Abstract: There are provided a first constant-current circuit and a second constant-current circuit, and a first resistor connected in series with the first constant-current circuit generates a band-gap voltage. The first constant-current circuit and the second constant-current circuit constitute a current Miller circuit, and a part of a current that flows through the second resistor connected in series with the second constant-current circuit is outputted as a constant current source. The constant-current power supply IC, which has the above-mentioned arrangement, is designed as follows: the first resistor and the second resistor have a predetermined line-width ratio that is determined in such a manner that if the respective line-widths vary by virtually the same value, a varied amount in the second constant current value that has been caused by a variation in the value of resistivity of the first resistor is cancelled by a varied amount caused by a variation in the value of resistivity of the second resistor.
Abstract: A method for regulating the power in a load connected to the mains through a controlled switch and a device for implementing the method. The method includes the following steps: detecting a mains synchronization pulse, which determines the start of a cycle, within a fixed time interval of the preceding cycle; as soon as the pulse has been detected, waiting for the end of the fixed interval, then counting down a first time interval that substantially corresponds to a selected time interval; at the end of the first time interval, triggering the switch on and counting down a second time interval that ends before the normal arrival of the next synchronization pulse; and at the end of the second time interval, counting down the fixed time interval within which the next synchronization pulse must be detected.
Abstract: In an integrated microcircuit device the supply voltage is monitored by a pair of threshold detector logic circuits configured to generate a first control signal when said supply voltage crosses over a minimum level, and a second control signal when said supply voltage crosses over a maximum level. The control signals are used to configure the device into distinct modes of operation, whereby the functions of the device and the voltage level of the power supply applied to them during testing or operation may be controlled by varying the supply voltage.
Abstract: A high power factor regulator circuit which includes a variable multiplier, permitting the high power factor regulator circuit to be used with a number of input line voltage levels. In one embodiment a comparator determines the multiplication or gain factor to be applied in a control loop by comparing the rectified AC input voltage to a predetermined threshold value.
Abstract: A ground power unit capable of no-break power transfer includes a rectifier for converting power from commercial mains to direct current, a switching circuit, a power transformer, and a pattern generator for controlling the operation of the switching circuit. Voltage and current sensors monitor whether the phase of the ground power unit is leading or lagging the phase of the aircraft power bus at the tinge of power transfer. The frequency and phase of the pattern generator converter is adjusted to bring the two systems into alignment quickly, well before the power transfer operation is completed. The ground power unit limits the power transfer between the two systems to prevent the overloading of either.
March 11, 1993
Date of Patent:
October 11, 1994
Hobart Brothers Company
Stephen H. Elliott, Theodore J. Fahrer, Allen D. Kelly, Larry E. Heisey
Abstract: A current switch (30) includes a switching transistor (Q1) having a collector electrode for coupling to a first voltage source (Vcc), an emitter electrode, and a base electrode for receiving a control signal (V.sub.IN1). Switching transistor (Q1) is responsive to the control signal (V.sub.IN1) to turn on to produce a collector current (I.sub.CQ1). A bias circuit (26) is coupled to the emitter electrode of the switching transistor (Q1) for causing the collector current (I.sub.CQ1) of the switching transistor (Q1) to have a predetermined value. The bias circuit includes first and second transistors (Q3 and Q4) having base electrodes coupled in common. The first transistor (Q3) has a collector electrode coupled to the emitter electrode of the switching transistor (Q1) and an emitter electrode for coupling to a second voltage source (Vss). The second transistor has a collector electrode for coupling to a current source (24) and an emitter electrode for coupling to the second voltage source (Vss).
Abstract: An inexpensive output circuit of a PWM inverter for PWM controlling a coil voltage of a motor with small control error of voltage at a motor winding terminal and low power consumption includes an N channel power MOS-FET, a P channel power MOS-FET, a current control circuit 1 having a current output terminal, and a current control circuit 2 having a current input terminal. A current flowing out from the current output terminal of the current control circuit 1 and a current flowing in from the current input terminal of the current control circuit 2 are subjected to particular control to thereby control the N channel power MOS-FET and the P channel power MOS-FET.
