A method and system to prevent unexpected operation of a motor when the voltage level on a DC bus drops is disclosed. The voltage level on the DC bus is monitored during a run command. When a run is commanded, the processor executes a control routine to determine a desired amplitude and frequency for the output voltage required to control the motor connected to the motor drive. If the desired frequency of the output voltage exceeds a maximum frequency for the measured voltage on the DC bus, as established by parameters stored in the motor drive, the motor drive limits the output frequency to the maximum frequency for the corresponding measured voltage. The motor drive continually monitors the measured voltage present on the DC bus and further reduces the maximum output frequency allowed during the run if the present value of the measured voltage drops below a previously measured value.

A power converter is provided. A driver circuit is connected between a controller circuit and a switch circuit. The switch circuit is connected to an inductor. The inductor is connected in series with a first capacitor and grounded through the first capacitor. A first comparison input terminal of a first comparator is connected to an output terminal between the inductor and the first capacitor. A second comparison input terminal of the first comparator is grounded through a second capacitor. The controller circuit outputs a control signal for controlling the driver circuit to drive the switch circuit according to a comparison signal outputted by the first comparator. A reference current source provides a reference current to the second capacitor. A first terminal of a first resistor is connected to the second capacitor. A second terminal of the first resistor is coupled to a reference potential.

A power supply system includes multiple power supply devices including a first power supply device and a second power supply device that are connected in common to a load. The first power supply device calculates control information for controlling voltage or current to be output to the load and controls the output to the load based on the calculated control information while transmitting the control information to the second power supply device. The second power supply device receives the control information and controls the output to the load based on the received control information while detecting current to be output from its own device to the load and transmitting current information to the first power supply device. The first power supply device receives the current information transmitted from the second power supply device and calculates control information based on the received current information and the current and voltage detected by its own device.

A power distribution monitoring system is provided that can include a number of features. The system can include a plurality of monitoring devices configured to attach to individual conductors on a power grid distribution network. In some embodiments, a monitoring device includes a current sensing element comprising a Rogowski coil. The output of the Rogowski coil can be used by a fault detection circuit to determine if a fault or disturbance occurs on the conductor. Methods of using the monitoring devices are also provided.

A power converter system includes an input rectifier configured to rectify a line power having a line energy and a full-bridge isolating converter comprising a transformer, where the full-bridge isolating converter is configured to generate an isolated output voltage based on the rectified line power, and where the isolated output voltage is electrically isolated from the line energy. The power converter system includes a power controller configured to operate the full-bridge isolating converter to generate the isolated output voltage, determine whether the transformer is operating in a flux walk state based on an electric current of the transformer, and perform a corrective action in response to the transformer operating in the flux walk state.

A method of controlling a power supply in a multi-input power supply system includes retrieving a prior input state flag from a memory of the multi-input power supply system, determining a first dimmer input of the multi-input power supply system based on the prior input state flag, determining whether the first dimmer input is currently valid, and in response to determining that the first dimmer input is not valid, determining whether a second dimmer input of the multi-input power supply system is currently valid, and in response to determining that the second dimmer input is valid, controlling the power supply based on a second input signal received through the second dimmer input.

In a state that a first voltage is applied to a charging member so as to form a surface potential on a region of an image bearing member and a second voltage the same in polarity as the first voltage is applied to a transfer member, a detection unit detects a transfer current in the region of the image bearing member during one rotation of the image hearing member after the region passes through a charging portion, when an absolute value of the surface potential formed on the region immediately before entry into the charging portion is larger than an absolute value of the surface potential formed on the region when it is positioned upstream of a transfer portion and downstream of the charging portion in a rotational direction of the image bearing member.

A frequency variable oscillator generates a clock having a frequency according to a control signal. A reference current source generates a reference current. A path selector distributes the reference current to a first path and a second path in a time-sharing manner in synchronization with the clock. An F/V conversion circuit includes a capacitor connected to the first path, and charges or discharges the capacitor with the reference current and generates a detection voltage. The reference voltage source includes a resistor connected to the second path, and outputs a reference voltage according to a voltage across the resistor. A feedback circuit adjusts a control signal so that the detection voltage approaches the reference voltage.

The present document relates to Single Inductor Dual Input (SIDI) buck power converters. More specifically, a dual input power converter may comprise an inductor, a first high-side switching element, a second high-side switching element, and a low-side switching element. The inductor may be coupled between an intermediate node and an output of the dual input power converter. The first high-side switching element may be coupled between a first input of the dual input power converter and the intermediate node. The second high-side switching element may be coupled between a second input of the dual input power converter and the intermediate node. The low-side switching element may be coupled between the intermediate node and a reference potential.

A power converter system provides adjustable power to a heater and includes an input rectifier and a full-bridge isolating converter. The input rectifier is configured to rectify a line power having a line energy. The full-bridge isolating converter configured to generate an isolated output voltage based on the rectified line power. The isolated output voltage is electrically isolated from the line energy.