Showing papers on "Decoupling capacitor published in 1972"

Body organ stimulator

Abstract: The output circuit of an electric stimulator is connected to an organ such as the heart through a coupling capacitor. A semiconductor switch is triggered with a short pulse so that it partly discharges the capacitor and stimulates the organ. Immediately following the turn off of the first switch, a second switch is activated to recharge the capacitor to its initial state during which time reverse current is delivered momentarily to the heart. In one embodiment, after the first switch turns off to terminate the discharge of the capacitor which stimulates the heart, the current through the heart is reversed immediately by recharging the capacitor through a diode which is connected to a supply line and is in series with the capacitor and the heart. Turn-off of the first switch starts the diode conducting heavily. A high input impedance detector determines whether there is a natural electric signal on the organ and turns on a generator which provides the trigger pulse if there is no natural signal. The circuit is arranged so that the detector and output circuit present a high impedance to the organ.

Power regulation by means of a switched capacitor

Abstract: A bridge of four solid-state switches with a capacitor in one diagonal is connected in series between the supply and the load. The switches (thyristors) periodically reverse the current-flow direction through the capacitor. The load power is controlled by varying the switching frequency. The device may be used for the control of direct current and alternating current.

Electric power supply system using back-up capacitor

Abstract: Herein disclosed is an improved d-c power supply system which comprises a d-c power source, a first rectifier serially connected to the power source, and series connection composed of a protective resistor and a back-up capacitor, the series connection being connected across the first rectifier and the power source, and the protective resistor being bypassed by a second rectifier so that a discharge current from the back-up capacitor flows through the second rectifier. The power supply system further comprises means for producing information signals representing condition of the back-up capacitor.

Reactive power compensation control system

Abstract: A reactive power compensation control system is provided for a three phase ac electric power supply system which exhibits power factor changes when subjected to large reactive draws by dynamic reactive loads. The control system comprises four capacitor banks switchable in or out of the power system by solid state switches. Each capacitor bank comprises three delta connectible capacitors, one capacitor for each pair of phase lines, and each capacitor is switched by one solid state switch. Each solid state switch comprises a pair of inverse parallel connected SCR''s. Each solid state switch is controlled by an individual firing circuit which comprises a charging circuit (for operating the charging SCR) and a discharging circuit (for operating the discharging SCR). All 12 firing circuits are controlled by a control circuit which comprises a KVAR transducer coupled to the power supply system for sensing reactive power conditions therein and ON and RUN circuits which operate the firing circuits.

Low impedance capacitor discharge system and method

Abstract: A low impedance capacitor discharge ignition system and method in which a supplemental capacitor is utilized on the secondary winding side of the high voltage transformer to avoid the impedance of the transformer in sustaining the gap ionization potential of the ignition device.

Analog to pulse rate converter

Abstract: An analog to pulse rate converter includes an integrator circuit in which the integrator capacitor is charged at a rate corresponding to the level of an input signal. A logic control circuit causes the capacitor to discharge at a fixed rate during a fixed portion of the clock period whenever the capacitor charges above a predetermined charge level. Output pulses occur during each discharge cycle. The average frequency of the output pulses indicates the level of the input signal.

Open circuit detection apparatus for thermocouple circuits

Abstract: A circuit for detecting an open circuit condition of a thermocouple using a storage capacitor to transfer a thermocouple output signal to an analog to digital converter circuit and pulse signal means arranged to apply a pulse signal to the capacitor when the capacitor is connected to the analog to digital converter for storage by the capacitor. The stored pulse signal is subsequently discharged by a thermocouple circuit which is a complete circuit. An open-circuited thermocouple circuit will not discharge the pulse signal stored on the capacitor, and the total stored signal will accumulate during subsequent successive switching of the capacitor between the open-circuited thermocouple circuit and the analog to digital converter until a sufficient charge has been accumulated to energize an alarm signal connected to the analog to digital converter.

Device for generating a high voltage supply

Abstract: A voltage generator comprises a capacitor and positive and negative power supply rails. Normally non-conducting first and second field-effect transistors are arranged to isolate the capacitor from the power supply rails in the non-conducting state thereof and to connect the power supply rails to respective plates of the capacitor in a conducting state thereof. Means are provided to trigger the first and second transistors into the conducting state for a limited period to charge the capacitor and then isolate the capacitor when the transistors revert to their normal state. A normally non-conducting field-effect transistor is operative, on isolation of the capacitor subsequent to charging thereof, to adopt a conducting state in which such third transistor connects one of the plates of the capacitor to the opposite supply rail to that to which it can be connected by the respective first or second transistor, whereby to produce an enhanced voltage on the other capacitor plate. The enhanced output is delivered across an output capacitor connected via a fourth field-effect transistor to the said other plate of the first mentioned capacitor.

