Abstract: A trip unit connection tester (10) is arranged to test the electrical connections (12) and (14) between a trip unit (16) and actuator (18) mounted within a circuit breaker (20). Tester (10) includes a power source (64) including a positive lead (68), and a negative lead (70). The positive lead (68) is coupled to a two-loop switch (58). The two loop switch (58) toggles between a first loop (98), and a second loop (100). The first loop (98) includes the power source (64), the two-loop switch (58), and the energy storage element (82) wherein the energy storage element (82) stores energy coming from the power source (64). The second loop (100) includes the two-loop switch (58), and the energy storage element (82), connections (12) and (14), and the actuator (18), wherein energy stored within the energy storage element (82) is released to the actuator (18).

Abstract: The invention relates to a circuit for supplying a consumer (10) with electric energy provided by a battery (11). The battery voltage (Ub) is prevented from falling below a predetermined minimum voltage (Umin) by a regulator (18) which adjusts the battery voltage (Ub) to a predetermined minimum voltage (Umin) by influencing the average amount of energy which is provided to the consumer (10). Preferably, the inventive circuit is used in a motor vehicle.

Abstract: A circuit protects a power conversion system with a feedback control loop from a fault condition. The circuit has an oscillator having an input for generating a signal with a frequency and a timer connected to the oscillator input and to the feedback control loop. The timer disables the oscillator after a period following the opening of the feedback control loop to protect the power conversion system.

Abstract: A switched mode controller for properly handling an under-voltage condition in a power line which includes a current mirror for receiving current from the power line; a reference current source coupled to the current mirror for supplying a reference current; and a power transistor coupled to the reference current source, the power transistor generating a pulse width modulated signal when current from the power line exceeds the reference current, the power transistor being disabled when current from the power line is less than the reference current.

Abstract: In a method and apparatus for power removal from a control circuit of an application circuit where that application circuit, as a result of a triggering event, can create damaging noise in the control circuit, a power supply is provided for the control circuit. Power is supplied from the power supply to the control circuit until initiation of the triggering event. Upon initiation of the triggering event, power flow is stopped to the control circuit for a predetermined time delay sufficient so that after the triggering event has ceased, transient noises which may still be present after the triggering event do not harm the control circuit or produce incorrect operation. At the end of the time delay, power is reconnected to the control circuit. Preferably, the control circuit is a microcontroller connecting to an ignition circuit for firing a gas chamber in a gas powered fastener gun.

Abstract: A method for detecting electrical faulty conditions in a plurality of power devices of a propulsion system is provided. The plurality of power devices is connectable in parallel circuit through a direct current (DC) link to an external DC power source. The method provides a first sequence of actions for determining an electrical short condition in at least one of the power devices upon the power source being connected. The method further provides a second sequence of actions for determining an electrical open condition in a respective one of the plurality of power devices during the occurrence of high current events.

Abstract: The UVLO (undervoltage lockout) circuit provides a very low quiescent current that is independent of supply voltage. The circuit includes a low voltage IPTAT (current proportional to absolute temperature) generator coupled to a comparator 24 wherein a first input of the comparator 24 is coupled to the IPTAT generator in a way that forms a bandgap voltage with respect to ground and a second input of the comparator 24 is coupled to the IPTAT generator in a way that forms a bandgap voltage with respect to a supply node. This makes the quiescent current independent of the supply voltage because there is no voltage divider between the supply node and ground.

Abstract: A protection circuit arranged in a switching power supply system for protecting the switching power supply system is provided. The protection circuit includes a detecting circuit electrically connected to a switching controller of the switching power supply system for providing a trigger signal when a supply voltage drops to an under-voltage level, and a protection circuit electrically connected to the detecting circuit for providing a signal to protect the switching power supply system when the detecting circuit provides the trigger signal to the protection circuit. A method for protecting an switching power supply system is provided. The method includes the steps of detecting that the reference voltage signal disappears when the supply voltage is smaller than a minimum of operating voltage and providing a trigger signal, and providing an protection to protect the switching power supply system in response to the trigger signal.

