Abstract: A potentiometer with the extremely small relative uncertainty of a few parts in 109 has been developed by utilizing the property that a Josephson junction generates a precise voltage that is variable with frequency and step number. The evaluated total uncertainty is 2.5 × 10-9V for measurements at the 1-V level. This small uncertainty is attributed to the generation of a higher than normal Josephson voltage, that is, on the order of 100 mV.

Abstract: A charge control microcomputer is provided for a vehicle charging system to control the reference voltage employed by the voltage regulator so that a suitable battery charging voltage is generated at all times. The microcomputer processes charging system data such as the battery output voltage, the generator output current, etc., and at least one engine parameter from an engine control microcomputer to derive the most suitable reference voltage for the voltage regulator.

Abstract: The differential-pressure measurement apparatus consists of a capacitive differential-pressure sensor 1 having two measurement capacitors C1 and C2 whose capacitance values vary with the differential pressure acting on the membranes 2 and 3, of two integrating elements 9 and 10 which are fed back via the measurement capacitors C1 and C2, and which convert their capacitance values into measurement signals, and of a computing element 12 which calculates the differential pressure from the measurement signals. In order that the sensitivity of the differential-pressure measurement apparatus can be kept free of defects and constant in a simple manner, the integrating elements 9 and 10 are supplied from a controllable oscillator 11, and a temperature-dependent control voltage is obtained from the measurement signals via a computing circuit 13, which control voltage, after comparison with a constant reference voltage which can be entered via the connection 15, provides follow-up control of the oscillator 11 in such a manner that the control voltage equates to the reference voltage.

Abstract: A device for signalling a specific charge condition of an accumulator battery (B) comprises a comparator circuit (C) for comparing the battery voltage (V B ) with a reference voltage. A switching circuit (G 2 , G 13 ) is controlled by the comparator circuit and an indicator (L 1 , L 2 , L s ) is in turn controlled by the switching circuit. A memory circuit (FF) ensures that the indicator remains energized for a specific time interval after the apparatus has been switched off.

Abstract: A new single-chip 16-bit monolithic digital/analog converter (DAC) with on-chip voltage reference and operational amplifiers has achieved /spl plusmn/0.0015% linearity, 10 ppm//spl deg/C gain drift, and 4-/spl mu/s settling time. Novel elements of the 16-bit DAC include: the fast settling open-loop reference with a buried Zener, a fast-settling output operational amplifier without the use of feedforward compensation, and a modified R-2R ladder network. Thermal considerations played a significant role in the design. The DAC is fabricated using a 20-V process to reduce device sizes and therefore die size. All laser trimming including temperature drift compensation is performed at the wafer level. The converter does not require external components for operation.

Abstract: A sample of the voltage magnitude across a load, connected in series with an A.C. source and a load-current-flow-control subcircuit, is taken during at one of the time intervals when load current flows during a source waveform cycle. The sampled load voltage is compared to a reference level and the difference in magnitude between the sampled and reference voltages is integrated, with respect to time, to provide an adjustment signal. The adjustment signal is provided to a subcircuit for timing the conduction period of the load-current-flow-control subcircuit, by varying the conduction-termination time after each conduction-commencement (at each source waveform zero-crossing) to vary the selected one of the half-cycle-average (mean absolute deviation--MAD) or RMS voltage magnitude across the load to a value such that the sampled load voltage magnitude is substantially equal to the selected reference voltage magnitude. Several presently preferred embodiments are described for controlling the load magnitude in accordance with this method.

Abstract: A CMOS substrate bias generator including a PMOS charge pump and a regulator for controlling the operation of the substrate bias generator. The substrate bias generator further includes an input circuit, a reference circuit to provide a reference voltage, a comparison circuit to compare voltage levels between the input and the reference circuit, and output circuitry to provide a signal from the comparison circuitry to the substrate bias generator. The comparison circuitry further includes hysteresis circuitry tending to preserve voltage at a node in the comparison circuit despite an imbalance between the input circuit and the reference circuit.

Abstract: An electronic clutch for a multispeed electric tool includes a voltage sensor having a D.C. voltage output proportional to the current absorbed by the tool's motor and dependent on the motor operating temperature. A comparator compares this D.C. voltage with a suitably generated reference voltage, and if the former exceeds the latter it blocks the oscillation of an oscillator which via a power circuit controls a triac provided in the motor power supply circuit. Blocking the oscillator causes the deactivation of the triac, and thus stops the motor. The proportionality constant of the D.C. voltage, or that of the reference voltage, can be varied as a function of the tool operating speed. For this purpose, the voltage sensor or, respectively, the reference voltage generator includes a voltage divider in which resistors are provided which can be cut in or out by means of electric contacts controlled by the tool's speed change mechanism.

