Showing papers on "RC circuit published in 1969"

Long period battery-operated aerosol dispenser

Abstract: An automatic aerosol dispenser for producing periodic discharge from an aerosol container at long, accurately determined time intervals on the order of 15 minutes or more and which is completely self-contained, operating on low battery voltage on the order of 3 volts. The time interval is determined by an RC circuit having a long-time constant, with a transistor detectoramplifier, including feedback, for initiating a cycle of motor rotation. The capacitor of the RC circuit is restored to reference condition in an RC circuit of short-time constant. An electromechanical driving arrangement is disclosed which is particularly suited for low-voltage operation.

Ekg amplifying electrode pickup

Abstract: An amplifying electrode pickup for an electrocardiograph (EKG.) device consisting broadly of an impedance converter integrated amplifier circuit potted in a metal shell. The integrated circuit is biased by a nanoamp electrical current. The EKG. signal is sensed by a small sensor plate or disc positioned in a boot or cover and is electrically insulated from the shell. The circuit has a very high input impedance to minimize the effect of skin contact resistance changes, and a very low output impedance to minimize noise pickup by the signal line between the electrode and the EKG. electronics. Electronic circuitry in the potted metal shell also includes a diode voltage clamp and decoupling RC circuits. A multiconductor cable provides shielding, conducts power to the electrode, and transmits the signal from the electrode through an integral coaxial cable. Because of the low (nanoamp) biasing current, signal traces of numerous separate electrodes can be simultaneously recorded without exceeding the maximum permissible current through the human body as established by the American Heart Association.

Design formulas for active RC filters using operational-amplifier biquad

Abstract: Complete design formulas for realising any biquadratic voltage transfer function are given. The configuration uses ten or fewer resistors, two capacitors and four single-ended operational amplifiers. The realisation achieves extremely low sensitivity and can readily be used in realising stable high Q factor active filters up to 100kHz.

Extremely low sensitivity active RC filter

Abstract: A new active RC bandpass filter containing two resistors, two capacitors, and two voltage amplifiers is presented. The Q sensitivities of the filter with respect to the passive elements can be made zero, and the Q sensitivities with respect to the gains of the amplifiersare less than one half.

Light measuring device comprising a plurality of binary circuits for providing a digital representation of photocell output

Abstract: A light measuring device includes successive transistor Schmitt triggers having emitter resistors of successively higher resistances, the collector of the input transistor of each trigger being connected through a diode to the emitters of the next successive trigger. A voltage divider includes a photoconductor and resistor series connected across a battery the voltage across the resistor being applied to the Schmitt triggers. The trigger outputs are connected to lamps and may be connected to relay solenoids which control the insertion of resistances in a shutter timing RC network. The photoconductor may control the charging of a capacitor which is coupled through a high impedance input amplifier to the Schmitt trigger inputs.

Low-sensitivity easily trimmed standard building block for active rc filters

Abstract: Four building blocks have been found that realise the biquadratic transfer function T(s)=K s2 + 2σos + σoo2/s2 + 2σps + σop2 with very low sensitivities to variations in the passive and active components, and with the possibility of trimming σo, ωoo, ωop and ωop independently each by one resistor. The networks may be manufactured in standardised integrated blocks which may be trimmed for specific applications.

Geometric current amplifier

Abstract: A three terminal circuit comprised of two semiconductor transistors of opposite polarity types and two semiconductor diodes. These semiconductors are interconnected so as to provide positive regenerative feedback in a manner which permits achieving highly stable, temperature insensitive circuit characteristics which can be made independent of circuit parameters. The circuit requires no resistors, capacitors or inductors and may be used with particular advantage in integrated circuit form. Use of the circuit as an impedance converter, current generator, voltage regulator and differential amplifier are illustrated.

Active Distributed RC Realization of Low-Pass Magnitude Specifications

Abstract: This paper introduces a design method that allows one to find easily an active distributed RC network transfer function whose magnitude approximates the magnitude of a specified lumped low-pass transfer function. The resulting distributed RC(\overline{RC}) transfer function is a product of simple transfer functions rational in P = \cosh \sqrt{sRC} , each using a different RC product. The overall transfer function is then realized as a cascade of the realizations of the simple transfer functions using a variety of available synthesis techniques. In addition, the characterization of a distributed RC transfer function as a lumped transfer function times a delay factor, as presented herein, permits easy calculation of the transient response of the network. An example of the magnitude approximation is given together with the phase correction made by adding a delay term.

