Showing papers on "Decoupling capacitor published in 1974"

Capacitor discharge ignition system with controlled spark duration

Abstract: A capacitor discharge ignition system for a spark-ignition internal combustion engine. The ignition system includes an ignition coil having first and second primary windings, a secondary winding and a ferromagnetic core about which the windings are wound. A spark plug has electrodes which are spaced apart to form a spark gap which is connected in series with a first capacitor. The series-connected spark gap and first capacitor are connected across the secondary winding. A second capacitor is coupled to the first winding and a DC source of electrical energy is provided. First circuit means charge the second capacitor from the DC source and discharge this capacitor through the first primary winding in timed relation to operation of the engine. Second circuit means are provided for producing a fixed frequency oscillatory current in the second primary winding for a predetermined time interval subsequent to each discharge of the second capacitor through the first primary winding. The discharge of the second capacitor through the first primary winding and the subsequent supply of fixed frequency oscillatory current to the second primary winding causes ferroresonant oscillations in the secondary circuit of the ignition coil for at least a portion of the aforementioned predetermined time interval. The spark which occurs between the spark plug electrodes exists during the predetermined time interval and has a duration which may be varied as desired.

Distance relay performance as affected by capacitor voltage transformers

Abstract: A 3-phase capacitor-voltage-transformer simulation is described which, when used in conjunction with a conventional artificial transmission line, allows complete relaying schemes to be tested. The accuracy of the simulation is confirmed by comparison of its response with that of a full-scale capacitor voltage transformer. Conjunctive distance-relay/capacitor-voltage-transformer tests are reported showing that transient errors degrade relay performance in speed and stability. Various methods for providing a more faithful voltage signal to supply the relay circuits are discussed.

Reversible analog/digital (digital/analog) converter

Abstract: A converter for providing an analog output signal corresponding to a digital input signal, or for providing a digital output signal corresponding to an analog input signal. The converter includes a serial digital to analog switching circuit and a voltage comparator. The comparator output is connected to a digital number storage means which is connected to control means for controlling the digital to analog switching circuit. A digital number stored in the digital storage means is transfered to the control means. The digital to analog switching circuit contains a pair of matched capacitors having one plate connected to ground potential. A first switching means is actuated by the control means to discharge the first capacitor if the least significant bit in the digital number is a zero and to charge the first capacitor to a reference voltage if the least significant bit in the digital number is one. The control means actuates a second switch to discharge the second capacitor. The charge on the first capacitor is shared with the second capacitor through a charge sharing switch thereby providing a voltage on both capacitors corresponding to the digital bit. The sequence of operating the first switching means and charge sharing switching means is repeated to produce a voltage on both capacitors corresponding to the digital number. The voltage on either capacitor may be connected to one input of the voltage comparator and an unknown analog voltage may be connected to another input of the voltage comparator. In the instance where the second capacitor is connected to the comparator an output is produced therefrom having a predetermined voltage level for the condition when the unknown analog voltage exceeds the voltage on the second capacitor and having zero output when the unknown analog voltage is less than the voltage on the second capacitor. The output of the voltage comparator is connected to the storage means for the digital number, so that the digital number is stored sequentially from the most significant bit to the least significant bit. The control means provides for shifting and latching the digital number in the storage means.

Temperature compensated combined current and voltage measuring apparatus

Abstract: The combined current and voltage measuring apparatus has a cast resin body which supports the current measuring unit. The voltage measuring unit includes a capacitive voltage divider with an amplifier connected thereto. The cast resin body is also utilized as dielectric for the capacitor on the high-voltage side of the capacitive voltage divider. Embedded in the cast resin body is an auxiliary capacitor with a dielectric which, with respect to temperature dependence, corresponds to the dielectric of the high-voltage capacitor. The auxiliary capacitor, in series with a resistor, is connected to an auxiliary generator. The voltage dropped across the resistor is supplied, after rectification, to an input of a differential amplifier; the other input of the differential amplifier is connected to the terminal away from ground of the capacitor on the low-voltage side of the capacitive voltage divider. With respect to the capacitors of the capacitive voltage divider, a warming of the capacitor on the high-voltage side different from the warming of the capacitor on the low-voltage side does not influence the measuring accuracy of the capacitive voltage measuring unit of the apparatus.

