Showing papers on "Voltage droop published in 1973"

Solid state thermostat with droop compensation

Abstract: A solid state thermostat which has a temperature compensating arrangement for the heat generated by the output solid state triac. The temperature compensating arrangement eliminates the droop or offset that would otherwise be created by the heat from the solid state switch affecting the temperature sensor, shown as either a negative or a positive temperature coefficient temperature sensitive resistor.

Alarm circuit for monitoring the amplitude of a-c voltages

Abstract: A circuit for rapidly and accurately indicating whether an a-c voltage has a magnitude greater than a predetermined minimum value. A two-state voltage comparing circuit establishes a first output voltage when the rectified a-c input voltage exceeds a preset reference voltage and establishes a second output voltage state when the rectified a-c input voltage is less than that reference voltage. A two-state switching circuit forces the comparing circuit to assume and remain in its first state for a preset time after it assumes its second state, the preset time being greater than the time required for an acceptably high a-c voltage to pass through the reference voltage region established by the comparing circuit, as the a-c voltage varies through zero volts twice during each full cycle thereof. A two-state output control circuit indicates an a-c voltage fault if and when the comparing circuit returns to its second state within a relatively short time after having been forced to assume its first state. In this manner actual a-c voltage faults are distinguished from the apparent a-c voltage faults which tend to occur each time the a-c voltage varies through zero.

Elastomeric helicopter rotor head with dynamic and static blade coning and droop stops

Abstract: An elastomeric helicopter rotor having a blade mounted by means of an elastomeric bearing for universal motion about the intersection of the blade pitch change, flapping and lead-lag axes and including blade coning and droop stops, including a conical ring member rotatably mounted about the pitch change axis of the blade and coning and droop stops constituting circular segments of conical members whose centers lie on the blade leadlag axes and with the ring member and coning stop and droop stop members presenting mating surfaces to one another so that as the blade moves in lead-lag motion while the blade ring member is in contact with either the coning stop surface or the droop stop surfaces, a relative motion will be established therebetween for full support of the blade throughout the lead-lag motion, without affecting blade pitch angle or flapping angle, without preventing independent blade pitch change and without scuffing of parts. Most importantly, the droop stops are both a dynamic droop stop supported from the hub for limiting blade droop during flight, and a static droop stop supported loosely from and pivotable on said dynamic droop stop, for further limiting blade droop at low rotor speeds or at rotor rest, so that blade loading against said static droop stop will move said static droop stop into engagement with said dynamic droop stop to impart said load directly through both droop stops so engaged into the hub. The loose pivot between the static and dynamic droop stops involves substantial diametral clearance providing for almost frictionless operation of the static droop stop, and causing the blade load to bypass the pivot connection. The looseness of the pivot connection and the shape of the static droop stop will accommodate misalignment between the contacting surfaces. This misalignment, which is allowed by the flexibility of the blade supporting elastomeric bearing, will cause the static droop stop to rotate on the dynamic droop stop and realign itself under load, and provide proper contact rather than corner loading.

Power supply over voltage protection system

Abstract: A power supply system is disclosed having a plurality of voltage regulator circuits connected in parallel with each other between a source of unregulated voltage and a load. Each of the voltage regulators includes an over voltage protection circuit whereby a particular regulator is taken out of service when the current in that regulator exceeds a certain level and the voltage across the load is at a first level. The regulator is not taken out of service when the current through the regulator is below the certain level and the voltage across the load is above the first level but below a second, higher, level.

Monolithic integrable series stabilization circuit for generating a constant low voltage output

Abstract: A series stabilization circuit for generating a regulated voltage in the order of one volt. In order to reduce variations in the output voltage due to changes in temperature, the reference voltage used is a combination of the outputs of two reference voltage sources. The first reference source has a negative coefficient of voltage such that its output will decrease when temperatures increase. The second reference source has a positive coefficient of voltage such that its output will increase as temperature increases thereby resulting in a balanced overall reference voltage.

Voltage failure sensing circuit

Abstract: A circuit for sensing voltage failure in a multiphase conductor electric power supply. Voltage failure of any of the phase conductors to a value less than a predetermined voltage serves to de-energize a sensing means, which preferably comprises a solenoid in control circuit relationship with a load connected to the power supply.