Abstract: A switched mode controller for properly handling an under-voltage condition in a power line which includes a current mirror for receiving current from the power line; a reference current source coupled to the current mirror for supplying a reference current; and a power transistor coupled to the reference current source, the power transistor generating a pulse width modulated signal when current from the power line exceeds the reference current, the power transistor being disabled when current from the power line is less than the reference current.

Abstract: A trip unit connection tester (10) is arranged to test the electrical connections (12) and (14) between a trip unit (16) and actuator (18) mounted within a circuit breaker (20). Tester (10) includes a power source (64) including a positive lead (68), and a negative lead (70). The positive lead (68) is coupled to a two-loop switch (58). The two loop switch (58) toggles between a first loop (98), and a second loop (100). The first loop (98) includes the power source (64), the two-loop switch (58), and the energy storage element (82) wherein the energy storage element (82) stores energy coming from the power source (64). The second loop (100) includes the two-loop switch (58), and the energy storage element (82), connections (12) and (14), and the actuator (18), wherein energy stored within the energy storage element (82) is released to the actuator (18).

Abstract: A battery disconnect device includes a housing with a trip/sense circuit, a sealed solenoid and two bars. The solenoid includes a spring loaded contactor disposed in a sealed chamber which normally bridges the bars and is constructed to provide a very low resistivity between the bars. When a coil of the solenoid is activated, in response, for example, to a low battery voltage, the contactor moves away from the bars and is kept in an open position by a magnet. The contactor can be closed or returned to the original position by a manual push button or by a close circuit operated from a remote switch. Additionally the contactor may be opened by using a remote button to act as an anti-theft device.

Abstract: A power supply supervisor having a line voltage detector is used to monitor a power supply. A peak detector detects the line voltage by measuring the PWM switching signal in the secondary of the transformer. A logic circuit couples to the peak detector and the under-voltage detector, etc. to generate a power good (PG) signal when the power supply outputs meet the specifications. The logic circuit outputs a FAIL signal to turn off the power supply when an abnormal situation, such as over-voltage, occurs. Furthermore, when AC power is lost or turned off, the logic circuit detects a low line voltage and generates a power-down-warning PG signal before the output voltages are disabled. When an abnormal situation occurs before the low line voltage is detected, the logic circuit latches the power supply in a power off state. If the abnormal situation occurs after the low line voltage is detected, the logic circuit turns off the power outputs, but disables the latch function.

Abstract: An electronic device including a voltage supply source is presented. Included in the electronic device is a low voltage detection circuit that is connected to the voltage supply source. Also, a voltage offset circuit is connected to the low voltage detection circuit. The voltage offset circuit offsets a voltage drop in the low voltage detection circuit that is caused by a voltage transient. Therefore, a false reading is prevented in the low voltage detection circuit.

Abstract: To detect a power supply failure on an intrinsically safe field bus of a manufacturing process control system in an efficient manner there is provided a field device with a discharge protection unit which is connected to a control bus for supply of an operating current from the control bus to the field device. The discharge protection unit inhibits a discharge of energy stored in the field device to the control bus. The field device also comprises a controller unit adapted to control the operation of the field device and being powered with the operating current from the control bus. According to the present invention the discharge protection unit comprises at least two rectifying elements inserted into the current path of the operating current with identical conducting directions and an input signal or an output signal of a selected rectifying element is supplied as interrupt signal to the controller unit for power supply failure detection.

Abstract: A microcontroller with a self-prompting (self-wake-up) device, particularly for use in electrical adjusting drives, having a control device for specifying an active and an inactive operating state to economize on supply power, contains an oscillator for emitting a prompting signal or a clock frequency. This oscillator is a low-frequency, power-saving oscillator. Provided in the microcontroller is a circuit, preferably a disconnectible phase-locking loop, which, from the low frequency of the oscillator, generates a substantially higher clock frequency for microcontroller core. The low-frequency oscillator is also integrated as an original component into the microcontroller. An undervoltage detection, whose output signal is able to be supplied directly to the microcontroller core, indicates undervoltage conditions immediately. Using a time-switch logic which monitors a non-operative time of the microcontroller core, the core is activated again via a prompting circuit.