October 29, 1993
Date of Patent:
September 13, 1994
Matsushita Electric Industrial Co., Ltd.
Abstract: A switching power supply that converts an input AC or DC voltage to a regulated output DC voltage while offering electrical isolation between the input and output stages through use of solid state switches and charge storage devices in place of isolation transformer used in traditional systems. The power supply uses two series connected switching blocks that alternately charge and discharge a storage capacitor, wherein each switching block includes a pair of switches which may be turned on and off with a duty cycle adjusted by a controller. The duty cycle and on time of each block is adjusted such that respective blocks are never turned on at the same time, thereby providing electrical isolation.
Abstract: The invention is directed to an arrangement for the current-regulated control of several actuators by a control computer. An individual control transistor is provided for each actuator. A single measuring resistor in series with a further control transistor defines a measuring and control arrangement for all actuators. Each individual control transistor for the respective individual actuators is connected in series with respective resistors. The resistance value of each of the resistors corresponds to the resistance value of the measuring resistor. Furthermore, switching elements are provided and controlled by the control computer. The actuators are connected in series with the measuring and control arrangement for a pregiven measuring and control time by the switchover elements. The actuators are normally in series with the individual control transistors assigned thereto.
Abstract: A magnetic circuit with several magnetic components integrated on one or more common magnet cores is utilized in a current supply circuit known per se. The circuit comprises a transformer, the secondary winding ends of which are connected to uniform electrodes of a pair of rectifier diodes, the second electrodes of which are connected to one output terminal of the power supply circuit. Additionally, it includes two reactive components, and the first electrodes of the diodes are connected to the second output terminal of the power supply circuit via one of the reactive components. The number of turns of the two reactive components is essentially chosen to equal the number of secondary turns on the transformer. The two reactive components are positioned on each separate core part so that the resulting magnetic flux in common core parts substantially equals the difference between the magnetic flux of the two core parts, and the secondary winding of the transformer is positioned on the common core parts.
Abstract: A circuit array, adapted to be coupled to a load and a source of a main AC voltage, for reverse phase angle control whereby a current flow in the load is limited to a defined phase angle (.alpha.) of the main AC voltage, comprising the following components for sequential control of the reverse phase angle control: a switching element, connected to the load and coupled to the source of the main AC voltage, for actuating the current flow in the load; a time determining component; and an integrated circuit.
Abstract: A non-contact type load-dispatching equipment having a power supply side core and a receiving side core both provided with a plurality of teeth wound by winding, each of teeth top surfaces formed by respective teeth is oppositely positioned to each other via a gap being magnetically connected for supplying power without contact at the time of power supply, whereinteeth top surfaces of respective teeth of the power supply side core and receiving side core are disposed oppositely on the respective circumferences with a gap therebetween which allows coupling-uncoupling of the cores therethrough;light signal generating circuit for generating light signals which indicate receiving side voltages is provided in the power receiving side;voltage signal generation circuit which generates corresponding voltage signals on receiving the light signals and cut-off circuit for cutting off power supply when the generated voltage signal is lower than the predetermined value, where the voltage signal generation and cut-off circ
Abstract: A remote power controller module for use in power distribution systems having a number of current limiting channels that are capable of being paralleled to provide current pathways from a power source to a load. In one embodiment, the current limiting channels may contain control and monitoring circuitry for monitoring the trip status of all channels and for disabling all paralleled channels in response to the disablement of one channel. The control and monitoring circuitry may also reset the disabled current limiting channels. In another embodiment toggle switches may be used to reset the disabled current limiting channels. The current limiting channels may contain circuitry for monitoring the load across the channel and for tripping current a limit switch within the channel. In one embodiment, the circuitry may monitor current flow through the current limit switch. In another embodiment, the circuitry may monitor the current flow through the switch as well as the voltage drop across the switch.
