An apparatus includes a control circuit that includes a configuration register and configured to receive a configuration setting across an external bus. The configuration setting encodes a first voltage state for the apparatus. The control circuit includes an input configured to be coupled to an external electrical device. The control circuit is configured to determine a value of the external device that maps to a second voltage state for the apparatus. The control logic is configured to transition the apparatus to a safe mode upon a determination that the first voltage state does not match the second voltage state.

An apparatus includes a control circuit that includes a configuration register and configured to receive a configuration setting across an external bus. The configuration setting encodes a first voltage state for the apparatus. The control circuit includes an input configured to be coupled to an external electrical device. The control circuit is configured to determine a value of the external device that maps to a second voltage state for the apparatus. The control logic is configured to transition the apparatus to a safe mode upon a determination that the first voltage state does not match the second voltage state.

A controller for a brushless direct-current motor having an upstream converter, which has a half-bridge having a pair of switching means for each phase winding of the motor, includes a measuring device or has a signal connection to a measuring device. The measuring device is associated with a half-bridge and by means of the measuring device, the induced voltage, the counterelectromotive force of a phase winding, can be detected for rotor position detection in the current-free state, for which purpose the controller, in an operating mode that causes the braking and in which the switching means cause a short circuit of the phase windings, briefly opens the switching means associated with the measuring device in order to determine a rotor motion.

When the current flowing through each electric terminal of an AC motor 21 reaches the vicinity of zero, an operation putting the electric terminals of the AC motor 21 into an opened state, or putting an electric terminal into a conductive state via a reflux diode inside an inverter 11, is carried out. Herein, as an operation such that the current flowing through each electric terminal reaches the vicinity of zero, the electric terminals are short-circuited by all upper arm or lower arm switching elements of the inverter 11 being turned on. By so doing, a flow of electromagnetic energy of a reactance component of the AC motor 21, from the AC motor 21 into the inverter 11 side when the drive of the inverter 11 is stopped, is prevented or suppressed. As a result of this, an overvoltage or overcurrent is prevented.

Even when an overvoltage suppression circuit is not formed due to failure of an overvoltage suppression switch, overvoltage application to semiconductors and a filter capacitor is prevented. A control unit controls the overvoltage suppression circuit to short-circuit the filter capacitor when the voltage thereacross exceeds a predetermined value. Then when non-operation of the overvoltage suppression circuit is detected, the control unit opens an AC breaker and AC switch, and closes a charging switch. Thereafter, the control unit turns ON the converter element (or converter element) connecting to the filter capacitor terminal (or terminal) and a charging resistor, and turns ON converter element (or converter element) connecting to terminal (or terminal) of filter capacitor and connecting to the terminal of the transformer not connected to charging resistor.

Even when an overvoltage suppression circuit is not formed due to failure of an overvoltage suppression switch, overvoltage application to semiconductors and a filter capacitor is prevented. A control unit controls the overvoltage suppression circuit to short-circuit the filter capacitor when the voltage thereacross exceeds a predetermined value. Then when non-operation of the overvoltage suppression circuit is detected, the control unit opens an AC breaker and AC switch, and closes a charging switch. Thereafter, the control unit turns ON the converter element (or converter element) connecting to the filter capacitor terminal (or terminal) and a charging resistor, and turns ON converter element (or converter element) connecting to terminal (or terminal) of filter capacitor and connecting to the terminal of the transformer not connected to charging resistor.

An air conditioner and a compressor protection circuit thereof are provided. When overcurrent occurs in a phase current of a compressor, an overcurrent level signal is output by a voltage comparison module, and is latched and output to an intelligent power module by a signal latching module, and the intelligent power module shuts off the output of the phase current according to the overcurrent level signal, so as to achieve the overcurrent protection of the compressor; and subsequently, a conventional level signal is output to the signal latching module by the voltage comparison module, the signal latching module keeps outputting the overcurrent level signal, and outputs the conventional level signal until a latching cancel signal output by a signal processing circuit is received, so that the intelligent power module starts the output of the phase current, thereby enabling the compressor to normally operate.

An air conditioner and a compressor protection circuit thereof are provided. When overcurrent occurs in a phase current of a compressor, an overcurrent level signal is output by a voltage comparison module, and is latched and output to an intelligent power module by a signal latching module, and the intelligent power module shuts off the output of the phase current according to the overcurrent level signal, so as to achieve the overcurrent protection of the compressor; and subsequently, a conventional level signal is output to the signal latching module by the voltage comparison module, the signal latching module keeps outputting the overcurrent level signal, and outputs the conventional level signal until a latching cancel signal output by a signal processing circuit is received, so that the intelligent power module starts the output of the phase current, thereby enabling the compressor to normally operate.

A drive controller that controls a drive of a motor. The drive controller performs a collision force moderation control during a motor start time, during which a collision force in a collision between a shaft outwall with an impeller hole inwall for a positioning is moderated, by changing a power supply at a stage transition time of transiting from a position detection to a position determination. The maximum value of a first output value during a position detection time is set to be greater than a first threshold that at least causes a rotation number of the motor to yield a detectable induction voltage. A second output value during a position determination time is set to be lower than a second threshold that causes a wear or a breakage of an impeller by the collision force.

An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit is coupled to an input terminal for receiving an input voltage. The overvoltage protection circuit comprises a switch circuit, a controller, and a comparing unit. When the input voltage is greater than a first voltage, a discharging mechanism is forced to start so as to suppress a voltage spike. When the input voltage is less than a second voltage, the discharging mechanism is closed so as to operate normally.