Abstract: A power-source system includes: a power source; a voltage monitoring unit for monitoring a voltage of the power source to detect that the voltage falls below a consumption-limit level below which the use of the power source is to be limited; a consumption limiting unit for limiting the use of the power source when the voltage falls below the consumption-limit level; and a consumption-limit prohibiting unit for prohibiting the consumption limiting unit from limiting the use of the power source when the voltage of the power source falls below the consumption-limit level because of a momentary voltage fall different from a voltage fall corresponding to a discharge curve of the power source.

Abstract: The presently disclosed method and apparatus provides the sensing of an output voltage of a charge pump without applying a load to the output stage. In the charge pump the voltage change which occurs across a capacitor of a stage of the charge pump when the charge pump transfers charge to the next stage is proportional to the difference between the voltage at the output of the charge pump under load, and the voltage which will be developed at the output of the charge pump with no load. There is an interval in the timing of the charge pump cycle after the first stage capacitor has transferred its charge to a second stage capacitor where the high side of the first capacitor has not yet been connected to the line voltage. During this interval the charge pump undervoltage detection circuit measures the voltage at the high side of the capacitor and compares this measured voltage to a reference voltage.

Abstract: The present invention has the object of providing an overshoot/undershoot prevention device and overshoot/undershoot prevention method that are highly effective against both overshoot and undershoot. The overshoot/undershoot prevention device is provided with an overshoot shaping device that selects the portion of a waveform signal that equals or exceeds an overshoot determining potential when the potential of the waveform signal equals or exceeds the overshoot determining potential, outputs the selected portion as an overshoot waveform, attenuates the overshoot component of the waveform signal, and outputs the result as a shaped waveform in accordance with the time that the overshoot waveform continues.

Abstract: A low voltage cutoff circuit, a method of operating the same and a battery backup system incorporating the low voltage cutoff circuit or the method. In one embodiment, the low voltage cutoff circuit includes: (1) a low voltage monitor coupled between an input and an output of the low voltage cutoff circuit, (2) a cutoff switch, coupled between the input and the output and controlled by the low voltage monitor, that closes to couple the input to the output, the cutoff switch subject to failing closed when a voltage of the input is below a threshold and a load couplable to the output contains a short circuit and (3) a short circuit protection circuit, coupled to the low voltage monitor, that senses when the load contains the short circuit and directs the low voltage monitor to prevent the cutoff switch from closing.

Abstract: An electronic instrument in which erroneous operation after power is applied thereto even in the case where a power source voltage is not quickly raised. Power is generated by a power source such as a thermoelectric conversion device and stored in a secondary battery or charge storage device through a optional boosting circuit. A control circuit and a main circuit are supplied with the power. However, the control circuit has a lower minimum operating voltage than the main circuit. Thus, with the increase in level of the power source voltage, the control circuit starts to operate before the main circuit and outputs a control signal to prevent the main circuit from operating in such a manner that a through current is prevented and the main circuit is prevented from drawing appreciable current from the power source circuit, which would prevent the voltage of the secondary battery or the charge storage device from increasing.

Abstract: The protection circuit for a power supply unit comprises a switching stage, at which at least two output voltages to be monitored are connected, these voltages being isolated from one another by means of resistors. Arranged here in the connection path of the output voltages is a diode, which turns on and thereby triggers the switching stage in the event of a fault, when there is a drop in one of the output voltages. In this way, the switching stage provides information which acts on a control loop of the power supply unit, so that the power supply unit switches off. The protection circuit also includes a passive network with a resistor and a capacitor, which prescribes a time constant, after which the protection circuit permits renewed starting of the power supply unit. The switching stage may be realized, for example, by a transistor stage, which provides the information signal for the event of a fault for the power supply unit when turning on occurs.

