Showing papers on "Voltage drop published in 1978"

Apparatus and method for calibrated testing of a vehicle electrical system

Abstract: This specification discloses a vehicle electrical system tester which connects in parallel across the vehicle battery and the portion of the electrical system to be tested and measures voltage changes upon selective actuation of portions of the vehicle electrical system. Comparison of these measured voltages with predetermined values is used in evaluating whether the electrical system is operating properly. The method of testing using the apparatus includes measuring a first voltage level after connection of the apparatus, actuating a portion of the vehicle electrical system, measuring a second voltage level, calculating a voltage difference as a function of the first and second voltage levels, comparing the voltage difference to a predetermined voltage magnitude, and determining if the actuated portion of the electrical system is operating properly. Additional sensitivity can be achieved by establishing a third voltage level through the use of a calibration resistor.

Numerical simulation of plasma double layers

Abstract: Numerical simulation results are presented for a plasma double layer, the computer model being a finite one-dimensional particle-in-cell plasma with specified potential difference across the system. A single pulse is formed which crosses the system with constant velocity; this is followed by the formation of a potential drop across a limited region of the plasma. An approximate expression relating the spatial extent of the double layer and the potential drop is presented. Electron and ion beams are generated which tend to lead to instabilities in the upstream and downstream regions.

Variable intensity control apparatus for operating a gas discharge lamp

Abstract: A gas discharge lamp is connected in parallel with an inductor and in series with a solid state switching device and a resistor, and this combination is connected across a rectified AC voltage source. This switching device is controlled by a monostable multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above-mentioned resistor and a voltage which bears a predetermined relationship to the rectified AC signal of said source. This results in a high frequency operation of the lamp wherein the lamp current level is controlled or modulated in accordance with the rectified AC supply voltage, providing a high power factor lamp circuit without the normal heavy lamp ballast. In addition, a circuit is disclosed which prohibits the lamp from exhibiting a high resistance when the AC voltage is at a zero crossing point, protecting the solid state switching device and stabilizing the high frequency.

Flow rate meter with temperature dependent resistor

Abstract: A flow rate meter for measuring the flow rate of a fluid medium, especially that of the air aspirated by an internal combustion engine A hot wire or film is placed in the air stream and is made part of an electrical circuit powered by the output of a differential amplifier The voltage drop across the resistor is monitored at the input of the differential amplifier where it is compared with fixed or compensated values In order to reduce the effect that airborne particles, which are deposited on the hot wire or film, have on the measuring characteristics of the apparatus, the wire or film are shaped so that their leading edge constitutes an area much smaller than the surfaces which are substantially parallel to the stream lines

Semiconductor radiation detector

Abstract: An electrical charge amplifier including a filter circuit is AC coupled to a semiconductor (CdTe) detector and generates a voltage pulse in response to an electrical charge generated in the detector by an incident pulse of radiation. The filter allows only frequencies within a predetermined range to contribute to the voltage pulse. The selected range of frequencies is determined in accordance with the duration of the incident radiation pulse such that the voltage pulse faithfully represents the magnitude of incident radiation in spite of undersirable detector characteristics which would otherwise introduce distortions. Exemplary charge amplifier and detector structures are also described.

Power line transient suppressors

Abstract: Power line transient suppressing circuits which use inductors in series w the load to reject or attenuate transients on the power line over a wider range of transients than with prior devices, and also serve as inrush current limiters. Two unidirectional current circulating diode-inductor loop circuits eliminate the 60Hz voltage drop across the inductors. Normal operation is not affected by the circuits, but transients are rejected by the inductors.

