Abstract: A circuit for providing regulated power to a microelectronic device is disclosed. The circuit includes an error amplifier, a transistor, and a supplemental voltage supply coupled to the transistor. The supplemental voltage supply supplies requisite bias to operate the transistor near its saturation point.

Abstract: A rail tracking system and method for providing precise tracking of voltage levels to a dual supply voltage Integrated Circuit. A switch mode DC-DC voltage regulator is used to derive the lower of the two voltage levels from the higher level. The switch mode regulator employs a pulse width modulator (PWM) to derive the lower voltage level. A separate supply source is utilized to power the PWM and the timing of the supply voltage is such that the PWM has reached steady state before the higher voltage level is provided to the regulator.

Abstract: In the regulated power supply circuit, an overcurrent detection circuit detects the flow of an overcurrent through a transistor acting as an output control element and supplies a result of the detection to a cut-off operation prohibition circuit. During non-startup time of the regulated power supply circuit, the cut-off operation prohibition circuit simply relays a result of the overcurrent detection circuit detecting an overcurrent to a cut-off circuit without introducing any changes to the result. The cut-off circuit increases a base potential of the transistor according to the result of the detection of an overcurrent to cut off the output of the transistor. It is ensured that the output voltage rises even if the overcurrent detection circuit has activated the cut-off circuit upon detection of the overcurrent temporarily passing through the transistor during a startup.

Abstract: In a reference voltage circuit 2 and an error amplifier 3 in a voltage regulator, a power supply is taken from an input voltage Vdd when an output voltage Vout is lower than an arbitrary set output voltage Vo and from the output voltage Vout when the output voltage Vout is higher than an arbitrary set output voltage Vo, to thereby largely suppress a noise contained in the input voltage from reflecting the output voltage Vref of the reference voltage circuit, etc.

Abstract: A device for detecting the application of a high voltage signal to an internal node of an integrated circuit includes a high-voltage divider circuit and a threshold detection circuit. The threshold detection circuit receives a signal given by the output of the divider circuit, and provides a threshold crossing detection signal at an output thereof based upon the signal crossing a threshold. The detection circuit is connected between the logic supply voltage and ground, and further includes a negative feedback loop. The negative feedback loop is connected to the output of the divider circuit to limit the voltage build-up of the high voltage signal at the output thereof after the crossing of the detection threshold by the signal.

Abstract: A voltage regulator with a current limiter includes a voltage regulating circuit including an amplifier circuit and a feedback circuit. The amplifier circuit includes a ballast or pass resistor and the feedback circuit supplies a first feedback voltage to the amplifier circuit, which is compared to a reference voltage. The voltage regulator further includes a current limiter circuit including a current limiter transistor in series with the ballast transistor and an output of the voltage regulator and a feedback circuit supplying a second feedback voltage to a controller for controlling the current limiter transistor. The controller causes the current limiter transistor to operate between saturation and blocking conditions depending on whether the second feedback voltage, which is representative of the output of the voltage regulator, is above or below a predetermined threshold voltage.

Abstract: During transient operation of a voltage regulator, the gate of p-channel MOS pass transistor may be pulled down during the transient period to cause excessive surge current. The surge current is limited by using the pass transistor as a current mirror during the transient period. After the transient period, the pass transistor resumes its role as an element together with a differential amplifier and a reference voltage in a feedback loop to regulate the output voltage.

Abstract: A step-down switched-mode power supply circuit includes a transformer having at least one primary winding and at least one secondary winding, a current sensing device for sensing a current through a primary winding of the transformer, a first switch and a second switch, a first comparator for determining if the current through the current sensing device exceeds a threshold, a voltage regulator coupled to the secondary winding to produce a regulated voltage, a second comparator for determining if the regulated voltage has drooped below an acceptable level, a counter coupled to the second comparator for generating a signal having a fixed number of switch cycles, and control circuitry for generating signals controlling the first switch and the second switch and responsive to the first comparator to enter a power saving mode disabling the signals, and to the second comparator to temporarily exit the power saving mode for a fixed number of cycles when the regulated voltage has drooped below an acceptable level.

