Showing papers on "Filter capacitor published in 1982"

Boost power supply having power factor correction circuit

Abstract: A boost power supply having a full-wave rectifier driving an inductor, diode, and the parallel combination of a filter capacitor and load. A shunting switch connected between the inductor and diode is periodically closed to draw current through the inductor, thereby charging the inductor. The switch is then opened so that the inductor, while discharging, generates a relatively high voltage which is applied to the load and filter capacitor through the diode. The shunting switch is opened and closed in a manner which causes the input current to follow a sinusoidal waveform in phase with the input voltage with an amplitude that maintains the output voltage of the power supply constant. Specifically, a harmonically pure sinusoidal waveform is multiplied by a voltage inversely proportional to the output voltage. An offset is then added and subtracted to this waveform to generate respective positive and negative reference waveforms which are both in phase with the input voltage but differ slightly in magnitude from each other. A signal indicative of the input current is compared to the positive and negative reference waveforms to open the shunting switch when the input current reaches the level of the positive reference waveform and to close the shunting switch when the input current falls to the level of the negative reference waveform. In order to maintain the operating frequency of the switch constant, the difference between the positive and negative reference waveforms may be varied throughout the sinusoidal cycle so that the time for the inductor to charge to the positive reference waveform and discharge to the negative reference waveform is constant.

Integration of analog filters in a bipolar process

Abstract: Monolithic analog filters are described which are based on the integration of electronic transconductors and capacitors. The method used allows simulation of inductor capacitor filters. The transconductors are voltage-controlled current sources provided with a scaling multiplier. The value of one external resistor and matching of integrated elements determine the transconductances. Capacitors are made with an oxide/nitride dielectric on the low-ohmic emitter diffusion and with an aluminium top electrode. Applications include PCM low-pass filters, viewdata modem filters, etc. The method is extendable from the audio band up to video frequencies. Simple breadboarding, no need for special CAD, and an extremely low supply power consumption are features of the filter type. The filters are on-chip compatible with analog and digital system parts.

Electronic ballast for a discharge lamp

Abstract: An electronic ballast for a discharge lamp (8) for restricting and stabilizing the lamps current. The ballast comprises a high frequency oscillator for connection to a D.C. supply which consists of two transistors (1,2) connected in series, with a base drive transformer (3) coupled between them to bring the transistors (1,2) into alternating phase operation. A resonance circuit connected in series with the primary winding (4) of the transformer (3), comprises an inductor (7), resonance capacitors (10 and 11) and a capacitor (9) coupled in parallel with the lamp (8). The lamp (8) is, in turn, connected in series with the resonance circuit. In addition, a filter capacitor (c) having a high charging ability is coupled between the terminals of the D.C. supply. The resonance capacitors (10 and 11) are connected in series between the terminals of the D.C. supply, and diodes (23, 24) are connected parallel to them, and the last part of the resonance circuit is connected to a point common for the capacitors and the diodes, e.g. by means of the electrode (8a) of the lamp (8).

Switched capacitor DSB modulator/demodulator

Abstract: An integrated single-sideband modulator comprises six integrated capacitors C1-C6 and first switch means alternately connecting C1 and C2 as feedback capacitors across a differential input operational amplifier A1. The amplifier has a virtual ground potential on its inverting input terminal for causing it to operate as a voltage source and render the circuit relatively insensitive to parasitic capacitance effects associated with capacitor plates. Second switch means cooperates with A1, C1 and C2 and is responsive to 4-phase clock signals for driving input capacitors C3-C6 so as to convert first and second quadrature-phase input signal voltages into first and second electrical charge flow signals on the inverting input terminal that are a function of products of representations of the first and second voltages in switch state time intervals and associated pulse trains which have a 90° phase difference therebetween and a repetitive pattern such as +1, +1, -1, -1, etc. The amplifier and feedback capacitors combine the charge signals for producing a single-sideband signal on A1's output terminal. This circuit is converted to a balanced modulator by omitting C5 and C6. In an alternate embodiment of a single sideband modulator that requires only a pair of switched capacitors C11 and C12, a 4-phase switch means alternately charges C11 and C12 with associated ones of the quadrature-phase input signal voltages while alternately connecting C12 and C11 as feedback capacitors across A1, the polarity of each capacitors feedback voltage being reversed each time that capacitor is connected across the amplifier. This circuit is operated as a balanced modulator by omitting one of the capacitors.

