In one implementation, a circuit can include a reference pin and an operational amplifier that can include an output pin, an inverting input pin and a non-inverting input pin. The inverting input pin can be electrically coupled to the output pin via a first impedance and to the reference pin via a second impedance. The non-inverting input pin can be electrically coupled to the reference pin via a third impedance and can be configured to receive a detection signal. The reference pin can be configured to receive a detection reference signal associated with the detection signal.

A circuit structure for testing through silicon vias (TSVs) in a 3D IC, including a TSV area with multiple TSVs formed therein, and a switch circuit with multiple column lines and row lines forming an addressable test array, wherein two ends of each TSV are connected respectively with a column line and a row line. The switch circuit applies test voltage signals through one of the row lines to the TSVs in the same row and receives current signals flowing through the TSVs in the row from the columns lines, or the switch circuit applies test voltage signals through one of the column lines to the TSVs in the same column and receives current signals flowing through the TSVs in the column from the row lines.

A current detection apparatus includes a voltage detector, a candidate voltage generator, a temperature detector and a correction voltage selector. The voltage detector includes an output terminal for outputting a detected voltage according to a load current. The candidate voltage generator includes correction resistors connected in series and connecting the output terminal and a ground. The candidate voltage generator generates candidate voltages at respective sections across the corresponding correction resistors. The temperature detector detects a temperature of a semiconductor switch. The correction voltage selector selects one of the candidate voltages as a corrected voltage. The one of the candidate voltages is weighted with corresponding one of the corrected magnification scales corresponding to an on-resistance of the semiconductor switch at the measured temperature. The corrected voltage indicates a corrected current value with correction of the load current according to the measured temperature.

A current detection apparatus includes a voltage detector, a candidate voltage generator, a temperature detector and a correction voltage selector. The voltage detector includes an output terminal for outputting a detected voltage according to a load current. The candidate voltage generator includes correction resistors connected in series and connecting the output terminal and a ground. The candidate voltage generator generates candidate voltages at respective sections across the corresponding correction resistors. The temperature detector detects a temperature of a semiconductor switch. The correction voltage selector selects one of the candidate voltages as a corrected voltage. The one of the candidate voltages is weighted with corresponding one of the corrected magnification scales corresponding to an on-resistance of the semiconductor switch at the measured temperature. The corrected voltage indicates a corrected current value with correction of the load current according to the measured temperature.

A monitor can be installed in the terminal block having a monitor access opening. The installed monitor allows for current measurement without having to disconnect a wire from the terminal block. Similar monitors can measure voltage, detect ground loops, and provide continuous readings of circuit parameters. Embodiments can positively hold probe tips, transmit data over wires, or transmit data wirelessly. Make-before-break monitors allow parameters to be measured without ever breaking the monitored circuit. Break-before-make monitors allow the monitored circuit to be interrupted and then reconnected with a monitor in place.

A monitor can be installed in the terminal block having a monitor access opening. The installed monitor allows for current measurement without having to disconnect a wire from the terminal block. Similar monitors can measure voltage, detect ground loops, and provide continuous readings of circuit parameters. Embodiments can positively hold probe tips, transmit data over wires, or transmit data wirelessly. Make-before-break monitors allow parameters to be measured without ever breaking the monitored circuit. Break-before-make monitors allow the monitored circuit to be interrupted and then reconnected with a monitor in place.

A system for the verification of the absence of voltage includes a first impedance, an amplitude limiter electrically connected to the first impedance, a second impedance electrically connected to the first impedance and the amplitude limiter, a varactor circuit electrically connected to the second impedance, an isolation capacitor electrically connected to the second impedance and varactor circuit, an envelope circuit with a voltage detection circuit connected to the isolation circuit via a buffer, and an RF oscillator. The amplitude limiter configured to limit the voltage applied to the varactor circuit. The RF oscillator configured to interact with the varactor circuit in order to create a modulated circuit for the buffer and envelope circuit. The envelope circuit is configured to demodulate the signal for the voltage detection circuit.

An installation test system has a control device and one or more hand-held test devices. The control device and the one or more hand-held devices are in wireless communication via respective communication systems. The control device performs typical pre-power tests including insulation testing and ground testing. There is at least one hand-held device dedicated to testing for residual current in circuit breakers and another hand-held device dedicated to testing for loop impedance. The control device records all test data and stores data in storage.

An installation test system has a control device and one or more hand-held test devices. The control device and the one or more hand-held devices are in wireless communication via respective communication systems. The control device performs typical pre-power tests including insulation testing and ground testing. There is at least one hand-held device dedicated to testing for residual current in circuit breakers and another hand-held device dedicated to testing for loop impedance. The control device records all test data and stores data in storage.

Provided is an electronic apparatus that can prevent erroneous detection of a sensor output due to an AC line noise. A power supply circuit includes a noise filter, input rectifying smoothing circuit, converter circuit, and output smoothing circuit. The input rectifying smoothing circuit rectifies an input AC voltage passed through the noise filter to a pulsating flow and then smooth it. The converter circuit converts a DC voltage rectified and smoothed into a desired output voltage. The output smoothing circuit smoothes the convert output voltage to supply it to a control part. The noise determination part detects a noise that could not have been removed by the noise filter, as an AC line noise. The control part invalidates a detection signal outputted from the sensor for a previously set invalid period from the moment the AC line noise has been detected.