Time-Domain Analysis and Measurement Techniques for Distributed RC Structures. II. Impulse Measurement Techniques

Abstract: Transient analysis for uniform RC structures is considered in this paper A method is presented for determining the parameters of such structures The measurements are obtained using impulse excitations in open‐circuit and short‐circuit configurations The theoretical results obtained predict fairly the experimental results

Log ratio circuit for double beam spectrophotometers

Abstract: A RATIO METR FOR GIVING THE LOG OF THE RATIO OF TWO VOLTAGES. AN RC CIRCUIT IS CHARGED AND ALLOWED TO EXPONENTIALLY DISCHARGE. COMPARATOR MEANS RECEIVE THE TWO VOLTAGES AND THE VOLTAGE OF THE RC CIRCUIT AND PROVIDE OUT PUT SIGNALS WHEN EACH OF THE TWO VOLTAGES IS EQUAL TO THE VOLTAGE OF THE RC CIRCUIT. THE TIME LAPSE BETWEEN SAID TWO SIGNALS CORRESPONDS TO THE LOG OF THE RATIO OF THE TWO VOLTAGES.

Accurate trimming of active rc filters by means of phase measurements

Abstract: A method is described for accurate determination of the locations of poles and zeroes of a transfer function by means of phase measurements. It is especially suitable for trimming of second-degree active RC networks.

Explicit design equations for an active distributed RC network

Abstract: Explicit design and sensitivity equations are given for an active distributed RC network. This network is used to approximate a low-pass transfer function with a pair of complex poles. The expression for the transient response shows that the dominant poles alone yield a good approximation.

RC active network synthesis using an amplifier

Abstract: A new RC active network synthesis procedure for realizing a given open-circuit voltage transfer function is presented. The interconnection of an ideal voltage amplifier of gain greater than unity and two RC sub-networks in a grounded 2-port configuration is considered for this purpose. It is shown that a general rational transfer function of any order can be realized by such a configuration, provided the transfer function does not have zeros on the positive real axis of the s plane. The method compares favourably with other active RC synthesis procedures using a single finite-gain amplifier.

Active RC synthesis using a voltage amplifier

Abstract: A method is presented of synthesizing any voltage transfer function (without positive real axis zeros) using a voltage amplifier and a pair of RC grounded two-port networks.

circuit for generating video markers from potentials to be measured

Abstract: A circuit for generating a marker, such as a stripe, on a television screen to measure a potential, such as a power supply or AGC voltage, features a Schmitt trigger circuit. This circuit has two inputs for the measured voltage and the horizontal flyback pulse. Another embodiment features two trigger circuits, with the second circuit receiving the vertical flyback and another measured voltage. The output of the second circuit blocks the first circuit.

Time‐Domain Analysis and Measurement Techniques for Distributed RC Structures. I. Analysis in the Reciprocal Time Domain

Abstract: The impulse response in distributed‐parameter systems results in a spectrum of delta functions in the time domain for LC structures. It is shown that for RC structures the impulse response results in a spectrum of Poisson‐derived functions in the reciprocal time domain. This isomorphism is exploited for the analysis of RC devices to establish a calculus of Poisson‐derived functions and a transform technique which is essentially the Laplace transform. Applications of this technique to thin‐film devices and minority‐carrier devices are examined and lead to the determination of the transient response for one‐ports and two‐ports that are subject to a wide range of terminations. Illustrative examples of excitations include the impulse, the step, and the ramp, as well as signals generated by the distributed parameter devices themselves. Significant advantages accrue from a spectral description of RC devices in the reciprocal time domain: (1) conceptual, by establishing a physical interpretation based on diffusion phenomena; (2) analytical, by developing a systematic approach to transients paralleling the network function approach in the frequency domain; (3) computational, by expressing the response by a rapidly converging spectrum of functions.

