A power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier. First and second primary switches in series with first and second primary windings, respectively, are turned on for a fixed duty cycle, each for approximately one half of the switching cycle. Switched transition times are short relative to the on-state and off-state times of the controlled rectifiers. The control inputs to the controlled rectifiers are cross-coupled from opposite secondary transformer windings.

High efficiency power converter

A liquid crystal apparatus comprises a) a liquid crystal device comprising an electrode matrix composed of scanning electrodes and data electrodes, and a ferroelectric liquid crystal; and b) a driving means. The driving means includes a first drive means for applying a scanning selection signal two or more scanning electrodes apart in one vertical scanning so at to effect in one picture scanning in plural times of vertical scanning, and a second drive means for applying data signals in synchronism with the scanning selection signal.

Liquid crystal apparatus

Provided are a battery state monitoring circuit and a battery device which are capable of inhibiting discharge without enabling an overdischarge cell balance function when an overcurrent detection circuit detects a discharge overcurrent, without the need for an additional terminal of the battery state monitoring circuit. A detection signal of the overcurrent detection circuit is input to each of a communication terminal for overdischarge signal and a communication terminal for overcharge signal included in the battery state monitoring circuit provided on a side of the overcurrent detection circuit. An overdischarge cell balance circuit outputs a cell balance signal when an overdischarge detection signal indicates an overdischarge non-detected state, an overdischarge signal indicates an overdischarge detected state, and an overcharge signal indicates an overcharge non-detected state.

Battery state monitoring circuit and battery device

The present invention is directed to perform fine low-voltage control without largely increasing the circuit layout area in a low-power consumption structure. In the case of shifting a region to a low-speed mode, a system controller outputs a request signal and an enable signal to a power switch controller and a low-power drive circuit, respectively, to turn off a power switch and to perform a control so that the voltage level of a virtual reference potential becomes about 0.2 V to about 0.3V. The region operates on voltages between a power supply voltage and a virtual reference potential, so that it is controlled in the low-speed mode.

Semiconductor Integrated Circuit Device

A battery charge control circuit (10) senses the charge condition of cells in a battery pack (12, 14, 16, 18) using a measurement circuit (51). Upon detection of a single under-voltage cell, the charge control circuit is placed in a sleep mode. Pack sense circuit (240) senses when the battery pack is placed in a charger. If circuit (10) was in a sleep mode, it is awakened. If any cell is measured over-voltage, the status is checked versus the other cells. If all the cells are over-voltage, the battery is considered balanced. If one or more cells are not over-voltage, a control circuit (32) activates a discharge transistor (212, 214, 216, 218), discharging the cell within a hysteresis voltage below the over-voltage limit. Charge balancing of cells is continued until the cells are within a programmable hysteresis voltage of each other.

Circuit and method for battery charge control

A charge/discharge control circuit is provided for an electric power source apparatus in which a service life is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge voltage detection circuit and a control circuit are connected in parallel to a secondary cell which is an electric power source, wherein the control circuit detects a condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal Vs for controlling a power supply to an external equipment and a charge by an external power source and controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the voltage dividing circuit.

Charge/discharge control circuit and chargeable electric power source apparatus

A switching circuit has input terminals, switching MOS transistors, and a control circuit having a control terminal. Diodes are connected between the respective input terminals and the control circuit. When input voltage (V1, V2) are applied to the input terminals, the output terminal is selectively put in either a fixed or a floating state according to the voltage applied to the control terminal.

Switching circuit for selecting an output signal from plural input signals

The voltage regulator of the boosting/lowering type is comprised of a switching regulator block and a series regulator block, which are cascade-connected to each other. One input terminal of an error amplifier of the switching regulator block is connected to a dividing node of bleeder resistors in the series regulator block to constitute a regulative feedback loop effective to improve an efficiency of the voltage regulator.

Cascaded switching and series regulators

PROBLEM TO BE SOLVED: To stop discharge before a switching circuit generates heat and breaks down, by performing discharge control receiving the signals of a circuit which detects two kinds or more of different voltages of overcurrent detecting terminals, and exhibiting a discharge stopping function by an appropriate delay time, against two kinds or more of different load currents. SOLUTION: The reference voltage 111 of a reference voltage circuit 105 is set higher than the reference voltage 112 of a reference voltage circuit 106, and the delay time of a delay circuit 109 is set shorter than that of a delay circuit 110. By performing setting this way, a switching circuit 103 is turned off after the delay time preset by the delay circuit 110, when an overcurrent flows and the voltage of a current sensing resistor 104 is kept higher than the reference voltage 112 and lower than the reference voltage 111. Accordingly, it becomes possible to turn the switching circuit off by a shorter delay time than the switching circuit generates heat and breaks down, even if something abnormal happens and an excessive current flows. COPYRIGHT: (C)1998,JPO

Charge/discharge control circuit.

A power supply circuit for supplying power which may be used to drive a liquid crystal display unit in a multiline addressing scheme, in which drive voltages VH, VL and Vi on the common side of the liquid crystal display unit can satisfy the relationship VH-Vi=Vi-Vt with high accuracy, comprises a switching regulator for generating a first output voltage of a first polarity, a resistor connected to the first switching regulator to divide the first output voltage and produce a divided output voltage, and a second, constant-voltage power supply circuit which includes an error amplifier that inputs the divided output voltage as one of a supply voltage and a reference voltage and which generates a second output voltage opposite in polarity to the first polarity so that a constant relationship is maintained between the first and second output voltages.

Sadashi Shimoda

Papers

Charge/discharge control circuit and chargeable electric power source apparatus

Switching circuit for selecting an output signal from plural input signals

Cascaded switching and series regulators

Charge/discharge control circuit.

Power supply circuit