Showing papers on "Voltage drop published in 1982"

AC Transistor switch with overcurrent protection

Abstract: An AC transistor switch is provided with simple, accurate and fast overcurrent protection circuitry. A pair of transistors are connected in anti-series across an AC load line, and each transistor has an anti-parallel diode therearound conducting current in the alternate half cycles. Comparator means senses current flow through the diodes and is responsive to given threshold overload current to turn off the transistors. Voltage sensing means is referenced to a common point between the series connected transistors and senses the voltage at each main terminal relative to the common point to thus sense the voltage drop from the common point across each diode to its respective main terminal for sensing current flow through the respective diode. The current representative voltage is sensed through respective dedicated third and fourth diodes connected to the main terminals and having a common anode connection to the voltage sensing means such that the latter senses the more negative of the main terminals regardless of the relative potential therebetween.

Barrier voltage and its effect on stability of ZnO varistor

Abstract: The major voltage drop in ZnO varistors occurs across the grain boundaries, which behave generally as Schottky barriers supporting a barrier voltage Vg. This voltage is proportional to the device voltage. Experimental evidence shows that there is a time‐dependent reduction in the barrier voltage combined with an increase in resistive current iR when the varistor is subjected to a continuous ac voltage stress. The phenomena is reversed when the applied voltage is removed, showing nearly complete recovery. Instabilities of the resistive current and of the barrier voltage are shown to be manifestations of the same phenomenon and are attributed to a metastable component in the Schottky barriers. It is proposed that this metastable component is due to interstitial zinc ions that are capable of migration under thermal and electrical driving forces. When these ions are removed or stabilized by a suitable heat treatment, the instability of the device is reduced. This paper presents experimental data and analysis to support this hypothesis.

Analysis of Breakdown Phenomena in MOSFET's

Abstract: An accurate two-dimensional self-consistent numerical model for MOS transistors which is able to predict avalanche behavior is presented. This model aims at a more principal understanding of the physical processes which arise from the avalanche effect and which eventually lead to breakdown. The system of the fundamental semiconductor equations with several generation/recombination mechanisms is solved. To improve the description of the ionization process, correction terms are introduced which account for the fact that the gate induced field does not cause ionization. Holes which are generated in the pinch-off region by impact ionization cause a bulk current; the voltage drop at the parasitic bulk resistance initiates an internal feedback mechanism. Thus a negative resistance branch of the drain current characteristic can arise. However, at high current levels, introduced by a high gate bias and/or a short channel, this snap-back effect is often counterbalanced by strong recombination. Snapback voltage can be estimated with this model.

The Effects of Voltage Reduction on Distribution Circuit Loads

Abstract: One method of obtaining energy conservation and peak load reduction is through a reduction in voltage on the utility distribution circuit This paper describes a voltage reduction program which included circuit testing to determine voltage reduction effects, data analysis to isolate the sensitivity of loads to voltage, and circuit analysis to determine categories of loads The actual tactics used to effect the desired reduction in voltage and consumption are also described

Power sensing circuit and method

Abstract: A power sensing circuit and method responsive to applied circuit voltages such that subsequent circuitry will be immediately powered down when the applied voltage drops below a specified level and generating a predetermined delay for powering up the subsequent circuitry when the applied voltage rises back to the same specified level.

Drive circuit for thermal printer

Abstract: An electrode drive configuration for a resistive ribbon thermal printer utilizes as a feedback a monitored signal representative of an internal ribbon voltage at the print point A monitoring contact is preferably located on the opposite side of the printhead from the drive signal return contact and the feedback signal is used to cancel the effects voltage drop variations in the common return portion of the drive signal path

Microwave proximity sensor

Abstract: Microwave oscillator means wherein the resonant frequency determining element is a 1/2 or 1/4-wavelength folded dipole antenna that also serves as the transmitting and receiving antenna, capacitor means that is alternately charged and then discharged through said oscillator means until the voltage drops so low that oscillation ceases at which point the capacitor is charged again, negative peak follower means to convert the minimum voltage across the capacitor into a DC voltage, and comparator means to detect changes in the output voltage of the peak follower caused by the approach of a person or object to the 1/2 or 1/4-wavelength antenna.