Analyzing electrical circuit boards

Abstract: Apparatus for analyzing electrical circuit boards by measuring the voltage drop due test currents flowing along a conductor to an IC mounted on a circuit board, comprising a probe having at least two contact tips mounted to simultaneously contact at least two points on the conductor, the tips being spaced apart sufficiently to permit measurement of electrical activity in a segment of the conductor between the tips, and means for injecting a test signal directly into the conductor via the probe, improved in that there are provided means for measuring a first voltage drop across a segment produced by the flow of test current through the segment away from the IC and a second voltage drop across a segment produced by the flow of test current through the segment into the IC, and means for determining the ratio R 1 /R 2 , where R 1 is the internal resistance of the IC and R 2 is the parallel resistance of all other ICs on the same node.

Optical memory with injection laser as light source and detector

Abstract: In an optical memory device, such as an optical video disk, an injection laser is used as the source of the light, as the detector of the light reflected from the memory element and as the detector for controlling the proper focus of the light on the memory element The light reflected from the memory element is fed back into the injection laser and variations in certain characteristics of the injection laser, such as the optical output at constant current, the electrical current through the laser at constant voltage and the voltage drop across the laser at constant current, are used to read the memory device and to maintain the focus

Analysis of the cathode fall in high‐voltage low‐current gas discharges

Abstract: An analytic investigation is made of the cathode‐fall region in high‐voltage low‐current gas discharges. Explicit expressions for the variation of electric field, voltage drop, charge density, Joule heating, and cathode‐fall thickness are obtained as functions of pressure, current density, gas properties, and distance from cathode. To first order, it is shown that the former two quantities depend on the two‐thirds power of the ratio of the current density to pressure squared, that the electric field varies linearly in the cathode‐fall region, and that the fall thickness is independent of the operating current and varies inversely with pressure. To illustrate the order of magnitudes involved, a numerical calculation is made using helium as the working gas.

Gas flow monitor

Abstract: A gas flow monitor which includes a sensor composed of a pair of identical parallel wires to be positioned in spanning relation of the flow path of a duct and a heater to heat the length of one of the closely adjacent identical wires and wherein a voltage measuring device is provided to measure the voltage drop and hence the resistance across each of the wires which are energized by a constant current source and are in series with one another so that, upon comparison of the two, the effect of increased air flow through the duct will affect both wire lengths equally and the effect of any increase in air flow through the duct will have a net effect only of offering the resistance of the heated length of wire by reason of heat exchange between the heated wire.

Remote sensing apparatus

Abstract: This relates to a circuit for generating a voltage which is proportional to changes in the resistance of a remote resistive sensing element, due to, for example, changes in temperature, pressure (such as from a strain gauge), etc. The sensing element is coupled to the circuit by three lead wires each having lead wire resistance. Means including first and second operational amplifiers are provided for cancelling errors in the output voltage due to voltage drops in the lead wires.

Energy limiting foldback circuit for power supply

Abstract: An energy limiting foldback circuit for use with power supply having a power control device in its output. The energy limiting foldback circuit contains a voltage sensing device for sensing the potential drop between the input and the output of the power control device. The foldback circuit also includes a current sensing device for sensing the current through the power control device. A conduction control circuit is included which is responsive to the outputs of the voltage sensing device and the current sensing device. The conduction control circuit acts to control the operating conduction through the power control device. The energy limiting circuit can also include a pulsing circuit operative in the event of output fault to periodically pulse the power control device into a momentary conduction state.

Symmetry regulated high frequency ballast

Abstract: A gas discharge lamp is connected across an inductor and in series with a solid state switching device and a resistor, and this combination is connected across a voltage source. This switching device is controlled by a monostable multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above-mentioned resistor and a reference voltage which may be changed to vary light intensity. A supply voltage feedback control loop uses a power oscillator to maintain the voltage supplied to the inductor and the lamp at a level corresponding to a symmetrical voltage wave form in the lamp in order to maximize lamp efficiency. A reference voltage feedback control loop controls the reference voltage supplied to the comparator amplifier in order to minimize the effect of power line variations on lamp intensity while allowing controlled variations in intensity by the user. The supply voltage feedback control loop provides an input impedance to a 60-Hertz power source which is exclusively resistive and non-reactive, thereby maximizing efficiency of the power supply.