Circuit arrangements in telephone apparatus

Abstract: A pushbutton telephone semiconductor dialling circuit power supply comprising a capacitor fed by a diode bridge placed in series with the line looping circuit during dialling. The capacitor size is chosen to charge to at least minimum circuit supply voltage during make periods of line looping, and to keep the circuit supplied during break periods. A constant current charging circuit may be employed to charge the capacitor from the bridge to improve performance, with a diode to power the circuit directly from the bridge while the capacitor is still charging. The microphone-bridging off-normal contacts may be replaced by a transistor switching circuit.

Circuit for supplying a dc load from an ac source through a rectifier

Abstract: An improvement A.C. a circuit for supplying a D.C. load from an A.C. source through an uncontrolled rectifier with a control element arranged between the output of the rectifier and D.C. load using a control unit synchronized with the A.D. source to keep the power factor at a predetermined value and the circuit including a capacitor associated with the DC control element and a by-pass diode bridged across the DC load in which, in order to suppress harmonics to the greatest degree possible, the DC load is bridged by two by-pass diodes connected in series in the same direction and the capacitor associated with the DC control element is connected between one input terminal and the center connection point of the two by-pass diodes. In a second variation, the same result is achieved with the capacitor and a first decoupling diode connected in series between the input terminals of the DC control element with one electrode of the capacitor connected with one input terminal of the DC control element and the other electrode of the capacitor through a second decoupling diode to an output terminal of the DC control element.

Capacitance multiplier circuit

Abstract: A capacitance multiplier circuit having first and second terminals adapted for use in integrated circuits. An NPN transistor has its emitter connected to the second terminal, its base connected to one electrode of a capacitor and its collector connected to the other electrode of the capacitor and also to the first terminal. Increasing the voltage of the first terminal causes a charging current to flow in the capacitor and into the base of the transistor. The capacitor charging current is multiplied by the current gain of the transistor. The apparent capacitance between the first and second terminals is equal to the capacitance of the capacitor multiplied by the current gain of the transistor.

Fault-current limiter for high power electrical transmission systems

Abstract: A fault-current limiter is formed as a self-contained unit which can be connected in an existing power transmission system. The fault-current limiter consists of a series-connected inductor and capacitor which are resonant with the power line frequency, and a normally open switch is in parallel with the capacitor. A sodium fuse connected in series with a calibrating impedance is connected in parallel with the switch and the fuse is operated under predetermined circuit current conditions. The sodium fuse extends an operating plunger upon its operation, and the plunger causes the switch to close, thereby to short-circuit the capacitor and connect the current-limiting impedance of the inductor in the main power circuit.

Circuit for soft-starting electric load comprising temperature sensitive diac

Abstract: A circuit for triggering a bidirectional thyristor having a capacitor charged from an ac source includes a semiconductor thermally sensitive switch having a break-over voltage dependent upon a temperature and applied with a voltage across the capacitor. Upon the closure of an ON-OFF switch, the capacitor voltage reaches the break-over voltage to break the semiconductor switch over to turn the thyristor on at a large firing angle resulting in a current flowing through a load. Then the semiconductor switch is heated by a heating resistor connected across the load to decrease in the break-over voltage to decrease the firing angle of the thyristor until a steady-state current flows through the load.

Spark ignition circuit for gas burners

Abstract: In a spark igniter circuit for gas burners operable on a low voltage direct current supply, a transistor is alternately driven to saturation and cut off abruptly so as to produce, through inductive coupling, high voltage pulses at relatively high frequency to incrementally charge a storage capacitor; a SCR is gated when the storage capacitor attains a predetermined charge and permits the discharge of the capacitor through the primary winding of an ignition transformer, thereby to produce strong sparking across spaced electrodes in a secondary circuit at relatively low frequency; and the spaced electrodes are arranged to be bridged by burner flame and the SCR gating signal is shunted across the spark electrodes to cut off discharge of the capacitor and sparking when burner flame bridges the spark gap.

Discharge lamp control circuit

Abstract: A voltage producing device comprises a circuit in which an AC power source, a coil and a first capacitor connected in series. A unidirectional triode semiconductor switching element is connected across both terminals of the capacitor, a voltage limiting semiconductor element is connected to a gate electrode of the switching element, and a charging-and-discharging circuit including a second capacitor is connected to a cathode of the switching element.