Fluorescent lamp ballast and thermal protective means therefor

Abstract: BALLAST CONTROL FOR ELECTRON DISCHARGE TUBES, SUCH AS FLUORESCENT LAMPS, IN WHICH THE LAMPS ARE CONNECTED TO THE SECONDARY OF A TRANSFORMER HAVING A PRIMARY WINDING INCORPORATING BLOCKING OSCILLATOR MEANS IN WHICH A SINGLE TRANSISTOR HAS ITS OUTPUT CIRCUIT CONNECTED THROUGH ONE PORTION OF THE PRIMARY WINDING TO THE TERMINALS OF A DC SOURCE, AND ITS INPUT CIRCUIT CONNECTED THROUGH ANOTHER PORTION OF THE TRANSFORMER PRIMARY WINDING TO THE TERMINALS OF THE DC SOURCE, THE INPUT CIRCUIT BEING PROVIDED WITH RESISTOR MEANS AND CAPACITOR MEANS WHICH COACT WITH THE PRIMARY WINDING PORTION OF THE INPUT CIRCUIT IN A MANNER TO EFFECT A TUNED RC NETWORK AND AN LC NETWORK HAVING A RELATIVELY HIGH FREQUENCY OF OSCILLATION ACTING TO ALTERNATELY BIAS THE TRANSISTOR INTO CONDUCTING AND NONCONDUCTING STATES FOR UNIFORMLY PULSING CURRENT FLOW FROM THE DC SOURCE TO THE PRIMARY WINDING, AND IN WHICH THERMAL SENSING PROTECTIVE MEANS OPERATES TO AUTOMATICALLY CONTROL THE OPERATION AND NONOPERATION OF THE OSCILLATOR MEANS AND PREVENT THE BALLAST FROM REACHING DANGEROUSLY HIGH TEMPERATURES WHICH COULD RESULT IN THE CREATION OF EQUIPMENT HAZARDS.

Multiloop distributed RC active networks for low parameter sensitivity with low amplifier gain.

Abstract: Multiloop feedback in active distributed RC networks for low parameter sensitivity with low amplifier gain compared to single loop circuits

Frequency discriminator having conduction controlled means

Abstract: A frequency discriminator for frequency-modulated (FM) pulse signals having a steep discriminator characteristic The FM pulse signals are amplitude limited, differentiated and then rectified The time constant of a subsequent RC circuit and the fixed bias applied to the RC circuit are so selected to produce a linear sawtooth signal having a duration equal to the period of the FM pulse signals so that a subsequent transistor is always blocked at pulse frequencies above fmax, unblocked momentarily at pulse frequencies between fmin and fmax to pass pulses with an amplitude increasing in the negative direction linearly as the frequency decreases, and passes constant maximum negative going amplitude pulses at pulse frequencies below fmin The discriminator output voltage is obtained by peak rectification of the pulses passed by the transistor In another disclosed embodiment, the discriminator output voltage is passed through a low pass filter to provide the bias for the RC circuit

Electronic current to voltage converter

Abstract: The invention is an electronic current to voltage converter circuit including a temperature compensating circuit, a differential amplifier circuit, a feedback circuit, and an input voltage zero adjust circuit for establishing and maintaining the input voltage signal to the circuit substantially zero to permit virtual short circuit current measurements of signals developed by a current generating device.

Active RC bandpass and highpass network

Abstract: An active RC circuit is described, which can be used as a second-order bandpass or highpass filter. Its sensitivity is independent of the Q factor and very low.

High speed function tester for integrated circuits

Abstract: The test apparatus is composed of a clock signal generating circuit, a patterned pulse generating circuit operated in synchronism with the clock signal generating circuit, with the output of the patterned pulse generating circuit being furnished to an integrated circuit to be tested, a reference voltage generating circuit, a comparator circuit to compare the output pulses from the integrated circuit to be tested with the output from the reference voltage generating circuit, a function pulse generating circuit synchronized with an output from the comparator circuit, a circuit for detecting coincidence between the output from the comparator circuit and the output from the function pulse generating circuit, and a displaying circuit to display the output of the coincidence detecting circuit, whereby the validity of the integrated circuit is determined from the coincidence of the output pulses from the integrated circuit with the expected pulse patterns obtained from the function pulse generating circuit