Tantalum oxide capacitors for GaAs monolithic integrated circuits

Abstract: The performance of a high-yield tantalum oxide capacitor for use in GaAs monolithic microwave integrated circuits is described. The integral metal-insulator-metal sandwich structure is reactively sputter-deposited at low temperatures, compatible with a photoresist lift-off process, on semi-insulating GaAs substrate. Dielectric constants of 20-25 were achieved in the capacitors fabricated. An initial application of this process as an interstage coupling capacitor for a two-stage preamplifier is given.

Switched-capacitance amplifier, a switched-capacitance filter and a charge-transfer filter comprising an amplifier of this type

Abstract: The switched-capacitance amplifier comprises n capacitors C 11 to C 1n which are periodically switched in parallel and in series, the n parallel-switched capacitors being charged simultaneously by the same voltage V E . An amplified voltage n×V E is obtained between the end terminals A and B of the n series-switched capacitors. Periodic switching of the n capacitors in parallel and in series is performed by means of MOS transistors T 11 to T 1 (2n-1) and T 21 to T 2 (n-1) which operate in the switching mode. The n capacitors and the MOS transistors are integrated on the same semiconductor substrate.

Ac-to-dc converter using polarized input isolation capacitors

Abstract: Current-return diodes around input capacitors permits the use of polarized isolation capacitors in a.c.-to-d.c. power supplies. By providing input diodes, the use of more efficient polarized (d.c.) capacitors can be used as the a.c. isolation element, providing surge limiting protection and larger currents at reduced costs.

Inductance-less up DC-DC convertor

Abstract: A new type of up convertor which does not include inductance is described. Voltage multiplication is achieved by charging the capacitors in parallel and discharging them in series. The circuit includes two groups of switched capacitors which are alternately connected to the source and the load, such that the input charging pulses and output ripple are reduced, compared with a circuit including only one group of switched capacitors. This type of convertor may be applied in high-voltage systems, and because there is no inductance, it can also be included in integrated circuits.

Automatic "S" correction circuit

Abstract: An automatic S correction circuit for a resonant scan deflection circuit comprises a plurality of S-shaping capacitors. The peak voltage and the peak-to-peak voltage across the S capacitors are detected, and the number of effective capacitors is varied to maintain the peak voltage and the peak-to-peak voltage in a predetermined relationship.

Sequential capacitive discharge circuit for flash lamps

Abstract: A method of reliably operating flashlamps with most of the stored energy charged to a voltage below the minimum specified electrode voltage is also disclosed. The flashlamp discharge control method allows reliable operation of the same variable voltage energy storage capacitors with more than a ten-to-one selectable variation of lamp Effective Candella Power for visual signalling. The disclosed dynamic impedance matching method matches the energy storage capacitors to the lamp after the three terminal flashlamp is triggered to its manufacturers' specified "on" state in the conventional fashion. When the lamp's main discharge voltage becomes lower than the voltage of the more principal energy storage capacitors, discharge of those capacitors is begun, usually through a semi-conductor rectifier operated within its integrated limits. The more principal energy storage capacitors may be charged with constant energy rather than at constant voltage, so that, for a constant Effective Candella Power, varying capacitances such as are found in electrolytic capacitors may be used with significant savings in size, weight and cost.

C-2C ladder voltage dividers for application in all-MOS A/D convertors

Abstract: C-2C ladders for A/D conversion (analogous to the conventional R-2R ladders) are reported which use only 22 elementary capacitors for 8-bit conversion and 34 elementary capacitors for 10-bit conversion. The nonlinearity contributed by the parasitic capacitances is within ±0.15 LSB.