Device for controlling exposure time in a camera

Abstract: A device for controlling exposure time in a camera includes a photoelectric converter circuit for converting the intensity of light passed through the camera''s photo-taking lens into a voltage, a storage capacitor for storing the voltage, a magnet driving circuit for driving a magnet which controls the exposure time of the camera''s shutter in accordance with the voltage stored in the capacitor, a power source, and two switches for discretely making and breaking a connection between the photoelectric converter circuit and the magnet driving circuit so that a current is supplied from the power source to the magnet driving circuit only during the shutter operation. A compensation circuit including a resistor is connected with the power source in parallel relationship with the photoelectric converter circuit and the magnet driving circuit. At least one end of the capacitor is connected with the compensation circuit so that the capacitor may be supplied with part of the terminal voltage of the resistor caused by a voltage drop occurring in the power source as it supplies a current to the magnet driving circuit.

Single phase induction motor brake

Abstract: The capacitor in a single phase induction motor is used as a current limiting impedance in a DC braking circuit. The circuit includes the AC source, the capacitor, a rectifier and a field winding.

Exposure value controlling apparatus

Abstract: An electronic exposure controlling apparatus for use in cameras having a capacitor to be charged through a first resistive circuit from a voltage source in association with the depression of a shutter release. A switching circuit effects switching action when the charge of the capacitor comes to a predetermined value. A shutter of a shutter mechanism is opened in response to the switching action of the switching circuit and a switch connects the capacitor to a second resistive circuit, including a photoconductive element, in synchronism with the opening of the shutter so as to discharge the capacitor. The switching circuit actuates the closing of the shutter when the capacitor discharges to a predetermined value.

Varactor tuned coaxial cavity negative resistance diode oscillator

Abstract: A Gunn diode is connected in series with the center conductor of coaxial resonator for exciting the resonator with microwave energy. A first voltage variable capacitor is disposed within the resonator in series with the Gunn diode for tuning thereof. The voltage variable capacitor is carried at the inner end of a choke structure disposed within the hollow interior of a conductive sleeve in DC insulated relation to the sleeve. An inductive wire is parallel resonated with the package capacitance of the series voltage variable capacitor and connects the inner terminal of the voltage variable capacitor to the sleeve of the choke for applying a variable bias voltage to the voltage variable capacitor for tuning the resonator. A similar second voltage variable capacitor and choked sleeve support is connectable for shunt tuning of the Gunn diode.

Time delay after de-energization circuit

Abstract: A timer circuit, adapted to provide a preselected time interval after loss of power to it to control reapplication of power to controlled means if the outage exceeds a predetermined interval, including a direct current power supply, resistor means connected across the power supply, a capacitor connected in circuit relationship with the power supply and resistor means whereby the rate of discharge of the capacitor is controlled by the resistor means, an enhancement mode field effect transistor connected in circuit relationship with the capacitor and a voltage level detector means such as to provide a linear output to the voltage level detector means corresponding to the charge existing on the capacitor, and wherein in accordance with one form of the invention the enhancement mode field effect transistor comprises a metal oxide semiconductor field effect transistor and the voltage level detector means comprises a Schmitt trigger circuit consisting of first and second transistors connected in circuit relationship with their associated resistors.

Circuit for providing precise time delay

Abstract: Integrated circuit structure responsive to being triggered to produce output signals at precise time intervals following points in the operation of a device. The circuit is adapted for accurate repeating operation, and provides a plurality of signals at different precise time delays. A discrete capacitor is discharged to a predetermined value (reset) by a voltage regulator at each triggering of the circuit, and at the end of a short time starts to charge so that the voltage thereacross forms a repeatable exponential ramp. A plurality of comparators are coupled to the capacitor and each produces an output when the capacitor voltage reaches the reference voltage for that comparator. The triggering may be provided by a circuit including a reset capacitor which responds to the change of levels of a signal derived from the device to alternately charge and discharge the reset capacitor. The voltage across the reset capacitor is applied to a pair of comparators which produce current pulses during the beginning of the charge and discharge periods of the reset capacitor for operating the voltage regulator.

