Abstract: A programmable DC-TO-AC voltage converter for converting a DC voltage signal provided across two DC voltage terminals to an AC voltage signal having predetermined characteristics. The system includes an AC voltage terminal; a first switch connected between the AC voltage terminal and one of the DC voltage terminals; a second switch connected between the AC voltage terminal and the other of the DC voltage terminals; and a bistable switching circuit coupled to the first and second switches for operating the first and second switches to alternatively connect either the one DC voltage terminal or the other DC voltage terminal to the AC voltage terminal in an alternating high frequency sequence to provide a high frequency pulsed voltage signal at the AC voltage terminal. The bistable switching circuit sequentially provides a pulse-width-modulated control signal to operate the first and second switches at a predetermined high frequency; and varies the duty cycle of the control signal pulses at a predetermined low frequency in accordance with a predetermined waveform pattern at the predetermined low frequency to thereby vary the duty cycle of the high frequency pulsed voltage signal at the AC voltage terminal in accordance with the predetermined waveform pattern at the predetermined low frequency. The system also includes a low pass filter connected to the AC voltage terminal for providing an AC voltage output signal at the predetermined low frequency and having the predetermined waveform, such as a 60 Hz sine wave.

Abstract: A controller of the voltage, a motor for single phase and three-phase motors of, used to control the supply voltage of the motor way to reduce the power when the engine is not fully supported The monophase device (10) comprises a soft start unit of (31) and a failure detecting unit (32) The three-phase device (200) comprises a soft start unit of (241), a failure detecting unit (242), and provides further control of the voltage of the motor by allowing changes only to the half-cycle positive motor voltage The three-phase device (200) also ensures a continuous passage for the negative motor currents The three-phase device (200) also provides a logical basis for the logic circuit The three-phase device (200) can be used with three-phase motors (206) that do not have an easily accessible branch on a fourth conductive internal connection earth

Abstract: A new ac voltage regulator is proposed which employs thyristors as switching elements in the secondary of a power autotransformer.

Abstract: A bank of high power quartz iodine lamps is regulated so that changes in light output from the lamps for a 40 volt change in AC line voltage is reduced from 132% to 10%. To accomplish this, a regulating pulse width modulator is synchronized to the AC line so that pulse width modulated pulses are developed the trailing edge of which is coincident with the zero crossover points of the AC line voltage. The variable leading edge of these width modulated pulses is employed to control the firing point of semiconductor switching devices in series with the lamps, the average voltage across the lamps being sensed and employed by the regulating pulse width modulator to vary the width of the pulses in the correct direction to maintain the lamp voltage constant despite large changes in line voltage.

Abstract: The primary winding of a high leakage inductance transformer is coupled to a source of alternating input voltage to develop alternating polarity output voltages across tightly coupled secondary windings, including a high voltage winding of the transformer. Various DC supply voltages, including the ultor voltage, are derived from the secondary winding output voltages. To regulate the secondary winding output voltages, a ferroresonant circuit comprising a capacitor and a saturable reactor is coupled as a load circuit to one of the transformer secondary windings. When the saturable reactor magnetically saturates during each half cycle of the alternating polarity output voltage, a circulating current is generated and flows between the saturable reactor and the capacitor. To enhance the power supply efficiency and reduce the temperature rise within the magnetizable core of the saturable reactor, the parameters of the transformer and ferroresonant load circuit are selected so as to generate a relatively low amplitude circulating current. To improve output voltage regulation when a low amplitude circulating current is developed, a compensating drive winding is provided that is magnetically tightly coupled with the primary winding of the high leakage transformer. The compensating drive winding is coupled in series with the saturable reactor winding across the capacitor and polarized relative to the capacitor coupled transformer secondary so as to oppose the tendency of the output voltage amplitude or half-cycle volt-second area to vary with variations in input voltage amplitude.

Abstract: The operation of the major components used for controlling the phase and field level of the PEP RF cavities is described. The control electronics of one RF station is composed of several control loops: each cavity has a tuners' servo loop which maintains the frequency constant and also keeps the fields of each cavity balanced; the total gap voltage developed by a pair of cavities is regulated by a gap voltage controller; finally, the phase variation along the amplification chain, the klystron and the cavities are compensated by a phase lock loop. The design criteria of each loop are set forth and the circuit implementation and test results are presented.