Abstract: A bandgap circuit for generating an accurate and stable reference voltage at low power supply voltages. Stacking of bipolar devices allows for a lower opamp closed-loop gain, which in turn reduces the error voltage contribution to the output due to opamp offset. A CMOS opamp having NMOS input reference transistors coupled with a new bandgap architecture allows a 1.2 v reference (unlike other stacked architectures) without sacrificing low voltage operation. A new trimming method provides for very efficient trimming of bandgap output voltage. Instead of fine tuning the output voltage by trimming ratioed resistors, the output voltage is trimmed by either changing the area of ratioed bipolar transistors, or changing the magnitude of ratioed currents in equally sized bipolar transistors. Therefore, very fine trimming resolution is possible because of the logarithmic function defining the current or transistor size ratios. A new curvature correction method reduces curvature without requiring additional circuitry.
Abstract: The present invention is a driving circuit that comprises a magnetically permeable core, a high voltage secondary winding around the core with the secondary winding being connectable to a device to be powered, a circuit connectable to a D.C. power source and being magnetically coupled to the secondary winding to induce a voltage thereacross sufficient to power a device, a plurality cf connected windings wound around the core, a RC network and a plurality of parallel connected transistors coupled to the windings and the RC network with each respective transistor having a base terminal connected to the RC network by a respective current-variable resistive element, and a first primary winding connected in series with a plurality of second primary windings, and each primary winding connected in parallel with a respective capacitor.
Abstract: A bandgap voltage reference circuit includes a low temperature coefficient of resistance (TCR) tail resistor connected in series with a high TCR tail resistor, and a low TCR correction resistor connected in parallel with the high TCR resistor. The ratio of resistance values for the parallel resistors is selected to produce a correction voltage that essentially cancels a Tln(T) output deviation from temperature linearity, where T is absolute temperature. Matching voltage-temperature characteristics are obtained by selecting a resistor ratio at which the rate of change in the circuit's output voltage, both with and without the parallel resistors, is substantially zero at approximately the same temperature. While the shape of the compensation voltage-temperature curve is determined by the resistor ratio, it is scaled to the magnitude of the Tln(T) deviation by an appropriate selection of absolute resistor values. The correction resistor is preferably a trimmable thin film element.
Abstract: An attentuating voltage-follower circuit has an input stage that buffers an input voltage signal, which varies about a reference voltage, to form an intermediate voltage signal without a DC level shift. A reference stage sets a pivot voltage which is equivalent to the reference voltage so that an attentuated voltage signal can be generated in response to the difference in voltage between the intermediate voltage signal and the pivot voltage across a simple voltage divider stage. The voltage difference between the intermediate voltage signal and the pivot voltage generates a divider current which flows through the voltage divider stage. The divider current, if uncorrected for, would shift the DC level of the intermediate voltage signal. A correction stage senses the magnitude and direction of the divider current and both sources a compensation current and sinks a buffer current which offsets the divider current, thereby eliminating the DC level shift produced by the divider current.
Abstract: A low voltage dimmer is shown with the dimming function being on a primary side of a low voltage transformer. Live voltage feeds through a triac to the primary side of the transformer with the gate for the triac being controlled by a microprocessor. To prevent burnout of the transformer if the secondary load side is open, zero crossing of the incoming signal is determined by the microprocessor. If the time constant between the zero crossing of the live voltage and the charging of a capacitor with resistance being provided by the primary side of the transformer exceeds w predetermined time period, the microprocessor will be inhibited from generating a pulse to fire the triac. When the primary side of the transformer has been opened, the load on the secondary side can be re-established, i.e. light bulb replaced. Power for the microprocessor is from the charging of a capacitor used to provide the triggering signal to the microprocessor. Also the microprocessor may be triggered from remote locations.