Start-up control circuit for SCR deflection

Abstract: A boost voltage delay circuit for deflection circuit utilizing trace and commutating switches to generate deflection current in a deflection winding. A supply voltage boost circuit derives voltage from an inductor coupled between the direct current voltage supply and the commutating switch, boosts and regulates it, and supplies this regulated boost voltage to the commutating switch. The boost voltage delay circuit monitors the commutation switching action by rectifying voltage variations appearing across the inductor to charge an R-C circuit for several cycles of commutation switching action before the voltage across the R-C circuit rises sufficiently to turn on a transistor which enables the boost voltage circuit to supply boost voltage to the commutating switch. Commutation loss due to failure of the commutating switch to become reverse biased under applied boost voltage is thereby prevented.

Window detector circuit

Abstract: The circuit includes an MOS transistor for transmitting the applied voltage wave to the output signal terminal during the interval that applied voltage is between two voltage limits and circuit elements responsive to the applied voltage wave exceeding the higher of these limits for disabling the MOS transistor and for clamping the output signal terminal to a reference level such as ground.

Digital servo comprising means for controlling driving energy in response to droop

Abstract: Supplied with driving energy, a digital servo system drives a controlled member with inevitable droop and produces an alarm signal representing whether or not the droop is within a predetermined range. A control pulse generator produces control pulses when the droop is within the range. A reversible counter accumulates an instantaneous number of command pulses supplied to the system in compliance with the sign indicated by a direction command signal also supplied to the system. The control pulses, when produced, reduce the number towards zero. In compliance with the absolute value of the number, the counter adjusts the energy.

Voltage controlled bi-directional stable source apparatus

Abstract: A velocity error voltage in a VTR is derived by phase comparison of the off-tape horizontal sync pulses with reference sync pulses prior to a one horizontal line delay having a non-critical delay time in the signal path. The DC error voltage controls a ramp voltage which is added to the chrominance error detector voltage for control of a variable delay line in the signal path. The voltage controlled bi-directional current source circuit is particularly suitable in this environment for accurately converting the velocity error voltage to a stable current for charging a capacitor to provide the ramp correction voltage for control of the variable delay line.

Voltage generating circuit for a gas turbine fuel control system

Abstract: In a fuel control system for a gas turbine engine, a fuel flow limiting signal is obtained from the difference between a voltage proportional to turbine inlet temperature and a voltage produced by an ambient temperature modified speed reference circuit. In the latter circuit, a first differential comparator passes the greater of a voltage proportional to compressor speed and a first reference voltage. A second differential comparator passes to the circuit output the lowest of the output of the first differential comparator, a second reference voltage and a third reference voltage which varies with ambient air temperature.

Capacitive based voltage reducer and regulator

Abstract: A combined voltage reducer and regulator is provided for delivering a relatively low voltage, derived from a higher voltage source, to a load so as to maintain a relatively constant voltage at the load. The voltage reducer comprises a plurality of capacitors, diodes and selectively operated switches which, dependent upon the order of application of timing signals, operates in either one of two different modes to achieve different degrees of voltage reduction. The inherent nature of the capacitors provide a limited degree of voltage regulation. Supplementing this, in each mode of operation, a voltage regulator or regulating circuit is provided to provide a fine degree of voltage regulation between limits. When one limit is reached, the mode of operation of the voltage reducer is switched to allow the fine degree of regulation to take place in the other mode, the switching between modes providing a coarser degree of voltage regulation.

Voltage run-down circuit

Abstract: The voltage run-down circuit comprises first and second circuit branches connected in parallel and adapted to be connected between the input of a comparator in a photometric analysis system and a common conductor for the system. A capacitor which stores a reference voltage is situated in the first branch and a resistance is situated in the second branch. A resistance is also situated in the first branch in series with the capacitor to provide an initial step-down of the voltage decay of the reference voltage stored in the voltage run-down circuit when a test voltage from a photoresponsive device is applied to another input of the comparator and the capacitor is permitted to discharge, thereby to compensate for inadequate high frequency response in the comparator.