Abstract: A method is provided for manufacturing a reference voltage generator device which detects a voltage corresponding to an energy gap of a semiconductor, or a voltage of a value close thereto, or a voltage based on an energy level of a semiconductor, and generates the detected voltage as a reference voltage. The reference voltage is generated by detecting a difference of threshold voltages of first and second insulated gate field-effect transistors (IGFETs). Gate electrodes of the first and second IGFETs are formed on gate insulating films which are formed on different surface areas of an identical semiconductor substrate under substantially the same conditions. The gate electrodes of the first and second IGFETs are respectively made of two semiconductors which are selected from among a semiconductor of a first conductivity type, a semiconductor of a second conductivity type and an intrinsic semiconductor made of an identical semiconductor material, but which have Fermi energy levels of values different from each other.

Abstract: In this paper, a new method is described which uses switched capacitor techniques to implement cyclic A/D and D/A converters. By periodically modifying the reference voltage to compensate for the nonideal signal transfer loop gain, it is possible in principle to build analog-digital (A/D) and digital-analog (D/A) converters whose linearity is independent of component ratios and which occupy only a small die area. These converters require two moderate-gain MOS operational amplifiers, one comparator, and a few capacitors.

Abstract: A digital-analog converter characterized in that reference voltage is divided by a first string-like resistor array (11, 105, 202), whose two adjacent outputs are selected by a first switch array (13, 107, 204) depending upon the contents of upper bits of a digital signal and applied to the both ends of a second string-like resistor array (17, 110, 211), and one of switches in a second switch array (18, 113, 214) is selectively turned on responsive to the contents of lower bits of said digital signal to pick up one of the divided voltages of said second resistor array (17, 112, 211)

Abstract: A multi-phase DC-to-AC voltage boosting converter suitable for use as the primary stage of power isolated, high output voltage DC-to-DC voltage converters. The converter is comprised of a plurality of transformer primary windings electrically interconnected in a single loop mesh configuration and a plurality of voltage boosting channels operatively associated with the respective primary windings and commonly connected to a low voltage power source. The phase channels are operated so as to periodically provide a boosted voltage potential to the primary windings in a continuously cycling, multi-phase synchronous relation to one another so that a corresponding multi-phase, high-voltage AC potential is provided across each of said primary windings. Various conventional AC-to-DC converters and voltage multiplier circuits may be inductively coupled to the transformer primary windings to provide a wide variety of highly efficient low-to-high voltage DC-to-DC boost converters.

Abstract: A differential voltage amplifier comprises a first and second capacitive coupling type amplifiers in each of which an autozeroed mode period for setting an operating point and a signal amplifying mode period for amplifying an input voltage are alternately set up, and the autozeroed mode periods in said first and second amplifier are shifted from each other, first and second mode selector for alternately setting up the autozeroed mode and the signal amplifying mode in the first and second capacitive coupling type amplifiers, first and second signal selectors provided corresponding to the first and second capacitive coupling type amplifiers, the first and second signal selectors alternately selecting a reference voltage and an input signal voltage to apply the selected signal to the first and second capacitive coupling type amplifiers, the first and second signal selectors further selecting the reference voltage corresponding to the autozeroed mode periods of the first and second capacitive coupling type amplifiers and the input signal voltage corresponding to the signal amplifying mode periods, and a selector for selecting the amplified signal output from the first and second capacitive coupling type amplifiers when the first and second capacitive coupling type amplifiers are in the signal amplifying mode.

Abstract: This invention is an apparatus and method created around a specialized micomputer attachable to and addressable to each thermister in an array of thermisters used to measure temperature in the sea. The invention provides a number of options so that the same model of microcomputer can be adapted to several different modes of operation and used to monitor a variety of other sensors that have electrical resistance, voltage or current as outputs. Alternate modes of operation for resistive sensors are presented where a number that fixes the measurement as a fraction of the dynamic range of the variable being measured is determined. The system includes the circuits and memory needed to adapt it to any of a variety of sensors measuring physical quantities. The microcomputer contains a counter that can be incremented at several rates, a voltage comparator which can be used to interrupt the counter at a number that represents the measurement, input/output buffers for connections with a remote master control unit whereby command instructions and data can be relayed to and from the microcomputer, and a voltage reference source.