Abstract: A switching power supply apparatus comprises a transformer having a primary winding, a secondary winding, and a feedback winding; a switching element connected in series with the primary winding, a controlling circuit provided between a control terminal of the switching element and the feedback winding; a rectifying circuit connected to the secondary winding; and a protecting circuit adapted to stop the switching operation of the switching element in correspondence to an abnormality in voltage produced in the feedback winding and having the opposite polarity to the voltage produced in the feedback winding.

Abstract: An apparatus and method is disclosed for retaining parameter information generated or received in an electronic circuit breaker (10). The electronic circuit breaker (10) includes a controller and is connected in a branch circuit coupled to a power source via a power line and powered by the power source. Upon occurence of a power fault, a control signal responsive to the power fault is generated and coupled to a control input of the circuit breaker. The control signal causes retention of parameter information generated or received in the electronic circuit breaker (10). Means for retaining the data representing parameter information include charging a storage capacitor to a predetermined value corresponding to the parameter information being retained, writing the parameter information being retained to an EEPROM and writing the data containing the parameter information being retained into a Static RAM.

Abstract: An undervoltage circuit breaker has an electromagnet for triggering a switching device and a driver circuit that supplies power to the electromagnet. The driver circuit contains a pulse generator for generating a holding current for the electromagnet and a capacitance dimensioned so that delayed triggering of the electromagnet is possible. Due to the variable pulse duty factor of the pulse generator, the energy content of the capacitance is utilized favorably. An elevated operating voltage can also be selected and therefore a smaller capacitor may be selected to advantage.

Abstract: A switching mode power supply apparatus has a low voltage protection circuit with a simple construction. The apparatus is not actuated or have its operation stopped under brown-out conditions where the voltage value of the input is reduced to a predetermined value. The switching mode power supply apparatus includes a first rectifying and smoothing circuit, an actuating power supply unit having an overvoltage protection circuit, a switching transistor, a switching transformer, a switching transformer, a second rectifying and smoothing circuit, a third rectifying and smoothing circuit, a constant-voltage circuit, a first protection circuit, and a second protection circuit.

Abstract: The protective equipment switch comprises a mechanical switching contact (2) for a conductor (S1-S3), a latchable switch latch (6) for the switching contact (2), an overcurrent sensor (3) associated with the conductor, and an electromechanical undervoltage relay (7) whose exciting voltage is derived from the conductor voltage and which in its excited state latches the switch latch (6). In the case of overcurrent, the overcurrent sensor (3) causes the separation of the undervoltage relay (7) from its exciting voltage which also drops in the case of undervoltage. Thus both in the case of overcurrent and in the case of undervoltage, unlatching of the switch latch (6) is caused by the same component, namely by the undervoltage relay (7). Preferably the overcurrent sensor (3) is formed by the combination of a current transformer signal with an electronic circuit which itself is preferably an integrated circuit.

Abstract: In a device means having connections means for applying a direct voltage (DCV) and having an undervoltage detection circuit (31), a control voltage (CV) having two different direct voltage values (V5, V6) can be applied via the connection elements (2) and the undervoltage detection circuits (3) can generate a detection signal (DS) which alternates between two different voltage values (V1, V2) similarly to the two direct voltage values (V5, V6). A transition detector (58) is part of a processor (16) , The transaction detectr is means are adapted to detect transitions (TR) between the two values (V1, V2) of the detection signal and by which at least one given program sequence can be started in the processor upon the detection of such transitions.

Abstract: An apparatus for supervising input voltages of a multi-rail power supply includes a corresponding voltage detector unit electrically connected to each rail for ascertaining values of the input voltages of each rail. An output of each voltage detector unit is electrically connected at a wired-or node. A pull-up resistor is connected between the wired-or node and a power supply for pulling the voltage level of the wired-or node high. Circuitry generates a power-good signal responsive to the voltage of the wired-or node being greater than a predetermined threshold voltage.

Abstract: The invention relates to a device to neutralize an electronic circuit when it is being powered or disconnected. It can be applied more particularly to electronic circuits powered by low voltages on the order of 1.8 volts. The device of the invention is not significantly affected by variations, due to manufacturing conditions, in the values of its components. The invention may be applied to the field of programmable electrical memories.

