The present disclosure relates to high-voltage circuits. The teachings thereof may be embodied in a circuit apparatus for detecting a state of an interlock loop monitoring a high-voltage component. The apparatus may include a power connection to a voltage source; a ground connection; a positive connection to a line end of the electrical interlock loop; a negative connection to a second line end of the interlock loop; a measuring arrangement for a voltage potential at the negative connection when two mutually different currents flow from the power connection via the negative connection to the ground connection; and a detector arrangement comparing the two potential measurements at the two respective currents with two predefined potential reference values and ascertaining, based on the comparison results of the comparison unit, whether the negative connection is electrically short-circuited with the positive connection, the power connection, or the ground connection, or with none of these connections.

The present disclosure relates to high-voltage circuits. The teachings thereof may be embodied in a circuit apparatus for detecting a state of an interlock loop monitoring a high-voltage component. The apparatus may include a power connection to a voltage source; a ground connection; a positive connection to a line end of the electrical interlock loop; a negative connection to a second line end of the interlock loop; a measuring arrangement for a voltage potential at the negative connection when two mutually different currents flow from the power connection via the negative connection to the ground connection; and a detector arrangement comparing the two potential measurements at the two respective currents with two predefined potential reference values and ascertaining, based on the comparison results of the comparison unit, whether the negative connection is electrically short-circuited with the positive connection, the power connection, or the ground connection, or with none of these connections.

HVAC components having improved efficiency are described. In one embodiment, excessive sleep current draw in a battery-powered device having a microcontroller is detected by measuring a voltage drop across a MOSFET device coupled in a forward-conducting orientation in series between the battery and the microcontroller, causing a transistor to conduct when the voltage drop exceeds a predetermined threshold to generate a first trigger signal, integrating the first trigger signal to generate a second trigger signal, and generating an interrupt to the microcontroller. In another embodiment, a battery-saving method of operating an HVAC component includes maintaining the HVAC device in the sleep mode, receiving a user input to wake the device, transmitting a data request and returning the HVAC component to the sleep mode, waking up the HVAC device to poll an adjacent network node storing a cached response, displaying the response, and returning the HVAC device to sleep.

HVAC components having improved efficiency are described. In one embodiment, excessive sleep current draw in a battery-powered device having a microcontroller is detected by measuring a voltage drop across a MOSFET device coupled in a forward-conducting orientation in series between the battery and the microcontroller, causing a transistor to conduct when the voltage drop exceeds a predetermined threshold to generate a first trigger signal, integrating the first trigger signal to generate a second trigger signal, and generating an interrupt to the microcontroller. In another embodiment, a battery-saving method of operating an HVAC component includes maintaining the HVAC device in the sleep mode, receiving a user input to wake the device, transmitting a data request and returning the HVAC component to the sleep mode, waking up the HVAC device to poll an adjacent network node storing a cached response, displaying the response, and returning the HVAC device to sleep.

Non-ideal diodes have a non-zero resistance across a PN junction when the junction is forward biased. When a diode comprising a power supply has a voltage drop across the junction that exceeds a predetermined threshold, the threshold-exceeding voltage drop trips a comparator, the output of which controls a switch between a power supply and a load.

Non-ideal diodes have a non-zero resistance across a PN junction when the junction is forward biased. When a diode comprising a power supply has a voltage drop across the junction that exceeds a predetermined threshold, the threshold-exceeding voltage drop trips a comparator, the output of which controls a switch between a power supply and a load.

An apparatus and method for greatly increasing power line surge/transient resistance of power semiconductors in inductive heating equipment, in which a sample of the instantaneous line voltage or its rectified equivalent is applied to a comparator input terminal, and a reference voltage corresponding to a predetermined surge shutdown voltage is applied to an opposite comparator input, such that comparator output changes state in response to the predetermined surge shutdown voltage, and is functionally connected to gate drive circuitry to disable gate drive circuitry for the duration of the surge/transient.

An apparatus and method for greatly increasing power line surge/transient resistance of power semiconductors in inductive heating equipment, in which a sample of the instantaneous line voltage or its rectified equivalent is applied to a comparator input terminal, and a reference voltage corresponding to a predetermined surge shutdown voltage is applied to an opposite comparator input, such that comparator output changes state in response to the predetermined surge shutdown voltage, and is functionally connected to gate drive circuitry to disable gate drive circuitry for the duration of the surge/transient.

When using DC power supplies, turning off switches and unplugging from sockets can result in arc discharge, and when arc discharge occurs, heat is generated, which can cause damage to contacts, wiring of disconnection points to melt, and fires. In order to solve this problem, an object is to prevent inrush current when connecting a power supply, detect arc discharge generated when disconnecting direct current, and stop arc discharge over a short period of time. All of the loads that are connected to a DC power supply are equipped with a soft-start function that gradually and smoothly increases current so as to prevent current from flowing suddenly when connected to a power supply, and if a sudden drop in the power supply voltage is detected, an arc discharge is deemed to have occurred, and the flow of current from the power supply to the load is cut off immediately.

A controller configured to detect fault conditions in a circuit that operates an electrical-load includes a gate-driver and a voltage-detector. The gate-driver is configured to control a gate-current to a switching-device. The gate-current is controlled such that the switching-device is operated in a linear-state when the switching-device transitions from an on-state to an off-state. The voltage-detector is configured to determine a voltage-drop across the switching-device. The controller is configured to indicate a no-fault condition when the voltage-drop is greater than a voltage-threshold for more time than a no-fault interval after the switching device is operated from the on-state to the linear-state.