Abstract: A first constant voltage circuit includes an operational amplifier having a reference voltage applied to a first input terminal thereof and a voltage obtained as a result of an output voltage being divided applied to a second input terminal thereof, and controls an output transistor with an output of its operatioanal amplifier. A second constant voltage circuit includes an operational amplifier having a reference voltage applied to a first input terminal thereof and a voltage obtained as a result of the output voltage being divided applied to a second input terminal thereof, and controls the output transistor with an output of its operatioanal amplifier, a current consumption of the second constant voltage circuit being smaller than a current consumption of the first constant voltage circuit. A switching part is provided for each of those operational amplifiers and makes connection and disconnection between an output terminal of the operational amplifiers and the output transistor.

Abstract: A voltage regulation device is provided for receiving a voltage at an input node and supplying a regulated voltage to electronic circuitry at an output node. The device includes a switching circuit that is coupled between the input node and the output node, and a control circuit that is coupled to the switching circuit. When the voltage level at the output node is below a threshold voltage, the control circuit controls the switching circuit so as to substantially short-circuit the input node and the output node. On the other hand, when the voltage level at the output node is not below the threshold voltage, the control circuit controls the switching circuit so as to substantially isolate the input node from the output node. In a preferred embodiment, the switching circuit includes an NMOS transistor, and the control circuit includes a differential amplifier that supplies a control signal to the gate of the NMOS transistor. A smart card containing a voltage regulation device is also provided.

Abstract: A semiconductor integrated circuit includes a booster for boosting a power supply voltage, and outputting the boosted voltage; an output circuit being supplied with the boosted voltage, and generating an output voltage from the boosted voltage; a reference voltage generator being supplied with the power supply voltage, and generating a reference voltage from the power supply voltage; a voltage divider being supplied with the output voltage from the output circuit, and dividing the output voltage with a predetermined voltage ratio; and a differential amplifier being supplied with the reference voltage and the divided voltage, and controlling the output circuit by supplying the output circuit with a voltage obtained by performing differential amplification on the reference voltage and the divided voltage according to the power supply voltage, thereby maintaining the output voltage from the output circuit at a predetermined voltage.

Abstract: A low drop out voltage regulator includes an error amplifier (12) having a first input coupled to a first reference voltage (VREF), a second input receiving a feedback signal, and an output (15) producing an output signal (VAMPOUT). An output transistor (18) has a gate, a drain coupled to an unregulated input voltage (VIN), and a source coupled to produce a regulated output voltage (VOUT) on an output conductor (19). A feedback circuit (20,22) is coupled between the output conductor (19) and a reference voltage (GND) to produce the feedback signal. A capacitor (16) is coupled between the output (15) of the error amplifier and the gate (17) of the output transistor (18). A servo amplifier (24) has a first input coupled to a second reference voltage (VVREF), a second input coupled to the output (15) of the error amplifier. A low current charge pump circuit (26B) supplies an output current into a supply voltage terminal of the servo amplifier.

Abstract: A voltage regulator circuit (1) able to detect a latch-up phenomenon disturbing the voltage to be regulated, to suppress such phenomenon and re-establish the voltage at a predetermined level. The circuit a bipolar transistor (2), a resistor (5) and substantially constant voltage supply means (6). The circuit (1) also includes voltage detection means (11) arranged to receive the regulated voltage (Vreg), and to supply a control voltage to said transistor (2) which can control the switching thereof between a conducting state and a blocked state, so that the transistor (2) is in the blocked state when latch-up causes the regulated voltage to drop below a first voltage level, and so that the transistor (2) is in the conducting state when the regulated voltage is lower than a second voltage level, the latch-up being suppressed below such level.