Abstract: In a circuit arrangement for controlling the operating temperature of the heating coil of an electric soldering iron, the resistance variation of the heating coil itself is to be evaluated at lowest possible cost of circuitry and doing away with a thermocouple sensor that used to be arranged in the region of the soldering bit or of the heating coil, at high mechanical cost. To this end, a precision resistor is inserted in the heating circuit and a TRIAC switching element connected between the latter and the heating element, which is switched open by a comparator circuit as a function of the voltage drop at the precision resistor or which lets through only the pulses of a pulse generator circuit required for measuring the switch-on threshold, which pulse generator circuit is synchronized via a null detection circuit for null passage of the AC voltage. The voltage drop is further compared with a preset voltage and when it is reached an integration capacitor is charged, the voltage of which controls the comparator in proportion to a reference voltage. The TRIAC is switched on as long as the voltage at the output of the integration exceeds the reference voltage, and is switched off as long as this voltage is lower than the reference voltage. In the latter case the integration capacitor forms a time function element for the reheating of the heating coil.

Abstract: A phase control ballast in which a reactor and a triac are connected in series with an hid discharge lamp across an ac voltage source. A supra-linear converter connected to a rectifier-filter provides a reference voltage which is a supra-linear function of the source voltage. A ramp generator provides a ramp voltage climbing at a constant rate. At the instant when the ramp voltage exceeds the level of the reference voltage, a comparator circuit provides a signal to the gate of the triac which turns it on. A triac state detector responds to the turning on of the triac in either polarity by dropping the ramp voltage to zero and holding it at zero until the triac turns itself off.

Abstract: A scan mode keying circuit comprises a voltage divider having a plurality of series-connected resistors with taps therebetween to develop a plurality of graduated voltages at the taps. A comparator having first and second input terminals is provided for generating a coincidence output when a match occurs between voltages applied to the input terminals. Plural of manually operated keys are connected to the taps for selectively applying the graduated voltages to the comparator first input terminal. A control circuit generates and applies a series of recyclic waveforms of time-varying reference voltage to the comparator second input terminal. Responsive to the coincidence output a datum representing the instantaneous value of the reference voltage is stored into a memory and compared with subsequently generated datum to verify that one of the key has been operated when a match occurs therebetween. If they fail to match, the control circuit proceeds to detect when the most recent datum is greater than the previous datum to verify that the operated key has been turned off.

Abstract: A switching regulator is provided with a separate or isolated d-c output for operating the switching pulse generating circuits. A large value resistor coupled between the d-c input line and the isolated d-c output will charge the filter capacitor to a higher than normal voltage. A zener diode string is coupled across the filter capacitor. The zener diodes in combination have a higher than nominal zener voltage. The diodes will respond to the capacitor voltage and develop a starting pulse that initiates the power supply when it is first energized.

Abstract: An amplifier arrangement for an acceleration pick-up (10), in particular a piezoelectric acceleration pick-up for restraint systems in motor vehicles is proposed, the output signal of the amplifier arrangement being compared, for the purpose of offset compensation, in a comparator (27) with a reference voltage in a fixed or variable time slice. Depending on the output signal of this comparator (27), the output current of a current source (35) is increased or decreased in the time slice, and fed to the amplifier input for the purpose of compensation. It is possible in this way for the offset drift to be compensated via the time and temperature, even in the case of cheap acceleration pick-ups.

Abstract: @ A memory circuit provided with a control circuit which controls operations of the memory circuit in such a manner that the memory circuit is automatically set in a stand-by state when a value of a power voltage is reduced in absolute value irrespectively of a control signal from the outside and which consumes no DC current is disclosed. The control circuit comprises a load element coupled between first and second terminals, a series circuit of first and second field effect transistors coupled between the second terminal and a third terminal, the first transistor being controlled by the control signal, the second transistor being adapted to be conducting when a value of the power voltage is sufficient for allowing a normal access operation, a means for connecting the first terminal to one of the power voltage and a reference voltage, and a means for connecting the third terminal to the other of the power voltage and the reference voltage.

Abstract: A hot-wire arc welding apparatus comprises a non-expendable electrode, means for supplying a current to initiate an arc between the nonexpendable electrode and a workpiece, an arc current control means for controlling the current from the supplying means, a wire feed means for feeding a filler wire into the arc, a wire feed control means for controlling the wire feed means to feed the filler wire at a given rate of feed, a voltage applying means for applying a voltage between the filler wire and the workpiece, a wire voltage control means for controlling the voltage from the voltage applying means, and a reference voltage generator for generating an output voltage which increases gradually or incrementally with time, each of the arc current control means, the wire feed control means, and the wire voltage control means being connected to the reference voltage generator and responsive to the output voltage therefrom for controlling the operation thereof. A delay circuit such as an integrator may be connected between the reference voltage generator and the wire feed control means for applying a delayed output voltage to the latter.

Abstract: A vehicle charging control system includes a charging control microcomputer for performing arithmetic operations upon input engine or charging system parameters to derive the most proper operating voltage for the charging system. The voltage regulator includes a comparator which receives its reference voltage from the charging control microcomputer. An engine control microcomputer which controls, for example, the air/fuel ratio also outputs data to the charging control microcomputer for use thereby in controlling the reference voltage. The charging control microcomputer may perform diagnostics on the charging system and output the results thereof to a suitable indicator.