Digital conductance meter

Abstract: Determining the value of resistance directly, but inversely, based on conductance measurements, rather than directly, based on resistance measurements, is disclosed. A voltage drop of one polarity across a referenced resistance controls the charge rate of the capacitor of an integrator of a dual slope analog-to-digital converter for a known period of time. Thereafter the capacitor is discharged to a predetermined level (e.g., zero) for a measured period of time at a rate determined by a voltage drop of opposite polarity across an unknown resistance. The measured period of time is directly related to the conductance value of the unknown resistance and inversely related to the resistance value. The time measurement is stored in latches, which control a digital display.

Circuit detecting earth faults in two=wire signal line - has resistor connected to each battery terminal and earthed in turns

Abstract: The line is supplied from a voltage source in a signal receiving station. A resistor (Ra, Rb) is connected to each terminal of the DC voltage source (Ba). They are alternately connected to earth by a switch (U). In case of an earth fault the voltage drop across the corresponding resistor (Ra, Rb) signals the fault. The voltage source (Ba) may be a battery. It is connected across two lines (a, b). There are two equivalent resistances (Ea, Eb) between the two signalling lines (a, b) and earth.

Analyzing electrical circuit boards

Abstract: Analyzing electrical circuit boards by providing a probe having at least two contact tips close enough to each other to simultaneously contact a lead of a mounted integrated circuit element, but spaced apart from each other sufficiently to permit measurement of electrical activity in the lead segment between the tips; and measuring the voltage drop between the tips resulting from the flow of test current through the resistance of the lead segment. In preferred embodiments the test current is injected directly into the lead through a third tip of the probe while the third tip is in contact with the lead at a point farther from the IC than the other two tips.

Contribution to the Study of Commutation in Small Uncompensated Universal Motors

Abstract: A method, is, given to: study the current reversals in a small. motor. The commutation process is shown to be widely different of what it is in a big motor ; as an example, the voltage drop across the sliding contact is small as compared to the inductive voltages aa an other example, there exist ripples of the input current which are at commutation frequency, and which play an important role in the conmutation process. The influence of the brush shift is discussed. An experimental verification is given.

Regulated power supply apparatus

Abstract: A power supply apparatus is disclosed including a device for producing an oscillatory signal, and an output circuit for producing from said oscillatory signal an alternating-current output voltage, characterized by the provision of a regulating unit connected in series with the output circuit for producing a controllable voltage drop. The regulating unit includes a control device operable in response to a signal derived from the output circuit for controlling the voltage drop in response to a change in an output parameter of the output circuit.

Photo oscillation circuit

Abstract: PURPOSE:To extend the range of incident photo strength to keep the oscillation, by providing a Zener diode and a capacitor between the negative power supply of the photo oscillation circuit consisting of NPN transistor Tr, PNPTr and photo diode, and NPNTr. CONSTITUTION:When incident light to the photo diode 4 is increased and the voltage drop consisting of the current in NPNTr1 and the resistor 8 is greater than the zener voltage of the Zener diode 5, back bias voltage is made between the emitter and the base of Tr1 to interrupt the collector current of Tr1. Thus, the voltage drop of the resistor 7 is avoided and the base potential of PNPTr2 is of the same potential as the positive electrode of the power supply 3, but the emitter of Tr2 is at lower potential than the base with the charging of the capacitor C6 and Tr2 does not turn on until C6 is finished for discharge with the photo current of the diode 4. Further, Tr1 does not turn on until the voltage across C9 is less than the Zener voltage. Tr1 and 2 are turned on, and this is repeated to cause oscillation state. The stop of oscillation is not caused even with strong incident light.

Parametric Study of Ozone Generation by Coronas

Abstract: It is shown that previous data on the ozone generation rate by dc coronas can be described by a simple model employing the following concepts. 1) The ozone generation rate is proportional to the electrical power dissipated in the ionization sheath surrounding the wire. 2) The voltage drop across the ionization sheath is proportional to the corona threshold voltage and independent of both the applied voltage and the corona current.