Time-delay current sensing circuit breaker relay

Abstract: A circuit control device combining the functions of a current sensor, a time delay circuit, an undervoltage sensor, and a lockout such that, once tripped, the device must be reset intentionally. The current sensor includes a coil (16a) surrounding two reed switches (18, 20), the reed elements (18a, 20a) of each of which being perpendicular to those of the other for vibration resistance. The coil is then surrounded by a magnetic shield (28) in order to shield out some of the leakage flux from the main relay coil (14c). The time delay circuit includes a PUT (Q1) which compares a steady voltage from a voltage divider network with the increasing voltage across a capacitor (C3). The undervoltage sensor includes a second PUT (Q3) which compares the voltage of the DC source (10) with the steady voltage across a zener diode (D5). In each case the cathode of the PUT is connected to the gate of an SCR (Q2) which, when gated "ON," energizes the trip coil (24c) of the latching relay (24), which in turn opens the main relay (14). This also closes another set of contacts (24e, 24f) in the latching relay, which activates a visual "tripped" indicator. The device also includes a reset coil (24d) to reclose the latching relay, an override switch (SW3) to energize the main relay coil regardless of the status of the latching relay, and an energy-storing capacitor (C2) to power the time delay circuit even when the DC source voltage drops too low to do so.

Protection circuit for memory programming system

Abstract: A protection circuit inhibits the generation of a write-erase signal to an E2 PROM when the logic supply voltage falls below a predetermined threshold level. A differential-input amplifier compares the logic supply voltage with a fixed potential and when the logic voltage drops below the threshold, a transistor coupled to the write-erase signal generator switches to its conductive state inhibiting further occurrences of the signal.

Semiconductor integrated circuit

Abstract: PURPOSE:To realize a semiconductor integrated circuit in a CMOS structure, wherein a freedom degree in design has been enhanced and a large scale integration and a higher- performance actuation have been contrived, by a method wherein a fundamental cell is used as a symmetrical pattern in between mutually adjacent cell rows, the cell rows are mutually arrayed in close contact, and also, a wiring is arranged on the cell rows in a multilayer structure. CONSTITUTION:A P type layer 34 and an N type layer 36, by both of which a P type well 32 and an N type Si substrate 31 are respectively connected to a power supply line VSS and a power supply line VDD, are provided in the vicinity of the boundary between each element region. By this CMOS structure, when a transistor TN is turned to ON, collector current runs through the N type Si substrate 31, but this current is supplied from the N type layer 36. Accordingly, voltage drop due to a resistor RN is less and forward bias, which is impressed on a transistor TP, is less, while when the transistor TP is turned to On, current runs through the P type well 32, but the current is absorbed in the P type layer 34, the voltage drop at a resistor RP is less and the forward bias, which is impressed on the transistor TN, is less. Accordingly, the positive feedback gain of the parasitic circuit is less. As a result, it becomes difficult for the latch-up phenomenon to generate.

Level shift interface circuit

Abstract: A voltage dropping element is connected in series with the conduction paths of first and second IGFETs, of complementary conductivity, between first and second terminals coupled to first (e.g. 5 volts) and second (e.g. 0 volt) voltage levels, respectively. The gates of the IGFETs are connected to an input terminal to which is applied TTL level signals (e.g. 0.4 to 2.4 volts) and their drains are connected to an output node. When the "high" TTL level (e.g. 2.4 volt) is present, the voltage dropping element reduces the effective gate-to-source voltage (VGS) of the first IGFET, reducing its conductivity, increasing its effective impedance substantially, and enabling the second IGFET to drive the output node to the second voltage level with little power dissipation. When the "low" TTL input (e.g. 0.4 volt) is present, the second IGFET is turned-off while the first IGFET is turned-on, driving the output node to the voltage at the first power terminal less the voltage drop of the voltage dropping element. A regenerative latch circuit connected to the output node senses the turn-on of the first IGFET and couples the output node to the voltage at the first power terminal eliminating the voltage offset at the output node due to the voltage dropping element.