Pressure regulating valve

Abstract: The time responsiveness of a pressure regulating valve is increased by including a metering element mounted on the main valve element being movable therewith and relative thereto so as to respond to changes in pressure in the system independently of the main valve element Pressure droop can be adjusted independently of flow droop, thereby permitting optimum performance

Circuit arrangement for generating a stabilized direct voltage with superposition of a control voltage

Abstract: Integrated circuit for superposition of an AFC control voltage on a stabilized direct voltage for varactor diode tuning in radio or television receivers It features a voltage divider having a controlled current applied to it A circuit disables it when tuning

Circuit for the preferential starting of a stage of an electronic sequence having a holding circuit

Abstract: A circuit for the preferential starting of a stage of an electronic sequence having a holding circuit has two supply voltage sources of different potentials for driving the circuit, the voltage necessary for starting the preferred stage dropping across a component connected between a control electrode of a switching transistor setting the stage in operation and the potential connection common to the circuit, this component being connected in series with a voltage divider and a constant voltage element at the higher value voltage source, the tapping of the voltage divider being connected by a unidirectional component to the voltage source of lower potential and the loading of this voltage source, resulting only with the presence of the higher potential, being eliminated or considerably reduced when using the voltage of lower potential.

Voltage compensated phase shifting circuit

Abstract: A voltage compensated phase shifting circuit is provided through the employment of a pair of matched transistors having substantially identical electrical characteristics and to the bases of which there is applied a common voltage. The collector to emitter circuits of each of the transistors are supplied, respectively, with currents proportional to the average voltage input and to the instantaneous voltage input. By the proper scaling of the two currents, an output signal representative of a desired phase displacement is obtained which output is substantially independent of instantaneous variations in the input voltage.

Automatic Voltage Regulation of DC Shunt Generators

Abstract: In a dc shunt generator, as the load increases the terminal voltage falls, giving a drooping characteristic. The regulation of voltage involves the adjustment of field excitation. A simple method of voltage regulation by automatic adjustment of field excitation making use of transistor circuitry is discussed. The added advantage of this method is that by the simple adjustment of circuit parameters, the characteristics of a compound generator can be achieved. Experimental results prove the effectiveness of the method.

Clamp circuit for a color television receiver

Abstract: A clamping circuit which provides a first biasing voltage to a color signal transmission path when a video signal is received, and a second, lower biasing voltage when no signal is received. A transistor is periodically gated into conduction by a horizontal synchronizing pulse, charging a capacitor placed in shunt with one portion of a resistive voltage divider. The capacitor discharges through the voltage divider portion, increasing the voltage drop thereacross. The increased voltage drop causes the potential of other portions of the voltage divider to rise proportionately, increasing the biasing voltage applied to the color signal transmission path. When no video signal is received the horizontal synchronizing pulses cease and the transistor is disabled, causing the bias voltage provided by the voltage divider to fall to its quiescent level.

HV drive cct. for LV motor sets - has static inverter controlled by ignition and quenching ccts. controlled by voltage comparator

Abstract: The high voltage drive circuit for low voltage a.c. or d.c. motors has the input high voltage (e.g. 3 kV) rectifier output filtered and passed to the high voltage static inverter. The inverter output is coupled via a transformer to the motor. The transformer secondary voltage is monitored and compared with the voltage at the output of the filter. The comparator output is passed over a voltage regulator to an ignition stage and a quenching circuit, both for the thyristors in the static inverter. The static inverter output is coupled back to the quenching circuit. The circuit is relatively independent of the magnitude and type of input voltage.

Regulator circuit having a clamped regulating wave

Abstract: A circuit for providing a regulated a-c or d-c output voltage from an unregulated a-c input voltage. A series regulating network is disposed between the regulator input and the regulator output to support the difference between the unreglated input voltage and the regulated output voltage. A shunt regulating network is connected in shunt with the series regulating network to generate a plurality of regulating waves which, together with the input voltage, control the current through and voltage across the series regulating network. Output voltage sensing circuitry controls the phase angle between the input voltage and the regulating waves, as required, to establish and maintain the regulated output voltage.