High intensity discharge lamp starting circuit

Abstract: A gas discharge lamp is connected across an inductor and in series with a solid state switching device and a resistor, and this combination is connected across a rectified AC voltage source. This switching device is controlled by a monostabile multivibrator, the input of which is connected to the output of a comparator amplifier sensing the difference between the voltage drop across the above-mentioned resistor and a voltage which may be selected to vary light intensity. The secondary winding of a step-up transformer connected to a capacitive discharge device is placed in series with the lamp. Control circuitry is provided to apply a large ignition voltage to the lamp while preventing damage to the switching device by simultaneously holding it in its conductive state. A diode rectifier provides an alternate current path across the secondary winding to prevent the inductance of the secondary winding from affecting normal lamp operation. Means are provided to cancel the contribution of lamp current to the voltage drop across the resistor sensed by the comparator, thereby rendering power consumed by the circuit independent of the effective resistance of the lamp.

Switching circuit for connecting an AC source to a load

Abstract: In the disclosed circuit, a bilateral breakdown switch such as a triac includes two terminals for connecting an AC source to a load. A variable input arrangement, such as one which includes an LED and a photoresistor, operates a control electrode on the switch to turn the switch on and off in response to an input signal. The switch is disabled when the momentary AC voltage exceeds a predetermined value. This is done by a sensor that senses voltage and a bilateral switching arrangement that responds to the sensor and turns off the switch in response to a voltage higher than a predetermined value. According to one embodiment, the bilateral switching arrangement is composed of two complementarily poled transistors connected in parallel with respective bases connected to the sensor. Series diodes provide unidirectionality for the transistors. Back-to-back parallel diodes connected to the control electrode compensate for the voltage drop caused by the series diodes.

Temperature compensated bridge circuit

Abstract: The voltage drops across a series-connected pair of strain gauges and arbitrary resistance are measured at zero and maximum stresses at three temperatures. The appropriate resistance for span compensation at the two extreme temperatures is then calculated from these values. The span compensation resistance is then distributed between a first resistor connected in series with one of the strain gauges and a second resistor connected in series with the other strain gauge. Initially, the first resistor is assigned a value of one ohm and the second resistor the remainder. With these values the series/parallel resistances required for temperature compensation at zero stress are calculated for the two extreme temperatures. The outputs at zero stress are then calculated for both the maximum temperature and the intermediate temperature and the difference between these outputs is obtained. Next, the resistance of the first resistor is increased by one ohm and the series/parallel resistances required for temperature compensation are again calculated for the extreme temperatures. From these values the outputs at zero stress are calculated for both the maximum and intermediate temperatures. The difference between these outputs is then compared with the difference previously calculated, and whichever value is closer to zero is retained along with the necessary circuit parameters. This process is repeated for each value of the first resistor less than the span resistance, so that the retained circuit parameters define the resistance values which produce the best three-point temperature compensation.

Low power dissipation series regulator for PCM repeater lines

Abstract: A current regulator for a pulse code modulated (PCM) transmission line is interposed between a voltage potential and a load (consisting of repeater amplifiers along the PCM transmission line) for limiting the current flow to the load. During normal operation, the regulator provides a relatively low impedance path from the voltage potential to the load through a series pass transistor and a sensing resistor. During an overload condition, which is sensed by the sensing resistor, the series pass transistor is deprived of base drive thereby providing a high impedance path with an accompanying increased voltage drop across the series pass transistor of the series regulator. This voltage drop is used to drive a timer which turns the series pass transistor off and on, with a low on time or duty cycle, in order to minimize power dissipation during the overload condition. After the overload condition has been alleviated, the series pass transistor is turned back on by the timer, and due to the low current flowing to the load, the series pass transistor is again returned to its relatively low impedance conducting condition.