Frequency-to-voltage converter device

Abstract: A frequency-to-voltage converter for use with such devices as magnetic tape handling equipment is provided having a frequency error signal generator providing pulses, a constant current generator, a capacitor and two switches controlled by the pulses. One of the switches discharges the capacitor within a fixed time interval and the other switch connects the capacitor to the current generator for a time interval determined by the pulses. The capacitor is thus charged to reach a voltage of the next pulse, thereby providing a voltage across the capacitor terminals which is a continuous voltage error signal suitable for control purposes.

Electronic flash unit having protective circuit for flash terminating switch

Abstract: A semi-conductor switch interrupts the flashtube current, thereby terminating the flash when a blocking voltage is applied to its anode. The blocking voltage is derived from a capacitor. If the capacitor has not sufficiently recharged following a previous flash, the semi-conductor switch is not completely blocked causing it to burn out. Therefore, a transistor is provided whose emitter-collector circuit short-circuits the ignition capacitor when conductive. The base of the transistor is connected to the charging circuit for the capacitor furnishing the blocking voltage in such a manner that the transistor remains conductive until the capacitor charging current has decreased to a predetermined current.

Constant lock-in range automatic frequency control

Abstract: In a voltage variable capacitor tuned superheterodyne receiver, the manual tuning voltage and the automatic frequency control voltage are ordinarily applied to separate voltage variable capacitor diodes connected to the local oscillator tuned circuit Constant automatic frequency control lock-in range over the tuning band is achieved by applying a small fraction of the automatic frequency control voltage to the manual tuning capacitor

Capacitor fired thyristor

Abstract: A capacitor is discharged through the control circuit of a thyristor to positively render the thyristor conductive.

Lighter with a capacity discharge ignition system and means for preventing automatic recharging of said capacitor

Abstract: A smoker''s lighter having a capacitor discharge electric ignition in which the recharging of the capacitor is prevented by means of a two transistor semiconductor switch. Reactuation of a manual ignition switch is necessary before the capacitor can be recharged. Automatic discharge of the capacitor is achieved by use of a trigger diode controlling a thyristor.

Voltage adaptor circuit

Abstract: An electrical circuit for automatically adapting an inductive load to that of one of two possible A.C. supply voltages applied across the circuit. The circuit comprises a capacitor connected in series with the load. The capacitor value is such that a series resonant circuit is formed with the load at a frequency of operation. A controlled semiconductor device having a pair of terminals and a gate terminal is connected with the pair of terminals in parallel across the capacitor. The gate terminal is connected through a non-linear current-voltage characteristic electrical component to one of the terminals of the A.C. supply voltage. For the lower A.C. supply voltage, the capacitor and inductor form a series resonant circuit and at the higher A.C. supply voltage, the controlled semiconductor device short circuits the capacitor.

Asymmetry protection arrangement for series-connected capacitor units

Abstract: Capacitors operable at high voltages consist of series-connected capacitor units, each of which is in turn composed of capacitors which are connected parallel to each other and can be individually disconnected by fuses. An asymmetry protection arrangement is disclosed for monitoring these units for voltage asymmetries. The arrangement compares the sum of the voltage drops present at the individual capacitor units with the voltage drop of the individual capacitor units to provide a signal in response to a fault condition. The signal thus obtained is usable for initiating a turn-off operation or for indicating a fault condition.

Method and apparatus for generating timing pulses with varying distances

Abstract: A timing pulse generator producing periodic pulse sequences with the distances between successive pulses in each sequence varying according to a periodically varying voltage employed as the upper voltage limit to which a charging capacitor is charged. A bistable switch is responsive to the charging capacitor reaching the upper voltage limit to effect both a change in level in its output voltage and discharge of the capacitor to a lower voltage limit. Upon the charging capacitor reaching the lower voltage limit the bistable switch is again responsive to effect both a change in level in its output voltage back to its original level and the charging of the capacitor.

Earth leakage detector for operating circuit interrupting means

Abstract: A device for detecting the occurrence of an earth leak fault in a circuit the live and neutral conductors of which constitute first and second primary windings of a core-balance transformer or toroid. On the occurrence of an earth leak fault, a voltage is induced into a secondary winding on the toroid. The secondary voltage is rectified and the rectified voltage charges first and second capacitors. The second capacitor is charges to a lower voltage than the first capacitor. When the first capacitor is fully charged a first switching device is energised. This, in turn, causes a second switching device to be energised allowing the second capacitor to discharge into and operate a circuit breaker or the like. By using two capacitors in the manner described above the toroid is operated in a more efficient manner than has hitherto been possible.