Capacitor structure and circuit facilitating increased frequency stability of integrated circuits

Abstract: A stabilizing circuit which increases the effective value of a capacitor and the structure of a monolithic capacitor are disclosed. The stabilizing circuit includes a transistor having a base electrode connected to the capacitor and an emitter electrode connected to a point at which it is desired to provide an increased effective capacitance. The capacitor structure is suitable for being included in monolithic integrated circuits having diffused isolation regions. A first plate of the capacitor is formed by a metallization layer, the second plate of the capacitor may be formed by an emitter diffusion into the isolation diffusion. A base diffusion which is conductively connected to the emitter diffusion and to the isolation diffusion facilitates connection of the second plate of the capacitor to the substrate.

Capacitor bank protection relay

Abstract: A protective relay for shunt capacitor banks which is arranged to provide a neutralizing signal which balances any initial unbalance inherent in the capacitor bank which may be due to slight differences in the capacitors which make up the bank so that initially the output signal is substantially zero whereby the sensitivity of the relay to the failure of one or more of the parallel series connected capacitors is considerably increased without the necessity of amplification or other complications. The relay further is rendered insensitive to varying unbalances present in the polyphase transmission line, not caused by capacitor failure, by the use of resistive elements connected to compensate for line unbalance. These resistors will be more secure against failure than the capacitor elements used in the shunt capacitor banks.

Pneumatic and hydraulic control valves

Abstract: In order to provide intrinsically safe operation of an electromagnetically operated device, such as a pneumatic or hydraulic valve, a circuit in accordance with the invention includes electrical energy storage means, such as a capacitor, which is charged from a source at an intrinsically safe energy level and is subsequently at least partially discharged via switching means through an operating coil of the electromagnetic device. The capacitor is preferably charged from an intrinsically safe d.c. supply via a diode which inhibits discharging of the capacitor back into the d.c. supply. The switching means preferably operates to connect the capacitor to the operating coil when the charge on the capacitor reaches a predetermined level, as determined by a voltage sensitive device which responds to the capacitor voltage. The circuit may be used to operate a valve of the latching type having two operating coils connected in series, the capacitor being discharged through both of said coils to set the valve, the circuit including a second storage means connected in series with the coils and means for discharging the second storage means through one of the coils to reset the valve. The second storage means may be charged from the first storage means in a succession of steps.

Piezoelectric bimorph controlled variable capacitor

Abstract: This invention relates to a remotely controlled variable capacitor, more ticularly, to an electromechanical capacitor with one of the capacitor electrodes mounted on one surface of a bimorph element and the other capacitor electrode mounted on the surface of a superimposed bimorph element. In response to a DC electrical signal, there is a mechanical motion separating the capacitor electrodes to vary the capacitance therebetween.

Pulse generator for electro-erosion machining apparatus

Abstract: A pulse generator for an electro-erosion machining apparatus wherein electrical discharges occur at a machining zone formed between an electrode workpiece and an electrode tool, the pulse generator comprising a capacitor charged from a source of direct current through an inductance and a switch for discharging the capacitor through the primary of a transformer, the electrode tool and the workpiece being connected across the secondary of the transformer, the capacitor being charged at a predetermined current rate and being discharged when the voltage across the capacitor reaches a preset level.

Rate signal generator circuit

Abstract: Disclosed herein is circuitry for producing a signal proportional to the rate of recurrence of a periodic input signal applied to the circuitry. When an input pulse is received a timing circuit is energized to charge a capacitor to a predetermined level. The capacitor is then discharged through a resistance circuit having resistance portions which are electronically switched in and out of the circuit so that the discharge, rate of the capacitor defines the desired rate function. Then, upon commencement of a subsequent pulse a sample and hold circuit is actuated to sample the discharge level of the capacitor to provide an accurate indication of the pulse rate.

Voltage regulator circuit with relatively low power consumption

Abstract: A circuit for regulating the voltage across a capacitor which is charged by a pulse driven voltage converter. In the present circuit the voltage across the capacitor is sampled during each pulse period. The width of the pulse employed to drive the converter is then adjusted in response to this voltage to the lowest value required to replace the charge lost by the capacitor since the preceding pulse.

Power supply circuit with electro-magnetic feedback

Abstract: The embodiment of the invention disclosed herein is directed to a power supply circuit for providing operating voltage to electric utilization means. The power supply includes an oscillator circuit which has a transistor connected in series with the primary winding of a coupling transformer, which primary winding functions as the inductance element of a resonant tank circuit. A capacitor is connected in parallel with the inductance element and recirculating current flows therebetween. An electromagnetic feedback element is coupled to the leads of either the capacitor or inductance element to sense the recirculating currents within the tank circuit formed thereby. Heavy load conditions at the output of the power supply will cause a decrease in the recirculating currents thereby reducing the feedback for the oscillator which, in turn, will reduce the output of the power supply.