Compact ballast for fluorescent lamp which provides excellent lamp power regulation

Abstract: Compact ballast circuit for operating a low-pressure fluorescent lamp wherein line voltage is from about 120% to about 150% of the lamp operating voltage. The compact ballast comprises a positive temperature coefficient (PTC) resistance means and a parallel-connected fixed resistor, both connected in series with the ballasted lamp. Room temperature ohmic resistance of the PTC resistor is from about one-third to about twice the ohmic resistance of the fixed value resistor and the ohmic value of the fixed value resistor is sufficiently low that it will pass sufficient current to sustain the lamp discharge. The voltage drop across the combined ballast resistors is at least about 20% of the voltage across the operating lamp. The PTC resistor is selected to display a curve of resistance versus temperature which breaks and rises sharply after a predetermined operating temperature is achieved and the PTC resistor is associated with a heat sink to cause it to operate at about this transition temperature so that the operating PTC resistor has a relatively constant power dissipation within the range of from about one-third to about one-tenth of the rated lamp power consumption. The power regulation of the circuit is excellent under conditions of varying line voltage.

Meter for fuel level in tank - has temp. sensitive resistor immersed in liq. and supplied with constant current

Abstract: The fuel gauge incorporates a sensitive resistor with a heating system. A meter displays the resistance change caused by change of the liquid level. The temp. sensitive resistor (WI) consists of an insulating foil (3) and a metal layer (2) with a high temp. coefficient. A current source (1) is connected to this resistor. it delivers a current independent from the liquid level, and voltage drop across the resistor is the measure for the level. The insulator is typically plastics. The voltage change is measured by an indicating meter (4).

Constant voltage circuit

Abstract: PURPOSE: To get rid of the influence due to power supply variation by detecting the current change of the current mirror circuit which is caused by power supply variation, and providing negative feedback to the current setting transistors of the current mirror circuit. CONSTITUTION: Voltage of a portion for two diodes is set up in the terminal 10 by transistors 13 and 6, and it is output from the terminal 11 through the emitter- follower. When the power supply voltage Vcc rises, the collector current I c2 of the transistor 2 is increased by an early effect. And the base potential of the transistor 4 is lowered due to a voltage drop of the resistor 12, and the collector current I c3 of the transistor 3 is decreased. Accordingly, the current I c2 is also decreased, and the early effect is negated. As mentioned above, since negative feedback has been provided to the current mirror circuit (transistors 2 and 3), the constant voltage output characteristics are elevated. COPYRIGHT: (C)1980,JPO&Japio

Method and glow-suppression devices for transporting a gas across a voltage drop

Abstract: Method and device (10) for suppressing sputtering glow in a gas to be transported across a voltage drop region (X-Y) under conditions where the gas would otherwise tend to support a glow discharge. The device includes an insulating member, such as a plastic tube (70), having a passage for transporting the gas across the voltage drop, the passage being packed with a porous insulating material, such as fiberglass strands (71), arranged so as to suppress glow discharge in the gas. Preferably, the insulating material is arranged so that there is very little pressure drop across the insulating member. In specific embodiments, the suppression device is used in a gas feed line (11) for supplying a sputtering gas, such as argon or a mixture of argon and nitrogen, or argon and oxygen, to a negatively charged cathode cell (12) of a sputtering machine (13), at very low absolute pressure.

Vehicle lighting monitoring system - uses bulb failure voltage difference to activate warning circuit

Abstract: The head lamp dipper, the side light, tail light and brake light circuits have separate test circuits. Each test circuit is connected to the emitter of a transistor whose collector is in contact with the vehicle battery via a fuse. The four transistors have a common switch, their bases being connected via resistances whose values correspond to the respective lamp filaments to the contacts of a time switch. The lamp voltage drop is passed by individual trim potentiometers to an OR-gate input and adjusted to give a tension below the normal value of that when the lamps are functioning correctly, and above when one or more filaments fails.