Switched capacitor balanced modulator/demodulator

Abstract: An integrated single-sideband modulator comprises six integrated capacitors C1-C6 and first switch means alternately connecting C1 and C2 as feedback capacitors across a differential input operational amplifier A1. The amplifier has a virtual ground potential on its inverting input terminal for causing it to operate as a voltage source and render the circuit relatively insensitive to parasitic capacitance effects associated with capacitor plates. Second switch means cooperates with A1, C1 and C2 and is responsive to 4-phase clock signals for driving input capacitors C3-C6 so as to convert first and second quadrature-phase input signal voltages into first and second electrical charge flow signals on the inverting input terminal that are a function of products of representations of the first and second voltages in switch state time intervals and associated pulse trains which have a 90° phase difference therebetween and a repetitive pattern such as +1, +1, -1, -1, etc. The amplifier and feedback capacitors combine the charge signals for producing a single-sideband signal on A1's output terminal. This circuit is converted to a balanced modulator by omitting C5 and C6. In an alternate embodiment of a single sidebank modulator that requires only a pair of switched capacitors C11 and C12, a 4-phase switch means alternately charges C11 and C12 with associated ones of the quadrature-phase input signal voltages while alternately connecting C12 and C11 as feedback capacitors across A1, the polarity of each capacitor's feedback voltage being reversed each time that capacitor is connected across the amplifier. This circuit is operated as a balanced modulator by omitting one of the capacitors.

Floating node stabilizing circuit for a switched-capacitor circuit and filter

Abstract: A pair of fixed capacitors are connected across a pair of serially coupled switched capacitors, the junction of the fixed capacitors being coupled to the floating node of the switched capacitors. As the polarities of the switched capacitors are switched, the fixed capacitors cause a partial discharge, thereby preventing charge from accumulating on the node.

Protective device for service interruption of voltage type inverter

Abstract: PURPOSE:To operate the inverter without regard to the condition of load by supplying the output voltage of the inverter as the power supply of an inverter control circuit when service interruption while controlling the V/F ratio so that DC stage voltage is made constant when service interruption. CONSTITUTION:A voltage detector 9 detects the DC stage voltage, and supplies output to the PWM inverter control circuit 7 controlling the V/F ratio so that the DC stage voltage is made constant when service interruption. The ratio of transformer of a transformer 10 is selected so that the peak value of the secondary output voltage is made slightly lower than the peak value of a commercial power supply 1. A bridge rectifier 11 is connected to the filter capacitor 64 of the power supply 6' of the inverter control circuit. A service interruption detecting circuit 8' issues a command to the PWM inverter control circuit 7 so as to control the V/F ratio so that the DC stage voltage is made constant when service interruption.

Switched capacitor SSB modulator

Abstract: An integrated single-sideband modulator comprises six integrated capacitors C1-C6 and first switch means alternately connecting C1 and C2 as feedback capacitors across a differential input operational amplifier A1. The amplifier has a virtual ground potential on its inverting input terminal for causing it to operate as a voltage source and render the circuit relatively insensitive to parasitic capacitance effects associated with capacitor plates. Second switch means cooperates with A1, C1 and C2 and is responsive to 4-phase clock signals for driving input capacitors C3-C6 so as to convert first and second quadrature-phase input signal voltages into first and second electrical charge flow signals on the inverting input terminal that are a function of products of representations of the first and second voltages in switch state time intervals and associated pulse trains which have a 90° phase difference therebetween and a repetitive pattern such as +1, +1, -1, -1, etc. The amplifier and feedback capacitors combine the charge signals for producing a single-sideband signal on A1's output terminal. This circuit is converted to a balanced modulator by omitting C5 and C6. In an alternate embodiment of a single sideband modulator that requires only a pair of switched capacitors C11 and C12, a 4-phase switch means alternately charges C11 and C12 with associated ones of the quadrature-phase input signal voltages while alternately connecting C12 and C11 as feedback capacitors across A1, the polarity of each capacitors feedback voltage being reversed each time that capacitor is connected across the amplifier. This circuit is operated as a balanced modulator by omitting one of the capacitors.