Process and apparatus for determining the state of charge of a battery

Abstract: A process and apparatus for determining the state of discharge of an electric battery by measuring the voltage drop associated with changes in its internal resistance. According to the process, the battery is periodically connected to a reference load for a brief interval during which the voltage at the terminals of the load is measured. The measured analog voltage is converted to a digital signal which is compared to a number of pre-programmed digital levels to determine the state of change of the battery. The apparatus comprises a commutation component controlled by a logic signal, a reference load, a sampler-and-hold circuit, an analog-to-digital converter and a comparator which can be programmed at n levels. The apparatus compares digital signals corresponding to the voltage at the terminals of the reference load with the n programmed levels of the decoder and a signal is generated indicating the level of the electric battery with respect to the levels programmed into the comparator.

Sense amplifier for use with a semiconductor memory array

Abstract: A sense amplifier (124) for use in determining the binary state of a selected storage device (4) in a semiconductor memory array (2) is disclosed. The sense amplifier (124) comprises a sensing section (150), a reference signal generator (148), and an inverting amplifier section (152). A relatively small current transistor (164) connected between a source of operating potential (158) and a voltage node (162) in the sensing section (150) supplies read currents to the selected storage device (4) via an enabled bit line (8) in the array (2). A second transistor (168) of relatively large size connected to the voltage node (162) in parallel with the current transistor (164) operates to rapidly raise the potential on the bit line (8) when the bit line (8) is first enabled. A third transistor (166) also of relatively large size connected between the voltage node (162) and the bit line (8) serves as a transfer gate for read currents. The reference signal generator (148) feeds a reference potential V ref to the control gates of the second and third transistors (168, 166), thereby establishing a quiescent bit line potential. The binary state of the selected storage device (4) can then be ascertained by sensing whether the voltage at the voltage node (162) drops in response to current flow through the enabled bit line (8) and selected storage device (4). Any voltage drop at the voltage node (162) which does occur is detected and amplified by the inverting amplifier section (152) of the sense amplifier.

Standby power system

Abstract: A standby AC electrical power system connected between a load device and the AC line voltage comprises a voltage responsive control circuit connected between the AC line voltage source and a DC to AC inverter circuit. The control circuit generates a continuously pulsating DC control voltage which has an envelope which responds to and follows but at a different rate the increase and decrease in the envelope of the output of a full wave rectifier fed by the AC line voltage. The control voltage remains above a given triggering level when the average value of the rectified output for the current half cycle involved stays above a given monitored level indicating that the average value of the current half cycle of the AC line voltage is above a given low level and drops to the triggering level when the average value of the current half cycle of the AC line voltage drops to the given low level. The circuit which generates this control voltage comprises a multi-branched capacitor charge and discharge circuit having a first relatively long time constant producing branch which provides a relatively slowly increasing envelope in response to the rise in the envelope of the rectified output of a relatively short time constant producing branch which provides a relatively rapidly decreasing envelope in response to the drop in the envelope of the rectified output. A trigger circuit responds to the dropping of the envelope of the control voltage to the triggering level by connecting a DC battery to the DC to AC inverter circuit which then supplies an AC voltage to the load device.

Power source system for vehicular electronic device

Abstract: Herein disclosed is a vehicular power source system which uses as its load a memory-arithmetic circuit (5) such as a microcomputer. An electric power is supplied to the load (5) through a diode (6) and a constant voltage circuit (4), when a switch (2) for running the vehicle is open, but a booster (3) is operated to supply the power when the switch (2) is turned on. The voltage drop of a battery (1), which may be caused during the running operation of the vehicle, is not transmitted to the load (5), but a constant voltage is supplied to the load (5) at all times so that the storage data of the memory unit (5) is always held.

Control apparatus for charging generator

Abstract: A control apparatus for a charging generator for charging a battery comprises a first temperature detecting element having a positive temperature coefficient which detects the variation of ambient temperature of a voltage regulator to impart a negative temperature gradient to the voltage adjusting characteristic of the voltage regulator and a second temperature detecting element having a negative temperature coefficient which detects the self-heating of the generator or the voltage regulator during operation to impart a positive temperature gradient to the voltage adjusting characteristic so as to control the output voltage of the generator. This control apparatus has a dynamic characteristic permitting the adjusted voltage to increase so as to compensate the voltage drop in the external load characteristic; thus an excellent charging characteristic of the battery can be attained.