Abstract: There is provided a power supply system which is capable of eliminating inconvenience affecting a storage device in the event of a power failure. Monitoring control means monitors supply voltage provided by a DC power supply connected to a power-supplied device and outputs a warning signal to transition means when the absolute value of the supply voltage becomes equal to or smaller than a predetermined voltage value. The transition means causes transition of the operative state of a storage device included in the power-supplied device to an operation terminated state. More specifically, if the storage device is a hard disk drive and the hard disk drive is performing write operation, the hard disk drive is caused to undergo operative state transition to a stable state in which the write operation has been terminated.

Abstract: A motor controller for a battery-powered electric motor automatically disables the motor when the battery voltage (1) remains below a first, higher level for a longer time when the motor is off, or (2) remains below a second, lower level for a longer time when the motor is on, or (3) falls below a low level less than about one quarter the nominal level of the voltage for a shorter time. The motor is automatically enabled when the battery voltage rises to a higher level for a preset time period, indicative of charging of the battery.

Abstract: Device for controlling the stopping of a shrouding product driven by an asynchronous motor having a phase-shifting capacitor (1) stopping the motor when the shrouding product encounters an abutment or an obstacle and utilizing for this purpose at least one operating parameter of the motor so as to detect the appearance of a resisting overtorque. This device furthermore comprises means (4) for detecting a dip in the supply voltage of the local network and means for disabling the control of stoppage when the supply voltage falls below a specified value and for as long as this voltage remains below this specified value.

Abstract: A motor operator with a continuity sensor has a test current injector and a voltage sensor arranged to determine if a loss of AC voltage is due to a discontinuity, such as a blown fuse, in the circuit of a transformer powering the motor operator rather than a loss of voltage from an AC power line. A line voltage detector, such as a resistive or capacitive voltage divider, can also be used with a continuity sensor to distinguish between a discontinuity in the voltage detector and a loss of line voltage. Based on the cause determined by the continuity sensor, signals are generated either to motor operate a disconnect switch or not to.

Abstract: A battery drain limitation circuit for use in engine powered vehicles and equipment which rely upon a battery to start the engine and also to operate accessories. When the engine is not running, the circuit disconnects the battery from all loads when battery charge, as measured by either one of two complementary means responsive to high and low drain rates, respectively, falls to a level below which the battery charge may not be sufficient to start the engine. High drain rates exaggerate battery voltage reduction below no load voltage levels, and are detected by a low cutoff voltage level after which the battery voltage recovers to reflect sufficient charge to start the engine. Battery dissipation from low drain rates is prevented by a long timing delay following detection of a high cutoff voltage level. The circuit is rendered inoperable if the engine is running, by means of a microphone which detects engine noise. The device is simple to install at the battery.

Abstract: A output driving circuit having an output driving element, an overshoot protection mechanism, and an undershoot protection mechanism. When the overshoot protection mechanism senses an overshoot voltage at the output terminal of the output driving element, it raises the voltage at the control terminal of the output driving element. This serves to maintain the voltage between the output terminal and the control terminal of the output driving element within a safe range, thereby preventing overstress or damage to the element. When the undershoot protection mechanism senses an undershoot voltage at the output terminal of the output driving element, it lowers the voltage at the control terminal of the output driving element. This serves to maintain the voltage between the output terminal and the control terminal of the output driving element within a safe range, which in turn prevents overstress and damage to the element.

Abstract: A power source circuit includes switch for connecting and disconnecting a power source to and from a circuit proper; stabilizing means for suppressing a variation of an input voltage to stabilize the input voltage; voltage increasing means for increasing the input voltage in amplitude; switching means for controlling a voltage increasing operation; rectifying means for rectifying a switching waveform; smoothing means for smoothing a rectified waveform; and control means for controlling an output voltage to be constant in amplitude. In the power source circuit, the start of operating the power source circuit is delayed behind the start of supplying electric power. Therefore, it is prevent a power source circuit from failing to operate under the condition that a power source of a large internal resistance is coupled thereto, and the rush current, for example, causes the power source voltage drop.