Rate of change of velocity control system

Abstract: A skid control system for a wheeled vehicle having braking apparatus. By the system, wheel speed is monitored and converted to module input signals having a time spacing corresponding to the velocity of the wheel. These signals are used to control the charge and discharge of a velocity generator capacitor and a velocity reference generator capacitor. Between input signals a controller will cause the velocity generator capacitor to be charged from a certain threshold value to a peak value corresponding to the instantaneous velocity of the wheel and the velocity reference generator capacitor to be charged from the peak value of the velocity generator capacitor at a rate and to a voltage level corresponding to a desired deceleration rate. Upon the termination of input signal the controller will reset the velocity reference generator capacitor to the peak value of the velocity generator capacitor and the velocity generator capacitor to its threshold value. The voltage levels of the capacitors are compared by an operational amplifier and if the velocity reference generator capacitor has the lower voltage level, which indicates an impending wheel lock condition, an output is developed which through an output signal generator will operate the braking apparatus to relieve the braking force. The system is prevented from operating when the vehicle is stationary and also incorporates provisions for preventing response to minor velocity fluctuations and to wheel velocities below a certain minimum.

Counter circuit using current source

Abstract: An integrated counter circuit includes a charge storage capacitor having a charging path connected in series with an interrupted current source which is rendered alternately conductive and nonconductive by the input signal pulses or cycles which are to be counted by the circuit. The charge on the capacitor is applied to one input of a regenerative threshold switch which is supplied with a reference potential to establish the switching level. When the charge on the capacitor becomes sufficiently high enough the regenerative switch is rendered conductive and rapidly discharges the capacitor. To enhance the sharpness of the switching point of the regenerative switch, an attenuated input signal at the frequency used to switch the current source is applied to one of the inputs of the regenerative switch.

Varactor tuning system having means to maintain terminal voltage of varactor biasing capacitor within desired range

Abstract: A tuning system in which a tuning voltage is applied from a voltage holding circuit including a capacitor to a tuning circuit using a variable capacitance diode When the terminal voltage across the capacitor is reduced, the capacitor is charged from a power supply through a switch to compensate the reduction When the frequency of the tuning circuit is changed to a predetermined extent, the switch is closed to recover the initial level of the voltage of the voltage holding circuit

Projection type duplicator

Abstract: In a projection type duplicating apparatus the lighting energy of the light source is controlled in accordance with the magnification of the projecting lens system by a number of control circuits and a control switch is actuated by the proper positioning of the photosensitive means within the image receiving position. The circuit for controlling the energy of the light source includes a capacitor connected in series with the control switch and a relay actuated by the discharge of that capacitor for energizing the light source. In an alternative embodiment the control circuits each comprise a portion of the primary winding of a transformer, the secondary winding of the transformer being connected across an additional capacitor whereby the charging voltage of the additional capacitor is controlled by the transformer.

Solid-state switching capacitor

Abstract: A capacitor structure comprising a first thin film tunneling capacitor in circuit with a resistor and a second capacitor wherein the capacitance value of said structure switches abruptly with applied bias potential.

Reactance measurement apparatus

Abstract: Disclosed is an apparatus for measuring the energy storage characteristics of passive electrical components such as capacitors and inductors. In a capacitative embodiment an a.c. signal alternately charges and discharges a capacitor under test and a second a.c. signal similarly charges and discharges a standard reference capacitor. An indicator that displays current flow is alternately connected to the capacitors by a switch that is synchronized to the a.c. signals. The relative amplitudes of the a.c. signals are adjusted so that each capacitor absorbs an equal charge and the indicator is responsive to this condition and displays a null indication. A capacitance change in either capacitor causes a departure from the null condition. A preferred embodiment is disclosed in which the capacitor under test is a variable capacitance transducer. Inductance measurements are made with a similar inductance circuit.

High voltage measuring apparatus

Abstract: A high voltage circuit is established including a resistor and a variable capacitor adapted for connection in series with an unknown high voltage D.C. source. The capacitance of the variable capacitor is varied by a speaker excited by an A.C. source. A D.C. blocking capacitor is connected from the junction of the variable capacitor and the resistor. The A.C. voltage across the resistor or the variable capacitor is then impressed through the D.C. blocking capacitor on an A.C. voltage measuring or indicating circuit which may include a synchronous detector connected from the A.C. source, and a D.C. voltmeter connected from the synchronous detector and calibrated to read in the voltage of the D.C. source.