Abstract: An apparatus for driving an electric load includes a switch device interposed in a current feed path from a direct-current power source to the electric load. A sensing resistor connected in series with the switch device operates for detecting a load current as a voltage value. The load current flows into the electric load via the switch device. A signal generation device operates for generating a trapezoidal wave signal in response to externally applied commands to turn on and turn off the electric load. The trapezoidal wave signal gradually varies from a first predetermined voltage to a second predetermined voltage when the electric load starts to be turned on. The trapezoidal wave signal gradually varies from the second predetermined voltage to the first predetermined voltage when the electric load starts to be turned off.

Abstract: A control circuit (1) for controlling a FET (2) for outputting a 3.3 volt or a regulated 1.5 volt output to an AGP bus on a PC motherboard in response to a TYPEDET signal being applied to a control terminal (3) of the control circuit (1) through an input (6) of a voltage divider circuit (8). The TYPEDET signal is received from a video card receiving slot and indicates the type of video card in the slot of the motherboard. An amplifier (20) outputs a control signal to the gate of the FET (2) for either disabling the FET (2), or enabling the FET (2) to output the 1.5 volt or the 3.3 volt outputs. A decoding circuit (30) decodes the state of the control terminal (3) and controls the amplifier (20) to disable the FET (2) during power up. When the TYPEDET signal of zero volts, the FET (2) is operated to output the 1.5 regulated voltage output. When the TYPEDET signal is floating, the FET (2) outputs the 3.3 source voltage.

Abstract: A frequency sensing NMOS voltage regulator is disclosed. A NMOS source follower transistor has a gate connected to a predetermined gate voltage, a drain coupled to an external supply voltage through a PMOS switching transistor, and a source connected to a load. The gate of the PMOS transistor is controlled by a delay circuit through which a pulse derived from the system clock is passed. Through the use of the delay circuit and the PMOS transistor, the amount of current produced by the NMOS transistor is made a function of the cycle rate of the system clock and the current provided by the NMOS transistor tracks the frequency-dependent current requirements of the load, resulting in a reduced variance of the supply voltage Vcc over a wide current range.

Abstract: Provided is a linear voltage regulator and method of use thereof which controls the voltage input to an integrated circuit such as a digital signal processor (DSP) or a processor. The method includes the sequential steps of generating a first ramping voltage to a load connection when the load is in a start-up phase, and generating a second operating voltage to the load connection when the load is in an operational phase. The linear voltage regulator includes a control circuit and a regulation circuit that implements the method.

Abstract: A rail tracking system and method for providing precise tracking of voltage levels to a dual supply voltage Integrated Circuit. A switch mode DC—DC voltage regulator is used to derive the lower of the two voltage levels from the higher level. The switch mode regulator employs a pulse width modulator (PWM) to derive the lower voltage level. A separate supply source is utilized to power the PWM and the timing of the supply voltage is such that the PWM has reached steady state before the higher voltage level is provided to the regulator.

Abstract: A power circuit including means for preventing the generation of an inrush current during the power circuit's initial operation without increasing the size of the power circuit is described. The power circuit comprises an output transistor for supplying a current from a power supply to an output terminal, and a differential amplifier for controlling the current supplied by the output transistor in such a manner as to regulate a voltage at the output terminal based on a preset reference voltage. A limiting transistor is provided as a source follower on a current path at the output stage of the differential amplifier. The gate potential of the output transistor is controlled using the source potential of the limiting transistor. Before the power circuit starts to operate, an operation controller charges a capacitor to control the gate potential of the limiting transistor so that during the initial operation of the power circuit, the capacitor is discharged by using a current source.

Abstract: A power-generation detection circuit for detecting a power-generation state by an AC voltage supplied from a power-generation device including a capacitor, and switching element, a resistor, and an inverter circuit which controls the charging of the capacitor by a power-generation device. The switching element is switched by the AC voltage from the power-generation device. The voltage of the capacitor is detected by the inverter circuit thereby performing power-generation detection.