Voltage Recovery Time of Small Spark Gaps

Abstract: A two-pulse method is used to determine how fast and to what degree a small spark gap can recover its voltage holdoff capability after breaking down. The first pulse is used to overvolt and break down the gap. The second pulse is used, after a time delay, to determine the voltage recovery of the gap. By varying the time delay to the second pulse, a recovery voltage versus time plot can be obtained. Time delays from 10 ?s to 100 ms have been recorded. The spark gap discharges millijoules of energy with a gap spacing of less than 1 mm. Recovery has been measured at breakdown voltages of up to 10 kV in argon, hydrogen, and a mixture of the 2 gases. The experimental setup, pulse circuits, and data collection methods are described. Percent voltage recovery versus time plots for various parameters (gas species, gap spacing, and pressure) are discussed.

Mos output driver circuit avoiding hot-electron effects

Abstract: An output driver circuit for a Mos integrated circuit eliminates the problem of charge injection into the substrate by employing a switching circuit responsive to the voltage on the output node to control the voltage drop on the output transistor.

High voltage insulator assemblage having specially-chosen series resistance

Abstract: The invention relates to an outdoor high voltage insulator, wherein the flashover due to the effect of external layers or deposits of pollution is prevented or at least shifted in the direction of higher degree of pollution. A resistance element (1) is connected in series with the insulator itself (2), with the leakage current prior to flashover producing a voltage drop over the resistance element (1). This voltage drop reduces the voltage on the insulator and prevents or retards flashover.

Data processor with R/W memory write inhibit signal

Abstract: A main power source voltage is compared with a reference voltage, when the main power voltage drops lower than the reference voltage, an operation/halt signal is formed, a read/write memory write inhibit signal is formed in response to the operation/halt signal, and the read/write memory is inhibited in operation. This write inhibit signal is formed by setting a D-type latch at the timing of the transition of the NIF signal to active mode.

Test contact resistance of dry circuit contacts

Abstract: In the testing of dry circuit contacts, a constant current source is applied to the contacts The open circuit voltage of the source is set to a predetermined maximum value and then the short circuit current at the contacts measured If the current value is below a predetermined maximum value, the voltage of the source is increased to bring the short-circuit current to the predetermined value The voltage drop across the contacts is then measured and the contact resistance calculated This arrangement makes adjustments to take into account variations in the test circuit, such as different lead lengths and other variables, without subjecting the contacts at any time to an open circuit voltage or short circuit current above maximum values

Power supply having automatically varied primary turns

Abstract: A transformer has a primary and a secondary. The primary is supplied by a source and is divided into permanent and selectable turns. Switch circuitry is connected by taps to the segments to selectively energize or de-energize them. The secondary is connected by a rectifier and filter to a voltage regulator which supplies a constant voltage to a load. Circuitry senses the voltage drop across the voltage regulator and comparator circuitry compares the series regulator voltage drop to reference values. The comparator generates error signals whenever the voltage drop falls outside of a desired range above the drop-out voltage of the regulator. The error signal is transmitted to an up/down counter which correspondingly increases or decreases its count. The count of the up/down counter is decoded by switch control circuitry to open and close the appropriate switches S 1 -S 6 to energize the desired turns of the primary to bring the series regulator voltage drop back within the desired range.

Winding voltage balancing circuit for brushless DC motor

Abstract: In a brushless DC motor having a magnet and multiphase coils, a current is distributed from a DC voltage source to the multiphase coils according to a set of output signals of a position detector for detecting the relative position between the magnet and the multiphase coils. First and second sets of output transistors are used so as to distribute a current to the corresponding multiphase coils. A first distributor selectively activates the first output transistors corresponding to the output signals of the position detector so as to supply the multiphase coils with a current according to a command signal, and a second distributor also selectively activates the second output transistors corresponding to the output signals of the position detector. A second distributor has a voltage drop controller for detecting voltage drops across the first set of output transistors (or the second set of output transistors) in each activated period and for controlling output currents of the second set of output transistors so as to maintain the voltage drops across the first set of output transistors (or the second set of output transistors) in each activated period at a predetermined value regardless of the relative position between the magnet and the multiphase coils.