Abstract: The method is for testing and monitoring inductive direct voltage loads for functioning and operating condition and is esp. applicable to domestic equipment switched by program control devices via amplifiers, pref. inverters. It enables the associated switching and control elements and cabling to be tested as well as the operating equipment. The control voltage which determines the operating mode, and which is applied to the load, is transiently passed by or cut off by the switching inverters (3,4). The resulting pulse shaped load voltage change, which is caused by the bad power variation associated with the switching process, is measured for height and, where required, for pulse duration. The transient control voltage variation is performed by an electronic control unit, e.g. a microcomputer. The signal voltage change is evaluated in the same unit.

Abstract: In the case of a circuit arrangement for voltage and current stabilisation of a high-voltage generator (10) for copiers which operate by means of a corona discharge, a comparator stage (11) is provided in order to implement an automatic transition between voltage and current stabilisation and for short-circuit current limiting, which comparator stage (11) compares a reference voltage (Uref) with a voltage (U1) derived from the output voltage (UA) of the high-voltage generator (10) and with a voltage (U2) derived from the output current (IA) of the high-voltage generator (10), in such a manner that, if the voltage (U1) derived from the output voltage (UA) or the voltage (U2) derived from the output current (IA) exceeds the reference voltage (Uref), it supplies an output signal to control an input voltage (UE) of the high-voltage generator (10) in the sense of stabilising the output voltage (UA) and the output current (IA).

Abstract: The primary winding of a high leakage transformer is coupled to a source of alternating input voltage for developing an alternating supply voltage across a secondary winding of the transformer. A self-regulating, ferroresonant load circuit includes a saturable reactor that has a first winding coupled to the transformer secondary winding for regulating the supply voltage. A high voltage winding of the transformer steps up the supply voltage. The stepped up voltage is rectified to produce an ultor accelerating potential for a color picture tube of a television receiver. If the saturable reactor first winding is disconnected from the transformer secondary winding, the supply voltage and ultor accelerating potential undesirably tend to increase in amplitude. To protect against the emission of excessive X-radiation from the phosphor screen of the picture tube in such an event, the heater filaments of the picture tube cathode electrodes are energized by a second winding of the saturable reactor. If the saturable reactor first winding becomes disconnected, heater energization is removed, producing a blank picture screen.

Abstract: The A/D converter has a compensation voltage comprising an ac voltage produced by keying. The average value of the ac voltage is determined by the duty factor of the keying. The compensation voltage is added to the analog voltage and the dc component is filtered out. If the dc voltage component differs from zero, the duty factor of the compensation voltage is changed such that the dc voltage component tends to zero. The duty factor is a digital measure of the analog signal. The compensation voltage may consist of several ac voltages produced by keying and having different weightings.

Abstract: PURPOSE: To decrease the thermal loss of an output amplifying element, by controlling the voltage of a circuit power supply of an electric power amplifier in accordance with the level of the signal and supplying the controlled voltage as the voltage of the output amplifying element. CONSTITUTION: The DC voltage supplied from outside is converted into the square wave-shape AC voltage by an inverter 1 and boosted by a pulse transformer 2. The middle point (o) of the 2nd winding of the transformer 2 serves as an earth line. The voltages at both ends (a) and (a') of the earth line are fed to an integral network 4 via the saturable reactors 3 and 3' and then a rectifying circuit consisting of the diodes D 1 , D 2 and D 1 ', D 2 '. The positive/negative outputs (d) and (d') which are integrated and then converted into the DC voltage are used as the power supply voltages of an electric power amplifying stage 5. In such way, an AC voltage generating means that generates the square wave- shape AC voltage is provided along with a pulse duration modulating means that varies the pulse duration of the AC voltage in accordance with the output of an amplifier and an integrating means that integrates the pulse duration modulated output. Then the integral output is used to the power supply voltage of an amplifier. COPYRIGHT: (C)1983,JPO&Japio

Abstract: A power factor controller for a motor is of the type having a bidirectional triode thyristor and a circuit for sensing the voltage across the thyristor to determine the time by which the current lags the line voltage and for generating a signal voltage across an integrating capacitor that is inversely proportional to the current lag time. In addition, a voltage ramp generator produces a ramp voltage having a slope that increases as the lag time decreases. A sum of the signal voltage and ramp voltage is applied to the input of a threshold detector that triggers firing of the thyristor when a predetermined threshold is reached. The entire controller employs only five integrated switches or gates and two individual transistors, and power dissipation, size and cost are thereby minimized.