Abstract: A CMOS D/A converter for use in a voltage-mode and having complementary-driven switch pairs for V ref and A gnd respectively. The "ON" gate voltage of the A gnd switch is adjusted in accordance with the value of V ref , to give switch V GS equality and therefore "ON" resistance matching with the V ref switch over a wide range of reference voltage. Circuits are shown for developing the A gnd gate voltage varying with V ref .

Abstract: A power multiplexer switch for alternatively coupling a supply or standby voltage line to an output voltage line comprises a first switching means for coupling an intermediate node to a common voltage line. Second switching means are responsive to the first switching means for coupling the supply voltage line to the output voltage line. Third and fourth series switching means connected to the intermediate node couple the standby voltage line to the output voltage line when a voltage on the standby voltage line exceeds that on the supply voltage line.

Abstract: A power voltage generator is supplied with the power voltage applied directly and via an ignition switch from a battery. The power voltage generator always supplies a power source to a computer equipped with a back-up memory and supplies to a comparator a power voltage signal from the power voltage generator when the ignition switch is turned on. The comparator compares a predetermined voltage signal with the power voltage signal from the power voltage generator. When the power voltage signal is higher than the reference voltage signal, the comparator issues a command to execute the program to a computer. The computer issues a write command to enable the back-up memory when it is judged that the increased voltage is stabilized, to thereby set up a write enable mode. If the power voltage signal drops when the ignition switch is turned off, this condition is detected using the output signal of the comparator. And it is judged whether or not the command to the back-up memory is being executed. If the command is being executed, the write enable state is continued until the command execution ends. The data write to the back-up memory is discontinued when the command execution ends.

Abstract: A voltage compensating driver circuit uses a resistor and a zener diode to remove the effect of potential difference between logic ground and power ground on the comparative function of the circuit and the supply voltage is applied as an input to the comparative function.

Abstract: A low fuel indicator system 10 for a motor vehicle comprises a light-emitting indicator 12 which is energized or de-energized by an output signal derived from a voltage comparator 14 which receives a reference voltage from a reference voltage source 20 and a variable voltage signal from a time delay circuit 22, which variable voltage signal is derived from a voltage signal generated by a fuel level sensor in a fuel tank of the vehicle. The light-emitting indicator 12 is energized when the fuel level in the fuel tank falls below a predetermined low level, and time delay circuit 22 operates to isolate the voltage comparator 14 and light-emitting indicator 12 from temporary variations in fuel level produced by "fuel-slosh" in the fuel tank caused by variations in the motion or orientation of the motor vehicle. In a preferred embodiment of the invention, a time delay override circuit 24 is included which is operable upon switching on the ignition circuit of the vehicle to energize the light-emitting indicator 12 if the level of fuel in the fuel tank is above said predetermined low level but below a second predetermined level corresponding approximately to the fuel tank being a quarter full.

Abstract: PURPOSE:To enable to stabilize the output DC voltage to the wide input/output variations by connecting a resonance condenser of a DC/DC converter in parallel with a variable inductance and controlling it. CONSTITUTION:Switching elements 3, 4 which turn ON and OFF are connected in series with both terminals of input DC power sources 1, 2, and a resonance condenser 7 and the primary coil 5a of a conversion transformer 5 are connected in series with the intermediate points between the elements 3, 4 and the source 1, 2. The output voltage from the secondary coil 5b of the transformer 5 is applied through a rectifier 8 and a capacitor 9, is then applied to a comparator 12, which compares it with a reference voltage ES. This compared difference output is supplied to a DC current controller 13 and the DC current in response to this signal is applied to a variable inductance element 11, the inductance between the input and output terminals A and B is controlled, the DC current is also applied to a sorting circuit 14, thereby controlling the switching frequency of the elements 3, 4.

Abstract: PURPOSE:To obtain accurate limiting function in a high voltage power source by allowing a load current control loop which limits a load current at the prescribed level at the time of raising a load impedance to relate to a control loop which maintains the output voltage constant. CONSTITUTION:A load current detected by a resistor R16 is compared by an operational amplifier OA3 with a reference voltage. When the load current exceeds the prescribed value, a transistor Tr2 is turned ON, thereby interrupting the input of the primary side power feeding circuit of a converter transformer T1 by the output of an operational amplifier OA1. When the transistor Tr1 is turned ON, charge stored in a condenser C3 is discharged, thereby again inverting the output of the comparator OA3, and turning the transistor Tr1 OFF. When the load current tends to exceeds the limit value in this manner, the output level of the comparator OA3 is inverted, the transistor Tr1 is, in turn, repeated to conduct ON and interrupt OFF, thereby maintaining the limit value.