Abstract: The present invention relates to a system for providing a regulated voltage meant to supply a load, including a source for providing a substantially constant current approximately corresponding to the maximum current likely to be surged by the load, and a device receiving the constant current and regulating the load supply voltage, at least one capacitor being connected between an output terminal of the regulation device and the ground.

Abstract: An adjustable power control module includes a supply voltage comparison circuit, a signal dependent current source, and a power regulation module. The supply voltage comparison circuit is operably coupled to compare a supply voltage with a low-powered threshold. When the supply voltage is less than the low-power threshold, the supply voltage comparison circuit provides a corresponding indication to the signal dependent current source. The signal dependent current source generates a first regulated current when the supply voltage is less than the low powered threshold based on the indication and generates a second regulated current when the supply voltage is above the low power threshold. The second regulated current is larger than the first regulated current. The power regulation module provides the first or second regulated current to an associated circuit. As such, the current supplied to the circuit is regulated based on operating conditions for the circuit.

Abstract: A multi-output converter having a transformer with several windings, a first winding being connected to a first switching element the duty cycle of which is controlled by a control circuit. A second winding is connected to a rectifying means and to a first filtering means, including a first inductance, in order to produce a first regulated output voltage. A second output voltage, corresponding to an auxiliary output, is generated and regulated by a fourth switching element connected to a second filtering means, including a second inductance magnetically coupled to the first inductance. A control circuit controls the switching of the fourth switching element by means of a control signal obtained from a voltage present on the second winding.

Abstract: A power source circuit for a flash memory includes a positive circuit section for generating a positive voltage source, a source follower transistor for converting the impedance of the first voltage source, a negative circuit section for generating a negative voltage source while maintaining a voltage difference between the output of the source follower transistor and the negative voltage source at a first reference potential. The positive circuit section includes a voltage compensating transistor having a threshold voltage equal to the threshold of the source follower transistor.

Abstract: A step-down switched-mode power supply circuit includes a transformer having at least one primary winding and at least one secondary winding, a current sensing device for sensing a current through a primary winding of the transformer, a first switch and a second switch, a first comparator for determining if the current through the current sensing device exceeds a threshold, a voltage regulator coupled to the secondary winding to produce a regulated voltage, a second comparator for determining if the regulated voltage has drooped below an acceptable level, a counter coupled to the second comparator for generating a signal having a fixed number of switch cycles, and control circuitry for generating signals controlling the first switch and the second switch and responsive to the first comparator to enter a power saving mode disabling the signals, and to the second comparator to temporarily exit the power saving mode for a fixed number of cycles when the regulated voltage has drooped below an acceptable level.

Abstract: The present invention includes a circuit for detecting voltage levels in an integrated circuit including a first reference voltage(324), a first differential amplifier(349) having an inverting input terminal connected to the first reference voltage, a non-inverting input terminal and an output terminal, a first transistor (356) having a control terminal connected to the output terminal of the first differential amplifier, having a first current handling terminal connected to a voltage supply terminal and having a second current handling terminal connected to the non-inverting input terminal of the first differential amplifier, a first load (358) device having a first terminal connected to the second current handling terminal of the first transistor and a second terminal, a second load device (360) having a first terminal connected to the second of the first load device and a second terminal connected to a second reference potential, a second differential amplifier (391) having an inverting input terminal, a n

Abstract: A voltage regulator which has two regulation circuits and a comparator for controlling the two regulation circuits is disclosed. The input of the comparator is connected to a power supply voltage such that the output of the comparator changes states when the power supply voltage reaches a predetermined voltage of around 8 volts. The first regulation circuit is enabled to provide the Vcc from the battery voltage until the power supply voltage reaches around 8 volts which is when the comparator changes states. At that point, the first regulation is disabled and the second regulation circuit is enabled to provide the Vcc voltage from the power supply voltage. Since the power supply voltage never reaches the load dump high voltages, the second pass transistors never gets exposed to a high voltage condition. Also, the first transistor can withstand higher voltages since its base is grounded.