Abstract: An analogue voltage-to-digital converter has a voltage divider (11) with a plurality of steps (13) for comparison with the unknown voltage and in addition provides interpolation between steps to improve the accuracy Interpolation is effected by adding a ramp voltage from a generator (22) to the unknown, the ramp voltage ramping through a magnitude equivalent to at least one step With one tap (13) on the voltage divider (11) selected, comparison of the unknown plus ramp voltage is effected in a comparator (14) successively as the voltage ramps By noting when the combined voltage reaches the level of one of the reference voltages and by counting in a microprocessor (16) the number of comparisons made from the time when the ramp voltage is at a predetermined magnitude and comparing this with the time taken to ramp through one or a plurality of whole steps, determination can be made of the magnitude of the unknown voltage to a fraction of a step

Abstract: PURPOSE:To exactly operate a cooling fan for long term by measuring the temperature of an object to be cooled, varying the operating voltage of the cooling fan in accordance with the temperature thereby controlling the rotating speed of the cooling fan, thereby preventing the deterioration of the cooling system CONSTITUTION:A thermocouple is employed in a temperature detector 5, the detector 5 is mounted on an object apparatus 1 to be cooled, the temperature of the apparatus 1 is measured, and a temperature signal voltage 7 proportional to the temperature is transmitted to a voltage controller 6 The voltage controller 6 thus controls the signal voltage 3 supplied from the apparatus 1 in accordance with the signal voltage 7 and supplies the signal voltage 3 to the cooling fan 2 as the operating voltage 8 for the cooling fan As the operating voltage 8 is varied, the rotating speed of the cooling fan 2 will change Since the rotating speed of the cooling fan 2 is varied in accordance with the temperature change of the apparatus 1, the deteriorating period of the cooling fan 2 can be prolonged and the efficient cooling can be conducted

Abstract: PURPOSE:To enhance the operating efficiency of a rotary electric machine by allowing an excessive maximum allowable current when it is within a predetermined time even if a field current exceeds the maximum allowable current and by containing the primary delay of the field current in a feedback loop. CONSTITUTION:When a deviation signal 7a between a field current 6a and the maximum allowable current 8a exceeds an allowable value V0, a time limiting circuit 17 is operated so that its contact 17a is opened. Thus, an integrator 15 will integrate the deviation signal 7a at a time constant responsive to the value of the deviation signal 7a. When the output signal from the integrator 15 exceeds the voltage of the signal 24a, time limiting circuits 25, 25' will operate to close contacts 25a, 25a' so that the deviation signal 7a is applied through a primary delay circuit 16 to an automatic voltage controller 3. In this manner, the operating efficiency of the generator 1 can be enhanced.

Abstract: PURPOSE:To improve the starting property of a timepiece powered by a lithium battery and lengthen the lifetime of the battery, by detecting in terms of a frequency division output whether there is an oscillation state or not, control a switch circuit for selecting a lithium battery voltage reduction circuit. CONSTITUTION:At the moment of the connection of a lithium battery 1 to an electronic circuit, an oscillation circuit 2 does not act and a frequency divider circuit 3 generates no frequency division output. As a result, the level of the output of the inverter 8d of an oscillation detection circuit 8 becomes high, the transmission gate 9b of a switch circuit 9 is opened, a high voltage is selected from a lithium battery 1 through a transmission gate 9a and applied to the circuits 2, 3, a timepiece counter 3, etc. so that a timepiece goes with good rising into an oscillation stage. The oscillation is detected in the same manner on the basis of a frequency division output so that the voltage of the battery 1 lowered by a voltage reduction circuit 5 is applied to the circuits 2, 3, a counter 4, etc. through a circuit 9. The consumption of the lithium battery is suppressed because of low power driving. This results in lengthening the lifetime of the lithium battery.

Abstract: The controller produces a constant output voltage from a constant input current where the input and output voltages are almost identical. A series and a parallel voltage controller are connected one after the other. The parallel controller produces a constant output voltage defined by a voltage divider Current and by the slightly higher constant voltage from the series controller. It is intended for telephone systems current supplies and implemented using integrated precision regulates. A resistor lies between the series controller output and the parallel controller input. This resistor along with the constant output voltages from the controllers ensures a constant input current that is larger than the max. load current taken from the parallel controller.

