuit part. The first circuit part includes a first detecting part, a second detecting part, a first circuit, and a second circuit. The first detecting part is configured to detect a first piezoelectric element current flowing in a first piezoelectric element, and output a first detection signal corresponding to the first piezoelectric element current. The second detecting part is configured to detect a first capacitance element current flowing in a first capacitance element, and output a second detection signal corresponding to the first capacitance element current. The first circuit includes a first input terminal and a second input terminal. The first circuit is configured to apply a first drive signal to the first piezoelectric element and the first capacitance element. The second circuit is configured to supply a first differential signal to the second input terminal.

A noise filter that can be miniaturized is provided. A noise filter includes a terminal fitting, a board, a coil mounted on the board, and an electronic component mounted on the board. The terminal fitting includes a terminal body electrically connected to an external device, a coil connection part electrically connected to the coil through a lead wire, and a board connection part electrically connected to the board. The coil connection part caulks the lead wire.