Control device for electric motor driven vehicles

Abstract: PURPOSE:To prevent the production of an overvoltage at the time of reclosing in an electric motor vehicle by inserting a resistor in a main circuit filter when a main circuit is opened. CONSTITUTION:A breaker 2 is closed in the state that a resistor 7 is inserted to a main circuit filter at the starting time of an electric motor vehicle to suppress the resonance. A breaker 3 is closed after a main filter capacitor 6 is sufficiently charged, and the resistor 7 is shortcircuited. When the main circuit is interrupted, the breaker 2 is first opened, and the breaker 4 is then opened to prevent the overvoltage. When the breaker 2 is opened, the breaker 3 is always opened. In this manner, the resistor 7 is always closed when the main circuit is opened. Accordingly, it can prevent the production of an overvoltage due to the resonance of a main filter reactor 5 with the main filter capacitor 6 at the closing time.

Measuring the Self-Resonant Frequency of Capacitors

Abstract: Methods of measuring the self-resonant frequency of capacitors are presented. Precautions and faults of the various techniques are discussed. The difficulty of measuring the self-resonant frequency (SRF) of a capacitor is greater than might be suspected. Of the several plausible techniques, none is without deficiencies.

Hi-C isolation of DRAM storage capacitors

Abstract: A new method of isolating adjacent DRAM capacitors is presented and characterized. This method increases the capacitor area available for charge storage by 39% over conventional semi-recessed field isolation. Hi-C isolation has been used to make high performance 64K DRAM's which exhibit acceptable refresh properties up to 125°C.

Electric brake device for electric rolling stock

Abstract: PURPOSE:To enable to rise a regenerative current rapidly when a regenerative load at a trolley wire side is recovered and a pantograph isolation is recovered by varying the control of the regenerative current by the compared result of the voltage of a filter capacitor with each set value. CONSTITUTION:A regenerative current limiter 20 operates a regenerative chopper 8 to suppress the current of a motor 2 when the voltage VC of a filter capacitor exceeds a set value V1, and when the voltage VC reaches the set value V2, the limiter generates the maximum limiting output. A comparator 21 operates a resistance chopper 5 when the voltage VC reaches V3(V3>=V2) and resets the chopper to OFF state when the voltage VC becomes lower than V0(V0

Gto inverter device

Abstract: PURPOSE:To contrive to reduce inductance of wiring, and to form snubber resistors and capacitors of a GTO inverter device in small types by a method wherein filter capacitors and GTO's of the GTO inverter device to be connected to an electric power source are accommodated in the same box. CONSTITUTION:The GTO inverter device is constituted of the GTO's 2, flywheel diodes 3, and diodes 4, the capacitors 5, the resistors 6 for snubbers, and the device is connected to the electric power source through the filter capacitor 1 to supply a three phase alternating current to an electric motor 9. At this time, the GTO inverters 11-13 of the respective phases are accommodated in the inverter box 20, while the filter capacitor 1 is divided to be arranged between them. Accordingly because inductance of wiring can be made extremely small shortening wiring length between the GTO's and the capacitor 1, reduction of heat quantity to be generated and formation of the apparatus on the whole in the small type can be attained reducing capacities of the snubber capacitors 5 and resistors 6.

