To provide a measurement device which allows long-term accurate measurement of voltage without adversely affecting a device under test, by ensuring a predetermined level of resistance to ESD and reducing leakage current. A measurement device includes a probe needle for contacting a device under test, a first FET for detecting voltage of the device under test, and a protection circuit for protecting the first FET from static electricity. The protection circuit includes a second FET having an oxide semiconductor film as a channel formation region.

An electrical circuit protecting an electrical utility meter used in connection with an electrical supply connection having a plurality of phases is disclosed. The circuit includes a plurality of voltage transformers, each of the plurality of voltage transformers electrically connected between one of the plurality of phases of the electrical supply connection and an input power connection of an electrical meter, and an electrical connection of the electrical meter dedicated to a power supply of the electrical meter.

An electrical circuit protecting an electrical utility meter used in connection with an electrical supply connection having a plurality of phases is disclosed. The circuit includes a plurality of voltage transformers, each of the plurality of voltage transformers electrically connected between one of the plurality of phases of the electrical supply connection and an input power connection of an electrical meter, and an electrical connection of the electrical meter dedicated to a power supply of the electrical meter.

A device and method for limiting damage to a semiconductor device under test when the semiconductor device fails during a high current, or high power test is provided. The occurrence of a failure of the device under test is detected, and power applied to the semiconductor device is diverted through a parallel path element upon detection of failure of the semiconductor device.

A detection and protection circuit includes: a comparator, six resistors, and two diodes. A first resistor is connected to a second resistor. The second resistor (30) is grounded. A positive input end, a negative input end, a power supply end, a ground end, and an output end of the comparator are connected to a third resistor, a fourth resistor, a power management device power supply pin, the ground, and a main controller. The other end of the third resistor is connected between the first resistor and the second resistor. The other end of the fourth resistor is connected to the first resistor. A first power supply is connected between the fourth resistor and the first resistor. A fifth resistor is connected to a sixth resistor. The sixth resistor (70) is grounded. The other end of the fifth resistor is connected to the main controller.

A detection and protection circuit includes: a comparator, six resistors, and two diodes. A first resistor is connected to a second resistor. The second resistor (30) is grounded. A positive input end, a negative input end, a power supply end, a ground end, and an output end of the comparator are connected to a third resistor, a fourth resistor, a power management device power supply pin, the ground, and a main controller. The other end of the third resistor is connected between the first resistor and the second resistor. The other end of the fourth resistor is connected to the first resistor. A first power supply is connected between the fourth resistor and the first resistor. A fifth resistor is connected to a sixth resistor. The sixth resistor (70) is grounded. The other end of the fifth resistor is connected to the main controller.

A load zone of a DC system includes a connection interface for supplying the load zone with electrical energy, an electronic switch arranged between the connection interface and a DC bus, and at least two electrical devices connected in parallel to the DC bus. A voltage sensor measures a voltage across a fuse arranged between the DC bus and a respective electrical device. An evaluation unit identifies a defective device of the at least two electrical devices based on a polarity of the voltage measured by the voltage sensor across the fuse. A DC system with such a load zone and an energy source connected to the connection interface of the load zone, as well as a method for operating such load zone or DC system are also disclosed. A device is identified as being defective when the voltage measured across the fuse exceeds a specified limit value.

A load zone of a DC system includes a connection interface for supplying the load zone with electrical energy, an electronic switch arranged between the connection interface and a DC bus, and at least two electrical devices connected in parallel to the DC bus. A voltage sensor measures a voltage across a fuse arranged between the DC bus and a respective electrical device. An evaluation unit identifies a defective device of the at least two electrical devices based on a polarity of the voltage measured by the voltage sensor across the fuse. A DC system with such a load zone and an energy source connected to the connection interface of the load zone, as well as a method for operating such load zone or DC system are also disclosed. A device is identified as being defective when the voltage measured across the fuse exceeds a specified limit value.

Surge protection circuitry includes a pair of series connected diodes sharing a first common terminal that is directly electrically connected to only one of a pair of transmission lines, a pair of series connected Zener diodes, in parallel with the series connected diodes, sharing a second common terminal that is directly electrically connected to only the other of the transmission lines, and a pair of series connected power supplies each configured to reverse bias one of the series connected diodes such that the diodes prevent electrical coupling of the Zener diodes to the transmission lines responsive to a voltage of the signal source being less than a threshold value, and the diodes permit electrical coupling of at least one of the Zener diodes to the transmission lines responsive to the voltage being greater than the threshold value.

Surge protection circuitry includes a pair of series connected diodes sharing a first common terminal that is directly electrically connected to only one of a pair of transmission lines, a pair of series connected Zener diodes, in parallel with the series connected diodes, sharing a second common terminal that is directly electrically connected to only the other of the transmission lines, and a pair of series connected power supplies each configured to reverse bias one of the series connected diodes such that the diodes prevent electrical coupling of the Zener diodes to the transmission lines responsive to a voltage of the signal source being less than a threshold value, and the diodes permit electrical coupling of at least one of the Zener diodes to the transmission lines responsive to the voltage being greater than the threshold value.