Voltage transformer for a completely insulated high-voltage installation

Abstract: A voltage transformer for a fully-insulated, high-voltage installation with a grounded metal encapsulation includes one electrode arranged in a support insulator which holds the high-voltage conductor centrally in the metal encapsulation. The electrode of the support insulator represents the low-voltage electrode of a high-potential capacitor conjointly defined by this electrode and the high-voltage conductor of the high-voltage installation. The high-potential capacitor and a low-potential capacitor conjointly define a capacitive voltage divider. An amplifier is connected to the low-potential capacitor of the voltage divider.

Method and system for determining the resistance of the dielectric in a capacitor

Abstract: A rapid and accurate indication of the resistance of the dielectric in a capacitor with respect to a minimum acceptable value is obtained by connecting the capacitor in a feedback circuit of a high gain amplifier between an output and an input thereof. Initially, the capacitor is rapidly charged through a variable resistance connected to the input of the amplifier, until the charge on the capacitor is equal to a set value, such as its rated voltage. The variable resistance then is abruptly increased to a predetermined value that will maintain the charge on an acceptable capacitor at the set charge value. The voltage output of the amplifier then is monitored to ascertain stability, further charging or discharging of the capacitor, to provide an indication as to whether the capacitor''s dielectric resistance is at, above or below the minimum acceptable value, respectively.

Method and system for sensing charges at distributed points on a charge coupled device

Abstract: The specification discloses a technique for non-destructively sampling the charge stored adjacent distributed phase electrodes in a charge coupled device. A storage capacitor is provided with a capacitance in the range of the combined capacitance of the phase electrodes. A first switch is operable during a first clock period for connecting the capacitor to a source of reference voltage. A second switch is operable during the first clock period for connecting the phase electrodes to be sampled to circuit ground. An insulated gate field effect transistor is connected with its source and drain between the phase electrodes and the second switch. The gate of the transistor is biased at a voltage level less than the reference voltage. The first and second switches are then operable during a second clock period for coupling the charged capacitor through the field effect transistor to apply clock voltage to the phase electrodes, wherein the capacitor discharges by an amount proportional to the charge stored adjacent the phase electrodes. An output circuit is connected to the capacitor for detecting the amount of discharge of the capacitor to indirectly sample the charge.

Bipolar transistor memory with capacitive storage

Abstract: The memory is formed of an array of cells, each of which is coupled to the word and bit lines. Each cell comprises only a bipolar transistor coupled to a capacitor. The base terminal of the transistor is connected directly to the word line and either the emitter terminal or the collector terminal of the transistor may be coupled in series with the capacitor. In one embodiment the transistor, in series with the capacitor, is connected between a bit/sense line and a reference voltage and in another embodiment between the bit line and a sense line. Information is stored in the capacitor by discharing the capacitor through the transistor and information is read out by charging the capacitor. During a read/erase operation the word line, which is normally at a quiescent voltage, is raised to a higher voltage to render the transistor conductive between its collector and emitter. Simultaneously, the bit line has impressed upon it a positive voltage. During a write operation the word line has impressed upon it a voltage which is between its quiescent voltage and its read/erase voltage. If a 0 is to be stored, the bit line is maintained at a high level and the capacitor charged. If a 1 is to be stored, the voltage on the bit line is substantially reduced so that the capacitor is discharged. During the read operations a signal is transmitted to the bit line if a 1 has been stored previously.

Power factor correcting means

Abstract: A power factor correcting means for connection to an AC voltage network includes a transformer with high voltage terminals for connection to the network and low voltage terminals. A capacitor battery is provided for connection to the network, and a controllable inductive element is connected to the low voltage terminal of the transformer. The capacitor battery includes a first part connected to the high voltage terminal of the transformer, and a second part connected to the low voltage terminal of the transformer. The total rated power of the capacitor battery is substantially as great as the maximum reactive power of the inductive element, and the rated power of the second portion of the capacitor battery is between 0.3 and 0.7 times as the maximum reactive power of the inductive element.

Voltage maintenance apparatus

Abstract: A capacitor in parallel with a CMOS memory is used, in the event of a power outage, to apply a sufficient temporary voltage to the memory to maintain the stored data. Data storage retention time is maximized by a resistor, connected between the capacitor and the memory, having a resistance R approximately given by R = 0.4 (V.sub.i - V.sub.f)/I.sub.f (1) where V i is the initial voltage on the capacitor, V f is the minimum voltage for maintaining the data and I f is the capacitor discharge current at voltage V f .

