The embodiments described herein provide systems and methods for determining the health status of a sensed switch. In general, the embodiments described herein determine a measure of a health status of the sensed switch by comparing a voltage on the sensed switch, ascertaining a first comparator state under one test condition and ascertaining a second comparator state under a second test condition. The first comparator state and the second comparator state are and then compared to determine the measure of the health status of the sensed switch.

Devices and methods are provided, which detect a short circuit condition related to a semiconductor switch. A short circuit condition may be determined when a control signal of the switch exceeds a first reference, and a change of load current of the switch exceeds a second reference.

A test measurement system configured to be applied or otherwise coupled to an energized low-voltage receptacle or to live terminals of a feeder/branch circuit to detect the presence of potentially hazardous conditions. The test measurement system can be configured to indicate to a user if a ground-fault, which could occur at a load supplied by that energized low-voltage receptacle or live terminals of a feeder/branch circuit, would cause unsafe touch potentials to an individual.

Devices and methods are provided, which detect a short circuit condition related to a semiconductor switch. A short circuit condition may be determined when a control signal of the switch exceeds a first reference, and a change of load current of the switch exceeds a second reference.

A functional safety system with high reliability is provided. The functional safety system includes power source apparatuses VS1 and VS2, voltage monitoring apparatuses VM1 and VM2, semiconductor devices SC1 and SC2, interruption circuits IN1 and IN2, and a motor MT. A the voltage converting circuit DA1 of the voltage monitoring apparatus VM1 generates a detected voltage VA1 from a power source voltage VDD1 on the basis of a switching signal VC1, and a voltage converting circuit DA2 of the voltage monitoring apparatus VM1 generates a detected voltage VA2 from the power source voltage VDD1 on the basis of a switching signal VC1.

A switch-operated therapeutic agent delivery device. Embodiments of the operated therapeutic agent delivery device my include a switch that can be operated by a user, a device controller connected to the switch through a switch input where the device can actuate the device when certain predetermined conditions are met, following performance of both a digital switch validation test and an analog switch validation test. The switch operated therapeutic agent delivery device may have two parts, which are assembled by a user prior to use. These devices may be configured to determine if a current is present between the anode and cathode when drug is not intended to be delivered by the device. These devices may indirectly control and/or monitor the applied current without directly measuring from the cathode of the patient terminal.

A residual-current-operated protective arrangement includes a residual-current-operated protective device that has a core and an evaluation coil. A control device is provided that has a detection unit for detecting an electric current flowing through the evaluation coil. The residual-current-operated protective arrangement has a test winding that is inductively coupled to the evaluation coil via the core and the control device has a testing unit for impressing a predetermined test current into the test winding.

A device for monitoring at least three battery cells connected in series. The device includes, for each battery cell, a measuring circuit associated with the battery cell, which measuring circuit has an electrical load and can be switched by a controllable switching element such that the electrical load can be connected into a path parallel to the battery cell associated with the measuring circuit. A control unit that is designed to switch a first measuring circuit, which is associated with the first battery cell, and a third measuring circuit, which is associated with the third battery cell, such that the electrical loads of the two measuring circuits are each connected into the path parallel to the battery cell associated with the respective measuring circuit, and to ascertain whether the switching element of the first measuring circuit is switching correctly.

A load control device includes an energization circuit unit connected between a power source and a load and configured to switch ON and OFF of energization of the load, a failure detection unit connected to a downstream side of the energization circuit unit, a current interruption unit connected to an upstream side of the energization circuit unit and configured to interrupt supply of current of the power source to the energization circuit unit based on an input from the failure detection unit, and a control unit configured to supply an ON-OFF control signal to the energization circuit unit. The energization circuit unit includes a first semiconductor switch and a second semiconductor switch which are connected in parallel to each other The control unit supplies a common ON-OFF control signal to the first semiconductor switch and the second semiconductor switch.

The present invention relates to switching element protection of a BLDC motor, such as used with a power tool. The present invention checks each switching element of a power stage individually for a short circuit when a trigger of the tool is actuated. Each switching element is turned ON for a period of time (such as 1-5 microseconds, for example), current flowing through the half-bridge or the full power stage is measured, and that switching element is turned OFF. When the current is greater than or equal to a threshold (such as 5 A, for example), the controller stops and indicates a fault condition. By testing each switching element in order, the controller is able to determine whether the shorted switching element is the opposite one in the half-bridge being tested.