Energy transfer unit between superconductive coils

Abstract: PURPOSE:To transfer a magnetic energy of one superconductive coil to another superconductive coil efficiently at a short time by changing a current passage through igniting SCR properly according to a charging voltage of capacity. CONSTITUTION:An energy is stored in a superconductive coil 23 by excitation through a switch 22. From igniting SCR's 27, 28, a capacity 29 is charged and whenever it reaches a permissible voltage V1, SCR 24 is ignited, and the SCR 27 is turned off by a close loop current of the coil 23. An energy of the capacity 29 is transferred to a coil 25, and when voltage drops down to a given negative voltage V2, the SCR 27 is turned on and the SCR 24 off, which is repeated. Next, where current of the coil 25 becomes larger, the capcity 29 is charged to negative when the SCR's 27, 28 are kept ON, and whenever it reaches the given voltage V2, SCR 26 is turned ON and SCR 28 OFF. The capacity is resupplied with energy from the coil 23, and when it reaches the voltage V1, the SCR 28 is turned ON and the SCR 26 OFF; when it drops to the voltage V2, the SCR 26 is turned ON. All quantity of energy in the coil 23 can thus be transferred to the coil 25 through repeating the above process.

Optically coupled input circuit for digital control

Abstract: An a.c. input circuit for converting a sensed a.c. voltage into a logic level voltage includes a rectifier for converting the sensed a.c. voltage to a d.c. voltage which is supplied through a coupling impedance to the light emitter of an optical isolator. While the a.c. input voltage is below a first predetermined voltage, a switchable low impedance circuit path in parallel with the light emitter is rendered conductive to maintain a low impedance across the light emitter to prevent the light emitter from becoming conductive. A switchable high impedance circuit path in parallel with the switchable low impedance circuit path becomes conductive once the sensed a.c. input voltage reaches the predetermined voltage to drive the light emitter into hard conduction. The switchable high impedance circuit path remains conductive until the sensed a.c. input voltage drops below a second predetermined value, at which point the light emitter is turned off and the switchable low impedance path becomes conductive.

Apparatus for measuring ion concentrations

Abstract: An apparatus for measuring ion concentrations using the voltage, originating from an electromotive force, between two electrodes (1, 2) immersed in a sample solution (3) comprises a device for measuring the internal resistance of the source of the electromotive force. The device for measuring the internal resistance comprises a current source (8) for generating an alternating current between the electrodes (1, 2) whose output voltage is an alternating voltage which has a direct voltage (EPH) corresponding to the electromotive force superimposed on it. A measurement circuit (11) measures the voltage drop produced across the internal resistance by the alternating current.

High voltage on chip FET driver

Abstract: High voltage tolerant FET circuits are characterized by the use of shield structures surrounding source/drain diffusion pockets, with the shields tied to apropriate potentials, which in some cases is the associated gate potential. Some embodiments use enhancement mode devices which however have implanted channels underlying the shield structures. Operation of several embodiments is achieved near the snap-back limits by the use of a clamp to maintain potential drop below this limit. High voltage switching at heavy loads is achieved by a voltage divider providing appropriate gate potentials to the load carrying FETs.

Study of Universal Motors with Lag Angle Brushes

Abstract: A drawing procedure of vector diagrams is presented for the performance analysis of universal motors with lag angle brushes. Using this procedure, some examples are described. They are brush voltage drop, leakage reactance, iron loss angle, and mechanical loss separation etc.

Back-up system of control computer for efi engine

Abstract: PURPOSE:To maintain the normal running of an engine by outputting a fuel supply timing signal corresponding to the revolution of the engine when the power source voltage drops below the predetermined level CONSTITUTION:When a battery voltage detector 1 detects the voltage drop of the battery voltage V below the standard voltage Es, an AND gate 2 is closed and an AND gate 3 is opend thereby cutting off the fuel injection signal T; from the computer and suppluing the fuel injection signal Tg from the back-up system to a driver 5 through the AND gate 3 and an OR gate 4 Thus, the normal running of the engine is maintained