Abstract: A voltage drop compensating circuit is disclosed which compensates for unwanted voltage drops along a DC current conductor connected to an integrated circuit. The compensating circuit includes a differential amplifier connected between a voltage supply and the conductor form the integrated circuit which is marred by the voltage drop. One input terminal of the amplifier is connected to the supply lead and an output terminal of the amplifier is connected to the conductor. A feedback network is connected between another input terminal of the amplifier and the integrated circuit. A potential difference between the two input terminals on the amplifier will lead to the amplifier adjusting a potential on the output terminal until the unwanted voltage drop along the conductor is compensated for.

Abstract: Disclosed is a secure data system power supply having an input coupleable to an input voltage line and an output coupleable to a secure data system and providing isolation between the input voltage line and the secure data system such that information communicated within the secure data system is undetectable from the input voltage line. The power supply does not utilize a linear current source for isolation, and thereby greatly reduces power loss. A constant power flyback converter is adapted to be coupled between the input voltage line and the secure data system. The constant power flyback converter takes as an input from the input voltage line a constant power input and provides at a converter output an output signal for use in powering the secure data system. A shunt voltage regulator is coupled to the converter output and maintains the output signal at a substantially constant voltage.

Abstract: A power sensor circuit including an input terminal, a switch, a nonlinear voltage drop element, and a switching unit, wherein the switching unit provides an output voltage. In response to a voltage difference between a first reference voltage and a second reference voltage, the power sensor circuit outputs a voltage that varies between two states. In one embodiment, the first state is substantially equal to the second reference voltage and the second state is substantially equal to ground. In another embodiment, the power sensor circuit is composed of four metal oxide semiconductor field effect transistors (MOSFETs) that compare a first reference voltage with a second reference voltage and determine whether the second reference voltage exceeds the first reference voltage by a predetermined voltage. If so, then the second reference voltage is produced at the output terminal of the power sensor circuit.

Abstract: A voltage regulator is disclosed which is connected to an external resistor. The voltage regulator provides a regulated voltage and includes first and second transistors. The first transistor has a power terminal connected to a power supply and the second transistor has an output terminal to output the regulated voltage. The second transistor is connected to the first transistor through a common terminal. The external resistive circuit is connected between the common terminal and the output terminal. An output current of the voltage regulator on the output terminal is equal to a sum of a first current passing through the resistive circuit and a second current passing through the second transistor. A control circuit is also provided which is connected to the input of the second transistor to turn on the second transistor for providing the second current when the first current exceeds a predetermined value.

Abstract: A regulator includes a driver stage having an output port for providing an output voltage, a predriver coupled to the driver to control the output voltage provided by the driver stage, a comparator to compare the driver output voltage to a reference voltage, and a feedback element coupled between the driver output port and the comparator. The driver may include a high side transistor having a collector coupled to a collector of a low side transistor, and a current sensing transistor having a base coupled to a base of the low side transistor.

Abstract: A foldback circuit which responds to a voltage differential between the input and output terminals of a voltage regulator in excess of a foldback threshold by lowering the current limit threshold of a current limit circuit. The foldback circuit includes a transistor with a base coupled to the input voltage and an emitter coupled to the output voltage. The collector when conducting provides a current that decreases the current limit threshold. Diodes in the path between the input and output voltages through the transistor may be used in establishing the foldback threshold.

Abstract: An OFF-state voltage generating circuit regulates an OFF-state voltage level, for thin film transistors (TFT) in a liquid crystal display (LCD). A voltage generator receives a common voltage signal and an inverted common voltage signal and generates an OFF-state voltage to turn off the TFT of an LCD. A voltage regulator adjusts the level of the voltage from the voltage generator by varying the resistance of a variable resistor. A timing circuit keeps the voltage regulator from operating for a time during the initial ON-state of the power supply.

