Abstract: Disclosed are solid-state potentiometers having high resolution and high accuracy. An exemplary potentiometer has a first main terminal, a second main terminal, a wiper terminal, and a resistor stack having a plurality M of resistors coupled in series to one another at a plurality of M−1 internal nodes. Each of the resistors in the stack has substantially the same value of RS ohms. The potentiometer further has a first variable resistance network coupled between one end of the resistor stack and the potentiometer's first main terminal, and a second variable resistance network coupled between the other end of the resistor stack and the potentiometer's second main terminal. The first variable resistance network has a variable resistance value R1 which varies between zero ohms and RP ohms. The second variable resistance network has a variable resistance value R2 which is maintained substantially at value of (RP−R1).

Abstract: An electrical signal supply apparatus independently controls and regulates voltage and current in supplying microampere currents to skin tissue of patients. The apparatus enables operators to select a desired voltage level independent of the requirement to maintain current through the skin tissue at a relatively constant level. The apparatus includes a switching regulator in combination with an electric voltage doubling network and potential divider network to enable the supply of increased voltages.

Abstract: A power supply circuit for an integrated-circuits chip includes variable resistors for establishing an internal voltage for the chip. The internal voltage is variable with the variable resistors and compared by a comparator to a test voltage supplied from an external test circuit. A first buffer amplifier, powered by an externally supplied voltage, amplifies the output of the comparator to produce output voltages of opposite polarities. A second buffer amplifier, powered by the externally supplied voltage, amplifies the output voltages of the first buffer amplifier to supply an output voltage to the test circuit. In a modified embodiment, a second voltage source is additionally provided to establish a second internal voltage higher than the internal voltage produced by the first reference voltage source. The first buffer amplifier is powered by the second internal voltage, instead of by the first internal voltage, to amplify the output of the comparator.

Abstract: In a multi-valued voltage generating circuit including a voltage divider connected between first and second nodes and formed by a series of resistors, and an output circuit, connected to the first and second nodes and nodes of the resistors, for selecting one of voltages at the first and second nodes and the nodes of said resistors and generating the one of voltages at an output terminal, first and second control voltage circuits are connected to the first and second nodes to control an output voltage at the output terminal to compensate for fluctuations of the threshold voltages of MOS transistors of the output circuit. Also, first and second current control circuits are connected to the first and second nodes, to control currents flowing through the series of resistors to control a difference in potential between the first and second nodes at a certain value and to compensate for the fluctuation of the resistance.

Abstract: Systems for controlling the current consumption of an integrated circuit chip and the like so as to reduce the inductive voltage drops occurring over the power supply lines within the chip and power supply lines to the chip are disclosed. The systems according to the present invention are applicable to circuits having two or more sub-circuits formed on a semiconductor substrate, each sub-circuit having two or more power supply inputs. An exemplary system comprises two or more current shunting elements formed on the substrate, with each current shunting element coupled in parallel with the power supply inputs of a selected sub-circuit. The system has at least two main power supply lines formed on the semiconductor substrate, with each selected sub-circuit having each of its power supply inputs coupled to a main power supply line. A current shunting element may comprise a Zener diode, an active shunt circuit, or equivalents thereof.

Abstract: A high-power modulator includes a plurality of means for limiting voltage and a plurality of controllable switches. Each of the switches is connected in parallel with a different one of the voltage limiting means to form a plurality of parallel pairs. Each of the parallel pairs is connected to each other in a series combination. A first parallel pair in the series combination can be connected to a main power source, and a last parallel pair in the series combination can be connected to a load. Each of the switches is switchable from an off or open position to an on or closed position.

Abstract: A dynamic braking system resistor for stabilizing a power system during power system disturbances includes a braking resistor for coupling with a power system bus. A controller monitors a power system parameter, such as the speed of a generator coupled with the power system bus, and determine therefrom a thyristor control signal. The controller uses the power system parameter to establish a desired modulation and then provides a bias to the desired modulation. The controller conditions the biased desired modulation signal to provide the thyristor control signal. A thyristor valve responsive to the thyristor control signal couples the braking resistor with a ground potential. A method is also provided of damping subsequent oscillations on a power system following a power system disturbance using the dynamic braking resistor.