Power supply for a high density discharge or fluorescent lamp

Abstract: POWER SUPPLY FOR A HIGH INTENSITY DISCHARGE OR FLUORESCENT LAMP This power supply for a high intensity gas discharge or fluorescent lamp exhibits near unity power factor with no third harmonic distortion, and facilitates highly efficient lamp operation with dimming capability, This is achieved by using an inverter to drive a resonant network that includes the lamp load. A feedback circuit adjusts the switching rate of the inverter to equal the resonant frequency of the network. Sinusoidal output voltage is achieved, together with voltage multiplication to a level sufficient to ignite the lamp and keep it lit during dimming. The inverter is driven by a switching regulator that is supplied with unfiltered, rectified ac power. A filter capacitor, connected across the regulator output, is sufficiently large so as to filter at the frequency of the rectified ac input. The regulator switching duty cycle is controlled in response to the average dc level across this filter capacitor. Lamp dimming is achieved either by adjusting the switching regulator dc output level or by varying the duty cycle of the inverter. The high power factor low distortion regulator concept may also be applied in other application where direct current power is derived from an ac line. -i-

Circuit for the remote DC supply of electronic apparatuses

Abstract: In a circuit for the DC supply of electronic apparatuses, a series circuit consisting of a current source (Q) and a resistor (R) is connected in a lateral branch of the pulse line. The collector-base junction of a transistor (T) is connected in parallel to the current source (Q), and a filter capacitor (C1) is connected in parallel with the resistor (R). A further filter capacitor (C2), from whose terminals the supply voltage (U0) is picked off, is connected in the lateral branch of the pulse line via the collector-emitter junction of the transistor (T). The signal-pulse pick-off from the lateral branch of the pulse line for the electronic apparatuses which are supplied with DC current takes place via a pulse decoupling capacitor (C3). Use: remote-working systems.

DC to DC power supply - has inductor as pre-inverter circuitry and drives inverter so that on-times of opposite transistors overlap

Abstract: The power supply circuit includes a DC voltage source (S1) connected in series with an inductor (L2) across an inverter circuit including switching transistors (Q6, Q7, Q8, Q9) The switching transistors (Q6-Q9) are connected to provide paths through a primary winding (P) of a transformer (T). The secondary winding (S) is connected to a full wave rectifier (FWR) which supplies a power to load resistor in parallel with a filter capacitor (C2). The voltage across the load resistor (RL) is measured by a regulator (REG2) which provides switching inputs to the bases of the switching transistors (Q6-Q9). The switching pairs of transistors (Q6, Q7, Q8, Q9 are conducting during overlapping intervals. The (L2) acts to constrain a rapid increase in current, so eliminating the possibility of destroying the switching transistors even though they are conducting coincidentally.

Generalized method of analysis of chopper-fed dc separately excited motor under regenerative braking

Abstract: A generalised method of analysis for predicting performance of d.c. separately excited motor under regenerative braking controlled by load current commutated chopper, has been presented. It has been shown that the source inductance, in the absence of filter capacitor at the source terminals, considerably influences the chopper commutation and machine performance. It has experimentally been shown that the use of a suitable filter capacitance at the source terminal neutralizes the effect of source inductance. Calculated characteristics agree well with the experimental results

Control system for air conditioning machine

Abstract: PURPOSE:To simplify a work at site and perform a comfortable control with an increased volume of control signal by a method wherein signals between the separated units of a split type air conditioning machine are overlapped in a line for DC power supply and then fed. CONSTITUTION:Out-door unit 1, in-door unit 2, and a remote control unit 3 are connected by a line 4 for a DC power supply. Power supply 5 connected through DC stabilization power supply circuit 6 is applied as a driving power supply for each of the units 1-3 and then the control units 7a-7c for each of the units 1-3 are driven. The overlapped signals are fed to the transmitting/receiving circuits 9a-9c through each of the filter capacitors 8a-8c, and the signals from the transmitting/ receiv ingcircuits transmit digital signals to each of other units through the filter capacitors 8a-8c. Each of the units is provided with input units 10a-10c, output units 11a, 11b and a display unit 12.