Abstract: Two parallel regulator stages, each comprising a transistor (T1, T2, respectively), are provided. The transistor (T2) forms part of the indirect parallel regulator stage and acts directly on the rectifier. It is capable of taking up comparatively large currents and hence is comparatively slow. The transistor (T1) forms part of the direct regulator stage and operates in parallel with the sustaining capacitor. Because of the coarse control provided by the transistor (T2), it need take up small currents only and can hence have a very fast control behavior. Because of the coarse control by the transistor (T2), the alternating voltage on the antenna terminals (LA and LB) quickly breaks down when the RF signal is interrupted; consequently, the transmission rate can be increased in the case of pause interval modulation. Static discharges are also dissipated by the transistor (T2), so that no additional protective circuitry is required for this purpose.

Abstract: In a satellite experiencing alternate periods of light and eclipse, an electrical power control system utilizing direct energy transfer battery charging in a fully regulated electrical bus system to provide and control the system power over both the charging and the discharging cycles of the satellite electrical system.

Abstract: A voltage regulator with load pole stabilization is disclosed. The voltage regulator consists of an error amplifier, an integrator which includes a switched capacitor, a pass transistor, and a feedback circuit. In one embodiment, the integrator circuit includes an amplifier, a capacitor, and a switched capacitor which is driven by a voltage controlled oscillator. The voltage controlled oscillator changes its frequency of oscillation proportional to the output current. In another embodiment, the switched capacitor is driven by a current controlled oscillator whose frequency of oscillation is also proportional to the output current of the voltage regulator. When the output current demand is large, the controlled oscillators increase the frequency which decreases the effective resistance of the switched capacitor thereby changing the frequency of the zero to respond to the change in the load pole.

Abstract: A circuit regulates a voltage by controlling a voltage generator. A voltage divider is coupled between the regulated voltage and a supply voltage, and generates a sense voltage. A clamp circuit is coupled to the divider, and reduces the sensitivity between the supply voltage and the regulated voltage by substantially prohibiting the voltage across itself from exceeding a predetermined value A detector circuit is coupled between the divider and the voltage generator, and provides a control signal that deactivates the generator when the sense voltage reaches a first predetermined threshold, and activates the generator when the sense voltage reaches a second predetermined threshold.

Abstract: An electrical power supply is provided with a regulation stage which on being supplied at its input with a dc input voltage with a significant ripple component (V.sub.S1.sbsb.--.sub.OUT), outputs a dc output voltage (V.sub.S2.sbsb.--.sub.OUT) at a level substantially equal to the dc input voltage value at the troughs of the input ripple component (V.sub.T). As a result of this operation, the power dissipated in the stage is minimized. In order to regulate the dc output voltage (V.sub.S2.sbsb.--.sub.OUT) to be at a particular level, this output voltage is compared to a reference to produce a control signal (S) that is fed back to an upstream regulation stage. This upstream stage then serves to vary the level of the trough voltage at the input of the downstream regulation stage.

Abstract: A DC clamping circuit acting on an input signal to clamp the input signal to a voltage reference is disclosed. The DC clamping circuit comprises a comparator providing an output that decreases whenever the input signal is less than the output. A capacitor is connected to the output of the comparator for absorbing the charge output by the comparator. Finally, a differential amplifier is provided for subtracting the output of the comparator from the input signal and for adding the voltage reference.

Abstract: A voltage regulator with a current limit circuit for limiting pass current in a pass transistor below a current limit threshold and a foldback circuit for lowering the current limit threshold when the voltage differential between the input and output terminals of the voltage regulator exceeds a foldback threshold, where the current limit threshold has a negative temperature coefficient, the current limit circuit comprising two transistors coupled to a sense resistor such that the difference in emitter-to-base voltages of the transistors is equal to the voltage drop of the sense resistor, where the collectors of the two transistors provides first and second currents to first and second resistors, respectively, where the first current is responsive to a pass current flowing through the sense resistor and decreases when the pass current increases, where the second current is independent of the pass current, and the foldback circuit provides a third current to the second resistor when the voltage differential bet

Abstract: A power supply circuit has a switching transistor and a inductance coil that are connected between an input terminal and an output terminal. A voltage across a capacitor that is connected between the output terminal and a ground potential node is extracted as an output voltage. Between the output terminal and the ground potential node, a Zener diode and a resistor are connected in series. When a voltage across the resistor exceeds a predetermined value, the switching transistor is put into a cut-off state by a drive circuit.