Frequency conversion system

Abstract: In many dynamic control systems, there is a need to rapidly and accurately convert the frequency of an input signal into a voltage proportional thereto. At a preselected time in a cycle of an input signal, a plurality of capacitors are charged to a reset level. After a fixed delay from the preselected time, each of the charged capacitors begins to discharge at a rate determined by the value of an RC network to generate a voltage signal that decays exponentially. The exponentially decaying voltage for each of the plurality of capacitors are summed together to produce a voltage that varies inversely with frequency. This voltage is the input signal to a sample and hold circuit. At the completion of one cycle of the input signal, the value of the voltage that varies inversely with frequency is read and stored as a voltage representative of the frequency of the input signal. Higher voltages correspond to fast frequency signals and lower voltages correspond to slow frequency signals. Conversion of a frequency takes place upon completion of a sampled cycle.

Alternating current controller with start-up delay

Abstract: An AC controller connects a load to an AC voltage source and has a control unit for providing output control pulses in synchronism with the voltage of the source. An RC circuit connected to the control unit has a load capacitor and a load resistor for controlling the phase position of the control pulses in accordance with the time constant of the RC circuit.

A Comparison of Various Filter and Discriminator Techniques on Timing with Ge(Li) Detectors

Abstract: An experimental examination of the effect of several filters and two discriminator techniques on the time measurement of the signals from coaxial Ge(Li) detectors is presented in this paper. The signal to the filters and discriminators was obtained from the output of the charge-sensitive preamplifier in order not to degrade the energy resolution of the system. The discriminators used were a level discriminator for leading-edge discrimination and a fast zero-crossing discriminator. The filters examined for leading-edge discrimination were four RC time-invariant and four RC time-variant filters, and the filters for zero-crossing discrimination were three time-invariant RC filters. A comparison of time-invariant and time-variant filters reveals two advantages of the time-variant filter. These advantages are smaller timing errors and lower discrimination levels. The lower discrimination levels allow the reduction of energy dependent timing errors. Likewise, zero-crossing discrimination provides several improvements over leading-edge discrimination. By a compensation method, timing errors due to charge collection variations are reduced; and, due to the invariancy of the zero-crossing point as a function of amplitude, energy-dependent timing errors are also reduced.

Monostable and astable multivibrator apparatus including differential amplifier, rc network and switch means for initiating and terminating output pulses

Abstract: Monostable multivibrator apparatus (one shot) is disclosed which was conceived to fill the need for a reliable, stable, low-power pulse generator that is not sensitive to temperature and supplyvoltage variations. In one embodiment, two of the monostable multivibrators are connected in a closed-loop configuration for use as an astable low frequency clock generator. To provide stability the monostable includes a differential amplifier having one input connected to a reference input voltage (midpoint of a resistance voltage divider), the other input receiving a pulsewidth determining voltage from a capacitance-resistance network. Switch means, which functions to initiate and terminate output pulses, is activated by an external signal to initiate pulses and by the output of the differential amplifier to terminate pulses.

Pulse-width discriminator having conduction controlled means

Abstract: A pulse-width discriminator providing a very steep discriminator characteristic. The width modulated input pulses limited to a constant amplitude are rectified and applied to an RC time constant circuit prior to being applied to a transistor whose conduction is controlled by resultant linear sawtooth signals whose duration are equal to the duration of the input pulses. The time constant of the RC circuit, the bias potential applied to the RC circuit and the bias potential applied to the transistor, by means of a Zener diode coupled between the RC circuit and base of the transistor, are so selected that the transistor is blocked for pulse widths below timin, momentarily unblocked for pulse widths between timax and timin to pass pulses having amplitudes increasing linearly in the negative direction as the pulse width increases, and saturated for pulse width above timax to pass pulses having a negative going constant maximum amplitude. The discriminator output voltage is obtained by peak rectification of the pulses passed by the transistor. In another disclosed embodiment, the discriminator output voltage is passed through a low pass filter to provide the bias potential coupled to the RC circuit.

The Values of the Parameters of a Distributed RC Null Network

Abstract: Distributed RC notch filter normalized constants for dominant and nondominant transmission zero