Use of PVDF film in high energy density capacitors

Abstract: Insulating films with high relative dielectric constants are used in capacitors when the requirements call for high energy density. Polyvinylidene Fluoride (PVDF) film is of interest in these applications because its dielectric constant is about 10 compared to usual values of 2 to 4. This paper is a summary of Maxwell's recent experience with this film. In part, this experience results from the development of capacitors which are used in pulsed plasma thrusters. Those capacitor specifications are shown in Table 1. Due to the long life requirements, life predictions are made from accelerated tests. On this basis, the recent data indicates that Maxwell has refined its manufacturing procedures to the point where the life and voltage specifications can be met. In addition to the life requirement, these spacecraft capacitors must be radiation resistant. To accomplish this, the capacitors must be paper-free because paper is known to be vulnerable to ionizing radiation.

Ignition power supply and switching for IC engine - uses two storage capacitors discharged in parallel by two thyristors through prim. winding of induction coil

Abstract: In the ignition system two capacitors (10 ,11) are charged from an alternator (14) through a diode network (12,13). Alternate half cycles charge alternate capacitors. In series with each capacitor is a thyristor (18,19) with cathodes connected to one end of the induction coil's prim. winding (15a). In response to a signal from the timing circuit (20-25) both thyristors are triggered into conduction simultaneously and discharge the capacitors into the induction coil to break over the sparking plug (17). The proposed circuit utilises both positive and negative half voltage waves from the generator, and enables a higher effective energy discharge into the coil. The thyristors are positively turned off at the end of each conduction period.

D.c. power supplies

Abstract: The drawing shows the circuit diagram of a DC power supply operated from an AC current source The source is connected to a full-wave rectifier comprising diodes D3, D4, D5, D6 through isolation capacitors C11, C12 and the DC output is smoothed by the filler circuit comprising resistor Rf and capacitor Cf The output terminal 19 of the rectifier is coupled back through the half-wave rectifier comprising diodes D1 D2 to the input terminals of the capacitors C11, C12 The current return diodes D1, D2 prevent a voltage potential reversal across the capacitors C11, C12 and enable polarized capacitors to be used The use of more efficient polarized (DC) capacitors as the AC isolation element, provides surge limiting protection and larger currents at reduced costs

TV vertical sweep device - has chopper supply and separate inputs to static and dynamic loop feedback paths

Abstract: The device supplies the vertical deflection coil (10) in series with a coupling capacitor (19) and measuring resistor (20). S-corrected sawtooth signals at the field scan frequency are produced by an oscillator (22) which controls the chopper (16) via a filter capacitor (26), amplifier (24), adder (30), reference comparator (35) and voltage-to-time convertor (37). The adder (30) combines the oscillator signal with the low-pass-filtered voltage across the coupling capacitor (19). The current through the coil (10) is locked to the oscillator sawtooth in a dynamic loop, and the mean voltage of the coupling capacitor is held constant by a separate static feedback loop. The filtering capacitance (26) can be chosen so that the sawtooth signal is not distorted. The device is incorporated in a TV receiver.

Controlling device for chopper used on electric rolling stock

Abstract: PURPOSE:To obtain the stabilized braking control performance for the subject controlling device by a method wherein an overvoltage suppressing device consisting of a series circuit having a resistor and a thyristor is connected in series to a plurality of filter capacitors, and at the same time, the turn-on of thyristor is selected in proportion to the regenerative current and the regenerative voltage. CONSTITUTION:The overvoltage suppressing device, consisting of series circuit of overvoltage suppressing resistors 8a-8n and overvoltage suppressing thyristors 7a-7n, is connected to a filter capacitor 6b in parallel. Then, when the overhead voltage exceeds the prescribed voltage due to the reduction in regenerative load, the thyristor to be used to suppress overvoltage is turned on, and in this instance, each overvoltage suppressing thyristor is to be selected so that the same current as one which blows at the time when the generative current and the overvoltage are detected will blow. Through these procedures, as there is no change in the circuit current of the main motor, stabilized braking force can be obtained, and at the same time, no wasteful current flows in from the overhead line.