Abstract: A power supply damping circuit (22) coupled across the leads of a power supply (20) is able to substantially damp or reduce the resonant response of the power supply and any associated noise, ringing, or oscillation produced by the power supply. The power supply damping circuit (22) provides a low value real impedance in parallel with the power supply (20) as a means of damping the power supply resonance circuit. The power supply damping circuit (22) includes a transconductance element (36) capacitively coupled across a power supply (20). A bias control (54) provides a bias current to the transconductance element (36) to set the static current of the transconductance element (36).

Abstract: A primary regulator having a zero-crossing detector and a voltage reference coupled to a processor is provided. The processor controls the on time of a primary transformer via a switching device isolated from the processor via a coupler A method of regulating a power supply to maintain a desired output voltage at a load including the steps of measuring an average output voltage at a load and controlling the on time of a switching device serially connected to a primary transformer input based on the measured output voltage and a zero-crossing signal.

Abstract: Internal supply voltage generating circuits generate internal supply voltages at voltage levels below an external supply voltage. The internal supply voltages operate peripheral circuits and array circuits. A reference voltage generates a constant reference voltage. First and second dividing circuits output a given voltage in response to the internal supply voltage. First and second differential amplifiers compare the reference voltage with each of the output voltages from the first and second dividing circuits. First and second driving circuits supply the internal supply voltage from the external supply voltage. First and second voltage boosting circuits clamp output voltage levels for the first and second driving circuits from the external supply voltage and raise the clamped output voltage level of the first driving circuit higher than the clamped output voltage level of the second driving circuit.

Abstract: A method for reducing the transient response time of a voltage regulator when the load attached to it is entering or exiting a lower power consumption level by changing the bandwidth of the voltage regulator without compromising its stability, and a bandwidth regulator for implementing such a method are disclosed, wherein the bandwidth of the voltage regulator is changed based on a signal sent by a control device when it senses that the component is about to change power consumption levels.

Abstract: An AC-to-DC converter and regulator normally receives power from an AC utility line and provides a stable DC output to a load, such as the power amplifier and transmitter of a cell site. The DC output, or a separate dedicated output from the converter, is used to charge a backup battery when AC power is available. If AC power is interrupted, the backup battery provides power to the load by way of a separate DC-to-DC differential converter. The battery is connected in parallel with the differential converter input, but in series with the differential converter output. Thus, the differential converter receives operating power from the battery, and outputs a voltage which is summed with the battery output to drive the load. A control circuit for the differential converter senses the voltage provided to the load, and supplies a signal to the differential converter to adjust its output as necessary to maintain the optimum aggregate output to the load.

Abstract: A control circuit for, and method of, alternately controlling one of at least two controllable characteristics of a controlled circuit.

Abstract: An AC-DC adapter includes a power transformer to which an AC voltage is applied, a rectifier circuit for rectifying and smoothing an AC voltage developed across the secondary side of said power transformer, and DC voltage stabilizing member for stabilizing a DC voltage outputted by said the rectifier circuit.

Abstract: The present invention relates to an apparatus and method for voltage regulation. The apparatus includes an error amplifier circuit in communication with an external reference voltage input. The error amplifier circuit produces an error voltage that is proportional to the difference between an external reference input voltage and an output voltage. A series pass circuit is in communication with the error amplifier circuit and is responsive to the error voltage. The method comprises the steps of comparing an external reference voltage to an output voltage, generating an error voltage proportional to the difference between the external reference voltage and the output voltage, and regulating the output voltage based upon the error voltage.