Abstract: In a power distribution system, a reliable, accurate, and energy efficient fault circuit indicator is provided through a microcomputer-based fault current indicator design. First, reliability is improved inherently because the microcomputer, and the software embedded therein, replace the functionality of numerous discrete, less reliable electronic components found in prior designs. Second, the embedded software is capable of placing the fault current indicator in one of a number of energy conservation states, without compromising the fault current indicator's ability to provide information relating to the occurrence of a fault. Finally, greater fault current indication accuracy is achieved by detecting excessive line current, followed by a significant drop in line voltage.

Abstract: A first MOS transistor (5) is provided between a power source terminal and an input terminal (3). A second MOS transistor (6) is provided between a ground terminal (2) and the input terminal (3). The gate of the first MOS transistor (5) is electrically connected to a node (8) and a resistor (9) is electrically connected between the node (8) and another ground terminal (2). The gate of the second transistor (6) is electrically connected to the ground terminal (2). When negative pulse-shaped static electricity is applied to a circuit constructed as described above, the potential applied to the gate of the first MOS transistor (5) is limited low by a voltage drop developed across the resistor (9). Therefore, the current flowing between the source and drain of the first MOS transistor (5) can be controlled low and a substrate current produced due to impact ionization can be prevented from flowing. It is thus possible to obtain a stabler operation of a semiconductor integrated circuit device.

Abstract: An apparatus and method for extending the supply of reserved power during an interruption to power supplied by a primary power supply in an in-flight entertainment system is disclosed. The apparatus has a power supply that provides a first supply voltage and a capacitor coupled to the power supply that stores a second supply voltage. The apparatus further has a detector circuit that generates a first signal upon detection of an interruption in the first supply voltage. A control circuit coupled to the detector circuit, the capacitor and the power supply, generates a second signal in response to the first signal. A processing circuit coupled to the power supply, the capacitor and the control circuit, disables its operation in response to the second signal. The capacitor provides the second supply voltage to the control circuit in response to the interruption.

Abstract: A snubber device for a power switch comprising a sensing device coupled in the output circuit of the power switch, the sensing device having a reference input and providing an output indicating if a transient pulse of a magnitude greater than a preset range occurs in the output circuit of the power switch. A further electronic switch is provided having an input coupled to an output of the sensing device and coupled across the power switch, the further electronic switch being turned on by the sensing device in the event the sensing device detects a transient pulse beyond the preset range, thereby completing a shunt circuit across the electronic switch and dissipating the transient pulse.

Abstract: An abnormality detection and protection circuit is provided in association with a driving circuit for a semiconductor device, for detecting plural types of abnormalities and protecting the device from the abnormalities. The present circuit includes a plurality of abnormality detecting devices for detecting the plural types of abnormalities, respectively, a plurality of abnormality storage circuits each provided for the corresponding abnormality detecting devices for storing occurrence of the corresponding type of abnormality, and an abnormality transmitting circuit that transmits a signal representing the detected type of the abnormality to an overall control system for controlling a plurality of semiconductor devices.

Abstract: A printed circuit board includes an edge connector operable to be coupled to an expansion bus. An integrated circuit is mounted on the printed circuit board and is coupled to the edge connector. The integrated circuit is operable to snoop memory operations on the expansion bus and cause selected memory data to be stored in a memory on the printed circuit board. A first power conductor extends across a first portion of the printed circuit board and is coupled to the integrated circuit. A second power conductor extends across a second portion of the printed circuit board and is also coupled to the integrated circuit. The circuit board also includes a decoupling unit connected between the first power conductor and the second power conductor. The decoupling unit causes disconnect of the first power conductor from the second power conductor during times in which voltage within the first power conductor is less than voltage within the second power conductor.