Pulse peak detector

Abstract: A pulse peak detector for generating a DC signal proportional to the peak amplitude of applied short duration input pulses of a repetitive train, includes a signal input circuit to which the pulses are applied, a first storage capacitor, a differential comparator connected to the input circuit and to the pulse storage capacitor for producing a saturation output signal having a time duration equal to the time during which the input pulse exceeds the amplitude of the level stored on the capacitor. The output pulse thus generated is coupled to an error amplifier and a second storage capacitor at the output of that amplifier, the second capacitor being DC coupled to the first. The time constants of the capacitors and their associated resistive charging circuits are selected so that the coupling circuit and the second storage capacitor has a time constant which is long relative to the repetition rate of the applied signals. The first storage capacitor and its charging circuit has a significantly shorter time constant so that the second capacitor tends to replenish the charge on the first and also produces a DC output level which is representative of the peak amplitude of applied input signals.

Electric vehicle power circuit

Abstract: A power circuit for dc-to-dc pulse control or chopper systems. A pair of unidirectional conduction devices are each connected to a common end of a capacitor placed across a DC load, while a main thyristor is used to couple the load to a source of dc potential. A first one of the unidirectional conduction devices allows current to flow to the capacitor through a path including an inductance. The inductance induces an overcharge upon the capacitor which is subsequently applied to the main thyristor by way of the second unidirectional conduction device to procure the commutation of the main thyristor.

Voltage transformer for completely insulated, metal-clad high-voltage installations

Abstract: A voltage transformer for a completely insulated, metal-clad, high-voltage installation includes an electrode of extended surface area which is arranged inside the metal outer tube of the high-voltage installation. This electrode and the high-voltage conductor of the installation conjointly define the highpotential capacitor of a capacitive voltage divider. The dielectric of the high-potential capacitor is an insulating member which carries the extended-area electrode. The insulating member carries, in addition, the low-potential capacitor of the capacitive voltage divider. An amplifier, followed by a load, is connected to the low-potential capacitor.

Capacitor discharge ignition system with overspeed control

Abstract: Disclosed herein is a capacitor discharge ignition circuit with engine overspeed control comprising an engine ignition subcircuit electrically connected to a capacitor and including a primary winding and a normal nonconductive electronic ignition switch connected in series with the primary winding and including a trigger element operative to close the ignition switch ahd thereby to discharge the capacitor through the ignition subcircuit to effect spark production, together with a speed control sub-circuit connected to the capacitor in parallel with the ignition sub-circuit and including resistor means and a normally nonconductive electronic speed control switch connected in series with the resistor means and including a control element operative to close the speed control switch and thereby to discharge the capacitor through the speed control sub-circuit during a time interval determined by the resistor means and independent of engine rotation, and coil and magnet means rotatable relative to each other in accordance with engine speed and electrically connected to the capacitor, to the control element, and to the trigger element for sequentially charging the capacitor with a speed control charge, generating a speed control pulse and applying the speed control pulse to the control element, charging the capacitor with an ignition charge, and generating a trigger pulse and applying the trigger pulse to the trigger element.

Ignition-control system for internal-combustion engine

Abstract: In order to vary the timing of the ignition of an air/fuel mixture in a cylinder of an internal-combustion engine as a function of engine speed, a flip-flop is set by an engine-controlled switch at a predetermined point t 0 in the cycle, in a position preceding by an angle α 0 the upper-dead-center position of an associated piston, to effect a rapid discharge and to start a slow recharge, at constant rate, of a capacitor C 1 forming part of a time/voltage converter. The maximum voltage attained by this capacitor at the end of a cycle, as a measure of cycle length T, is registered in an ancillary capacitor C 3 as another capacitor C 2 , forming part of a voltage/time converter, also begins charging at time t 0 at a rate making the charges of capacitors C 2 and C 3 equal on or before the attainment of the UDC position. This equality is detected by a comparator which thereupon, at a time t 0 +t.sub.γ, resets the flip-flop to trigger an igniter for the associated cylinder. The charging rate of capacitor C 2 may be modified by one or more sensing circuits responsive to external parameters and/or by one or more threshold circuits upon the charge of capacitor C 1 or C 2 reaching a predetermined level. Capacitors C 2 and C 3 are discharged upon the resetting of the flip-flop, the recharging of capacitor C 3 beginning shortly thereafter.