A method is provided for in situ functionality testing of electrical switches using a Functional Reflectometry Test (FRT) of switches on the signal path of electrical circuits in a semiconductor interface. The method includes initiating the functionality testing of the electrical switches in situ, wherein the functionality of the electrical switches is tested while the electrical switches are connected to the Automatic Test Equipment (ATE) and are in-use testing semiconductors. The method also includes conducting full Functional Reflectometry Testing of the electrical switches in situ in an open switch state and a closed switch state to determine whether each of the electrical switches is one of fully functional, stuck closed, and stuck open, wherein testing for each state is performed as a single vector functional test to minimize test time overhead.

A power supply control apparatus detects a failure of a semiconductor switch element in a switching circuit having semiconductor series circuits each having semiconductor switch elements connected in series with reverse polarities. The power supply control apparatus includes a reference resistance value storing unit storing information on a combined resistance value between an input and an output of the switching circuit, a conduction current detection unit configured to detect a current flowing through the switching circuit, a potential difference detection unit configured to detect an input-output potential difference between the input and the output of the switching circuit, a voltage drop calculation unit configured to calculate an assumed voltage drop, a voltage comparison unit configured to compare the input-output potential difference with the assumed voltage drop, and a failure identification unit configured to identify a failure of the semiconductor switch element.

A switch assembly configured to determine when input received from a switch is caused by proper actuation of the switch and should be accepted, or is caused instead by a fault in the switch or in the intervening circuitry and should be ignored and/or reported. The switch assembly optionally includes a logic circuit that is electrically connected to the switch. The logic circuit may provide power to the switch, for example, as a time varying signal, which may then be presented to the logic circuit as input when the switch is properly actuated. The logic circuit may then compare the input from the switch with the signal sent to the switch to determine if a fault is present, or if the switch is operating properly.

A switch detection circuit includes a controller, a first DC isolation module, a second DC isolation module, and a signal conditioning module connected to the controller. The controller is connected to a first end of an external switch via the first DC isolation module and the signal conditioning module is connected to a second end of the external switch via the second DC isolation module. The controller is configured to output a pulse signal, and transmit the pulse signal to the second DC isolation module via the first DC isolation module and the external switch. As a current flowing out from the second DC isolation module, the signal conditioning module outputs a feedback signal to the controller and the controller counts according to the feedback signal and detects the working state of the external switch according to the count value.

Ground-fault circuit interrupter positioned between energy controlled supply circuit and load circuit which includes fault detection circuit that senses ground path current leakage to the load circuit, fault processing circuit that detects presence of fault and generates fault output signal when fault detected, and control circuit switch connected to fault processing signal output, wherein control circuit switch is opened by presence of fault output signal, thus isolating load circuit from supply circuit. Preferably fault processing circuit and control circuit are optically linked, such that when fault is detected, control circuit switch is opened by optical fault output signal, thus isolating load circuit from the supply circuit. Circuit interrupter may couple another circuit interrupter via power distribution control unit, optionally manageable remotely via automated control interface.

A short circuit detection circuit includes a current terminal, a sense resistor, an amplifier, and a resistor-capacitor ladder. The sense resistor is coupled to the current terminal, and is configured to develop a sense voltage proportional to a current through the current terminal. The amplifier is coupled to the sense resistor, and is configured to generate a scaled current proportional to the sense voltage. The resistor-capacitor ladder is coupled to the amplifier, and is configured to generate a measurement voltage that represents a surface temperature rise due to the current through the current terminal.

A testing device including a main housing, and a probe housing, wherein the probe housing is rotatably coupled to the main housing. The testing device further includes a first test probe and a second test probe. The first test probe may be configured to be inserted into an alternating-current receptacle. The second test probe is coupled to the probe housing. The second test probe may be configured to be inserted into a universal serial bus receptacle.

An apparatus and methods to operate the same to provide fast fault-detection on power semiconductor devices such as power transistors are disclosed. In some embodiment, a desaturation based fault-detection circuit for a power transistor is provided. The fault-detection circuit has an adaptable blanking time and a disconnect switch in the blanking mechanism that allow for quick enabling of fault-detection mechanisms to achieve fast fault detection times on power semiconductor devices.

Circuit test devices and methods are provided. The method includes measuring a voltage between first and second conductor points (CPs) of a circuit under test (CUT), and determining if the measured voltage is less than a low voltage threshold value (LVTV) indicative of electrical continuity (EC) between the first and second CPs. In response to determining that the measured voltage is less than the LVTV, the method includes: transmitting a test signal (TS) to the first or second CP, and determining if the test signal is received after being transmitted. In response to determining that the TS is received, a presence of EC between the first and second conductor points is reported, and in response to determining that the TS is not received, absence of EC between the first and second CPs, or a lack of electrical contact between the VMC and the first and/or second CP(s), is reported.

A power conversion device including a switching element includes: a temperature change estimation unit estimating temperature change in a semiconductor chip containing the switching element; a number calculator calculating the number of power cycles to fracture of the semiconductor chip due to power cycles; and a degradation degree calculator computing a degree of degradation of the semiconductor chip caused by the power cycles. The temperature change estimation unit calculates a maximum value and a minimum value of temperature of the semiconductor chip in one power cycle based on a first threshold of temperature fall allowed when it is determined that the temperature of the semiconductor chip is rising, and a second threshold of temperature rise allowed when it is determined that the temperature of the semiconductor chip is falling. The number calculator calculates the number of power cycles to fracture based on the maximum value and the minimum value.