An accessory device has a test port, an instrument port to connect to an instrument having an operating bandwidth, and one or more configurable signal paths connectable between the test port and the instrument port to convert a signal from the test port having a first frequency range to a signal having a second frequency range different than the first frequency range. A test and measurement system has a test and measurement instrument having an operating bandwidth, and an accessory device. The accessory device has a first instrument port to connect the accessory device to the test and measurement instrument, a test port to connect the accessory device to a device under test, and one or more configurable signal paths connectable between the test port and the instrument port to down-convert a signal from the test port having a first frequency range to a signal having a second frequency range lower than the first frequency range.

A method of calibrating a recloser voltage measurement system. In one example, the recloser voltage measurement system includes a voltage divider and a voltage adjustment circuit. The voltage divider is electrically coupled to a recloser. The voltage adjustment circuit is electrically coupled to an output of the voltage divider. The method includes determining a first voltage measurement at a high voltage input to the recloser. The method also includes determining a second voltage measurement at an output of the voltage adjustment circuit. The method further includes calculating a difference between the first voltage measurement and the second voltage measurement. The method also includes determining a target voltage gain based on the determined difference between the first voltage measurement and the second voltage measurement. The method further includes adjusting a voltage ratio of the voltage divider by setting the voltage adjustment circuit to the target voltage gain.

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.

Systems and methods are described for reporting capacitance of a capacitor of a power backup circuit comprising a plurality of metal-oxide-semiconductor field-effect transistors (MOSFETs). The system may also include a bleeder resistor and a voltage detection circuit. When capacitance monitoring is active, a first MOSFET may be turned off, causing the capacitor to be discharged via the bleeder resistor. After predetermined time intervals, a first drain voltage and a second drain voltage of the first MOSFET may be determined using the voltage detection circuit. The drain voltage readings at the different times may be used to determine the capacitance of the capacitor, which may be used to generate and transmit a report on capacitor performance and status.

Systems and methods are described for reporting capacitance of a capacitor of a power backup circuit comprising a plurality of metal-oxide-semiconductor field-effect transistors (MOSFETs). The system may also include a bleeder resistor and a voltage detection circuit. When capacitance monitoring is active, a first MOSFET may be turned off, causing the capacitor to be discharged via the bleeder resistor. After predetermined time intervals, a first drain voltage and a second drain voltage of the first MOSFET may be determined using the voltage detection circuit. The drain voltage readings at the different times may be used to determine the capacitance of the capacitor, which may be used to generate and transmit a report on capacitor performance and status.

A bidirectional sensor circuit includes a sensing impedance with first and second terminals; a first operational amplifier which non-inverting input is connected to the first terminal and its inverting input is connected to the second terminal; a second operational amplifier with the non-inverting input connected to the second terminal and its inverting input is connected to the first terminal; a first diode with the anode connected to the inverting input of the first operational amplifier and whose cathode is connected to the output of the first operational amplifier; and a second diode with the anode connected to the output of the first operational amplifier and to the cathode of the first diode. The input of the circuit consists of the terminals of the sensing impedance, and the output is at the anode of the second diode and senses a load impedance connected to the first terminal of the sensing impedance.

Voltage measurement calibration methods and junction circuits. In one embodiment, the junction circuit includes a capacitor and a voltage adjustment circuit. The junction circuit is electrically coupled to an output of a capacitive voltage divider circuit. The capacitor is electrically coupled between the output of the capacitive voltage divider circuit and a reference terminal. The voltage adjustment circuit is electrically coupled between the output of the capacitive voltage divider circuit and an output of the junction circuit. The voltage adjustment circuit includes an adjustable impedance component configured to adjust a voltage gain of the voltage adjustment circuit.

A power supply in a test and measurement device includes a stimulus having an output coupled to an amplifier in which an output signal from the stimulus controls an output level of the amplifier. The stimulus may include a Digital to Analog Converter. A measurement circuit detects the output level of the amplifier. The power supply includes an overpulse generator that can be structured to accept a desired amplifier output level, overdrive the stimulus at a first level for a first time period, and drive the stimulus at a second level for a second time period. The measurement circuit determines when the overpulse generator switches from driving the stimulus at the first level to driving the stimulus at the second level. The time period for driving the stimulus at the second level starts as the actual amplifier output level approaches the desired amplifier output level.

A power supply in a test and measurement device includes a stimulus having an output coupled to an amplifier in which an output signal from the stimulus controls an output level of the amplifier. The stimulus may include a Digital to Analog Converter. A measurement circuit detects the output level of the amplifier. The power supply includes an overpulse generator that can be structured to accept a desired amplifier output level, overdrive the stimulus at a first level for a first time period, and drive the stimulus at a second level for a second time period. The measurement circuit determines when the overpulse generator switches from driving the stimulus at the first level to driving the stimulus at the second level. The time period for driving the stimulus at the second level starts as the actual amplifier output level approaches the desired amplifier output level.