Abstract: An electronic device (102) includes a power supply (114), an amplifier circuit (132), and a power down protection circuit (160). The power supply (114) supplies power to the electronic device (102). The amplifier circuit (132) is powered by the power supply (114) to amplify a signal into an amplified output signal and controllable to vary a power level of the amplified output signal. The power down protection circuit (160) is coupled directly to the power supply (114) to lower the power level of the amplified output signal of the amplifier circuit (132) when the power supply (114) falls below a threshold.

Abstract: A method and control circuit for an electronic switch, and more particularly the high side switch in a bridge circuit. Control is established by continuous and/or the combination of continuous and pulsed signals. Fail safe undervoltage protection is provided for the high side switch based on the adequacy of both high side and low side control voltages.

Abstract: A module for use with the circuit breaker, the module being arranged to be mounted on an end of the circuit breaker and to monitor and/or control the circuit breaker and/or an electrical circuit control thereby in use. The module can be active or passive, and, where circuit breakers are ganged in side-by-side relationship, the module can be equal in width to the width of the gang breaker unit to which the module is mounted. The invention also resides in the combination of a module and a circuit breaker.

Abstract: A storage capacitor of a hold-up circuit is connected by a resistor to the urrent conducting bus supplying operating voltage to computer hardware from a power source. The capacitor is thereby charged to the operating voltage level in order to subsequently maintain computer operation by discharge through a diode during power interruption of a relatively long duration determined by the capacitor charge and a predetermined drop in voltage applied to the computer load causing its shutdown. Detection of such drop in voltage is operative through an opto-isolator to safely discharge the capacitor by relay controlled grounding thereof.

Abstract: A transient suppression circuit suppresses transients on a dc power bus, extending between a power supply and a load which carries a first voltage having a nominal value, by charging a capacitor to a second voltage greater than the nominal voltage, detecting a threshold at which the first voltage drops below its nominal value by more than a first predetermined amount and coupling energy from the capacitor to the bus to compensate for the drop in voltage in response to detecting the threshold.

Abstract: Disclosed is a portable information processing apparatus that can detect a remaining battery charge level quickly and comparatively accurately while it eliminates the influence of noise that can be caused when a remaining battery charge is to be detected, that can prevent a battery pack from being mistakenly identified as abnormal by delaying the timing for detecting the unbalanced state of the voltages at each voltage row, which can occur temporarily during the charging of a secondary battery pack when a plurality of cells are connected in series and parallel, that changes power control procedures for each different suspend mode so that it can control with no problem the supply of power to a unit, such as a printer unit, that consumes a large current, even when a remaining battery charge is comparatively low and that can match the phases of the individual units to ensure rebooting is actually performed when a power supply SW is turned on or off at an arbitrary time.

Abstract: A sleep switch connected to a ramp pin, an undervoltage lockout circuit and a hysteretic differential comparator for use in the undervoltage lockout circuit are disclosed. An integrated circuit has a comparator that receives a voltage from the ramp pin which it compares with a control voltage. The sleep switch connected to the ramp pin is activated when the ramp pin is below a predetermined voltage threshold at which point it puts the integrated circuit into a low power consumption sleep mode. The undervoltage lockout circuit includes a detection leg connected between the supply terminal and ground. A current supply is enabled when the voltage across a resistive portion of a detection leg rises above a first threshold. A differential comparator is responsive to the detection voltage for enabling the current supply. The differential comparator may include three transistors arranged to provide first and second detection thresholds so as to establish a hysteresis.

Abstract: A communication system is presented whereby sequences of video screens sent from a host CPU to a video controller can be stored and subsequently retrieved by a terminal located remote from the host CPU. Detection logic, controller memory, processor and a communication unit are compiled as a system configured upon a PCB. The PCB is configured to maintain certain vital functions even if power supplied from an expansion bus ceases. The PCB may employ a battery which maintains processor and controller memory activities and communication therebetween for a period of time sufficient to sustain video screen information stored within the controller memory. Thus, decoupling circuitry is present which prevents drain upon the battery if the communication unit is not being used. The decoupling unit separates power and signal conductors between portions of the printed circuit board.