Abstract: An ac voltage regulator capable of operating from the mains with excellent regulation and considerable power-handling capacity is achieved by means of a negative-feedback configuration that aims at high efficiency. Practical efficiencies as high as 95 percent and regulation as low as 0.02 percent are easily achieved with a little extra circuitry. To illustrate the scheme, a model ac regulator was built to deliver 90-W output power in a 137-? resistive load at V o = 111 V rms at 50 Hz from an input source fluctuating between V in = 115 to 140 V rms. The overall efficiency when the input is at the lower limit is 96.5 percent and the efficiency drops to 79.3 percent when the input is on the higher limit giving an average efficiency of 88 percent. The output voltage varies only by 0.1 V rms for a 25-V input fluctuation thus giving a regulation of 0.4 percent. In addition to the many applications as voltage stabilizers in television sets, refrigerators, and small motors, etc., this scheme is most suited as a general control element in many systems as temperature controller and speed controller, etc.

Abstract: PURPOSE:To control the voltage of an X-ray tube in an accurate state further with quick speed of response, by controlling conduction of a transistor only in a period of phase not more than a prescribed value corresponding to preset tube voltage for an AC power source. CONSTITUTION:A pulse unit 10 and transistor unit 8 are coupled by a photocoupler 11. The input side of a transformer 10A is connected to a power source side of the transistor unit 8. Output from the transformer 10A is full-wave rectified through a diode bridge 10B and input to the inversion terminal of a comparator 10C. Constant DC voltage from a variable resistor 10D is input to a noninversion side input terminal of the comparator 10C. Output of the comparator 10C is connected to a photodiode 11A of the photocoupler 11 through a current limiting resistor 10E, and a transistor 8B is driven by a phototransistor 11B. The transistor 8B is conductibly controlled only in a period of phase not more than a prescribed value of AC power source voltage.

Abstract: The device for rotating machine current regulator has a voltage transformer (5) with the secondary connected across the output of the current regulator (4), and a previously calculated additional voltage applied across the primary for each respective phase (R,S,T). The necessary commutating voltages for the thyristors (4.1-4.6) of the current regulator are constantly available. An AC regulator (12) is connected to each primary winding of the voltage transformer (5), each with a centre-tap coupled to one of the other primary windings or to a diode rectifier. The current regulator is used for synchronous machines, asynchronous slip-ring rotor machines and asynchronous short-circuit rotor machines.

Abstract: A new type of voltage regulator whose principle of operation is similar to that of a conventional saturable reactor is presented. It is shown that the stored magnetic field energy can be used to produce the required DC excitation with controllable level without using an auxiliary DC power source. Semiconductor switches in conjunction with standard three-limb magnetic circuits are used. A wide range of output voltage control is achieved and both lagging and leading power-factor operation is possible.

Abstract: PURPOSE: To inexpensively perform a highly accurate control, by giving a closed loop function to the voltage controller of the titled digital controlling device by constituting the voltage controller with a combination of a cancelling circuit, a frequency converter and a reversible counter. CONSTITUTION: A voltag controller 7B of a thyristor Leonard speed controlling device inputs pulse trains 15 which are obtaind by converting analog voltage signals 14 from the main circuit composed of an AC power source 1, an SCR 2, and a DC motor 3 into frequencies proportional to the voltage value at a voltage-frequency converter 11B, and digital value signals 13 from a microprocessor 12 containing a speed controller 5A and an electric current controller. The pulse train 15 is inputted into a pulse cancelling circuit 21 of the controller 7B and the signal 13 is converted into a pulse train 18 having a frequency proportional to the signal value by a converter 17, and both pulse trains 15 and 18 are inputted into the circuit 21. The circuit 21 inputs a pulse train 20 which is obtained by converting the output pulse 16 of a reversible counter circuit 22 into a frequency proportional to the pulse value by a converter 19, and outputs a differential pulse train 23 obtained by cancelling the pulse trains 20 and 15 set to down and the pulse train 18 set to up into the circuit 22, and thus a closed loop is constituted. COPYRIGHT: (C)1982,JPO&Japio