Abstract: A signal level attenuating device having an analog attenuator and a digital attenuator which respectively include resistance attenuators. The resistance attenuators have the same attenuating characteristics and are mutually coupled. When one of the resistance attenuators is adjusted, the other of the resistance attenuators is simultaneously adjusted so that an analog signal and a digital signal respectively entered therein are attenuated at an identical attenuating factor. The digital attenuator further comprises an A/D convertor, a coefficient generator and a multiplier. The resistance attenuator in the digital attenuator attenuates a reference voltage and sends it to the A/D convertor. The coefficient generator computes an attenuation coefficient by which the digital signal entered therein is to be multiplied, based on an output of the A/D convertor. The digital signal is multiplied by the attenuation coefficient in the multiplier.

Abstract: A variable impedance circuit for use in an external circuit is disclosed. The impedance value is selected by an external circuit. The variable impedance is generated between two terminals which are accessible for connection to external circuitry. The impedance provided between these terminals is determined by a control circuit responsive to electrical signals coupled to the control circuit. An internal register in the control circuit stores a value which specifies the impedance between the two terminals. The stored value is copied into a programmable nonvolatile read-only memory in response to a first predetermined electrical signal. Similarly, the value stored in the read-only memory is selectively copied into the internal control circuit register in response to a second predetermined electrical signal.

Abstract: A potentiometric circuit arrangement 30 is based on a resistive potentiometer tarck 11 with a capacitively coupled `wiper` 14', the resistive track being driven by switched alternating voltages of +/- V at 12 and -/+(X-V) at 13, where X is a reference voltage and V is the output of an integrator 15 to which the voltage sensed by the elecrode 37, and rectified at 36, is applied. A null voltage point establishes itself at the position of the electrode and stabilizes the integrator output at a d.c. voltage proportional to the distance of the `wiper` from the track end 12. Any `wiper` displacement taps a non-null signal which integrated applies new voltages to the track until the null point is re-established at the `wiper` position. The capacitive pick-up enables a potentiometer-type voltage output with less wear of the track, less drag against motion and less electrical noise, and electronic differentiation (27) of the position signal to give a rate signal.

Abstract: A non-contacting potentiometer includes a resistor and a movable probe which capacitively couples AC signals applied to the resistor to an output terminal. A closed loop control circuit is coupled to the resistor and the probe to compensate for variations in gap spacing between the probe and resistor.

Abstract: A voltage regulator that reduces the voltage output of a generator to make it appropriate for use with an external load. The voltage regulator includes a starting unit for use with on-demand generators to cause the on-demand generator to start without presenting a risk to the external load.

Abstract: A constant voltage generator includes a resistance adjustable resistor having a series connection of a main resistor and sub-resistors, a circuit cooperating with the series connection to produce a constant voltage, a plural number of transistors having a collector-emitter path connected to corresponding one of the sub-resistors, and a plural number of semiconductor memories applying voltages to bases of the transistors, respectively, in accordance with stored information, whereby the resistance of the resistance adjustable resistor is adjusted by the stored information to control the output constant voltage.

Abstract: A plurality of controlled avalanche semiconductor elements, are connected in series and are irradiated with a controllable quantity of light to form circuits which in principle can switch an unlimited high voltage or can control such a voltage. Dissipating auxiliary means to obtain a uniform voltage distribution cross the circuit are not required. As a light source, light-emitting diodes can be used so that the elements can be controlled at a low-voltage level and with DC separation the circuit can be used in high-voltage amplifiers, high-voltage regulators or high-voltage stabilizers, deflection voltage generators, high-voltage switches in X-ray apparatus, lasers, ignition systems in combustion engines etc.

Abstract: A calibratable voltage divider made by thin-film or thick-film technology formed by a flat film is an ohmic voltage divider resistor connected to have current flow through it. At least one tap is provided to tap off a desired divider voltage. The ohmic voltage divider resistor includes a single, coherent first resistance zone (10), which has one area for supplying current and another for taking current away, each being connected with a respective connection conductor (11, 12). The tap is made in the form of a second resistance zone (13) connected with the first resistance zone (10) between the current supply, and current drainage areas, and a take-off electrode (14) is attached to the second resistance zone (13). As needed, one or two cuts (16, 17), which intersect the equipotential lines are made to partially separate the second resistance (13) from the resistor (10) zone extended far enough that the potential attains the desired value at the take-off electrode (14) of the tap.