126 results about "Filament current" patented technology

The invention discloses a filament current value calibration method and device for an X-ray tube, and the method comprises the steps: receiving a few of to-be-calibrated tube current values and to-be-calibrated tube voltage values; obtaining a preset filament current value according to the to-be-calibrated tube current values, the to-be-calibrated tube voltage values, and the relation among a preset tube current value, a preset tube voltage value and the filament current value; receiving a first actual tube current value, collected externally, of the X-ray tube under the action of the to-be-calibrated tube voltage values and the preset filament current value during exposure; judging the size relation between the absolute value of the difference, between a first actual tube current value and the to-be-calibrated tube current value, and a first preset difference value, and the size relation between the absolute value of the difference, between the first actual tube current value and the to-be-calibrated tube current value, and a second preset difference value; and enabling the preset filament current value to serve as a calibrated standard filament current value corresponding to the first actual tube current value and the to-be-calibrated tube voltage value when the absolute value is less than or equal to the first preset difference value. The method is small in number of exposure times, and does not cause the service life of the X-ray tube to be reduced.

An ion implanting apparatus is provided with a control apparatus 22 for controlling the filament current passing to the respective filaments 6 in accordance with the beam current IB measured by a plurality of beam current measuring instruments 18. The control apparatus 22 performs, at least once respectively, {circle around (1 the current value control routine which calculates average values of all beam current measured by the beam current measuring instruments 18, and increases and decreases the respective filament current IF such that the average value comes near to the set value, and {circle around (2 the uniformity control routine which groups the beam current measuring instruments 17 into the number of the filaments, seeks for a maximum value and the minimum value from all the measured values of the beam current IB, decides groups to which the maximum value and the minimum value belong, decreases the filament current IF passing to the filaments 6 corresponding to the maximum value, and increases the filament current IF passing to the filaments 6 corresponding to the minimum value.

The invention provides a control method for the frequency-conversion power supply circuit starting process of a magnetron. The method comprises the steps that s1) after electrification, a switch control signal is sent to a drive circuit in the initial minimal pulse width value and the initial switch frequency value, and at the same time, a sampling signal is output to a control module; s2) the pulse width of the switch control signal is increased gradually till the filament power of the magnetron reaches a preset basic power value for filament heating; s3) whether the anode current of the magnetron is increased and the increase amount are determined, the pulse width of the switch control signal is increased and the frequency of the switch control signal is reduced if the anode current is increased, and the pulse width and the frequency of the switch control signal are maintained if the anode current is not increased; and s4) whether the anode power of the magnetron reaches an oscillation-starting power threshold of the magnetron is determined, if the threshold is not reached, the s3) is returned to, and if the threshold is reached, the starting process is completed. The control method can be used to control the filament current during starting within the specification of the magnetron, and ensure that starting is completed in the standard prescribed time of the product.

The embodiment of the invention discloses a method for controlling filament current in a CT bulb tube. The method comprises the steps of detecting current tube current of the CT bulb tube and using the tube current as an mA feedback value; calculating the difference of an mA set value and the mA feedback value and using the difference as an error value; setting current filament current as a target current upper limit value if the error value is greater than a first error threshold value; setting the current filament current as a target current lower limit value if the error value is smaller than a second error threshold value, wherein the target current upper limit value is greater than the target current lower limit value, the first error threshold value is greater than 0, and the second error threshold value is smaller than 0. By means of the technical scheme, the change speed of actual tube current can rapidly follow the change of the mA set value, and accordingly quick adjustment of radiation dosage is achieved. In addition, the embodiment of the invention further provides a device for controlling the filament current in the CT bulb tube.

A microwave generation device includes: a magnetron having a cathode containing a filament and an anode containing a hollow resonator arranged to oppose to each other; a filament current measuring unit; and an application voltage measuring unit for measuring voltage applied to the filament. Based on the current and the voltage obtained by the current measuring unit and the voltage measuring unit, a resistance value calculation unit obtains a resistance value of the filament. A temperature calculation unit calculates the filament temperature from the resistance value and the resistance-temperature dependent characteristic. A filament power source is controlled by a power control unit so that the filament temperature is within a predetermined temperature range.

The invention relates to a device and a method for measuring satellite material surface electrostatic discharge pulse characteristics in the space plasma environment, and belongs to the field of measurement. The device comprises an electronic gun, a vacuum chamber, a vacuum pumping system, a grounded metal board, a reference pulse signal receiving antenna, arrayed pulse signal receiving antennas and a spectrometer. The method comprises the steps of placing satellite surface material samples into the vacuum chamber, start the vacuum pumping system, starting the electronic gun, regulating acceleration voltage and filament current of the electronic gun, conducting real-time monitoring on beams of the electronic gun by means of a Faraday cup, starting the spectrometer, respectively measuring frequency domains of discharge signals of the pulse signal receiving antennas of different positions, and conducting real-time monitoring on space distribution of discharge pulse radiation electromagnetic fields in an experiment process. An arc structure at the tail end of the grounded metal board resolves the problem of edge reflection of the radiation fields, and measurement of the space distribution of the radiation fields is conducted through the antennas.

The invention relates to a dual-bulb tube high-voltage oil tank arranged in an X-ray high-voltage generator. The high-voltage oil tank is provided with a voltage-multiplying rectification circuit, a boosting transformer, a filament transformer and a high-voltage switching device, wherein a primary winding of the boosting transformer is connected with an inversion part of the high-voltage generator; the voltage output by the inversion part is boosted and output to the voltage-multiplying rectification circuit through the primary winding; the high-voltage direct-current voltage output by the voltage-multiplying rectification circuit is transmitted to a first high-voltage bulb tube and a second high-voltage bulb tube through the high-voltage switching device. The invention ensures participation in high-voltage generator resonance, adopts voltage-multiplying rectification circuit, has a high resonance frequency of 80-250kHz and little output high voltage ripple, improves the quality of X ray emitted by the bulb tube, ensures that the filament current frequency output by the dual-bulb tube high-voltage oil tank is 40kHz so as to improve the definition of perspective and exposure images, is small in size to realize effective isolation between strong current and weak current.

The invention provides a filament current and tube current dual-closed loop control device for an X-ray machine, belonging to the technical field of medical apparatus and instruments, and structurally consisting of a tube current sampling unit, a tube current reference unit, a filament current reference unit, a tube current closed-loop control unit, an addition unit, and a filament current closed-ring control unit. According to the technical points, a tube current is dynamically adjusted by using the tube current closed-loop control unit, and a filament current reference and tube current dual-closed loop is controlled by the addition unit. The filament current and tube current dual-closed loop control device provided by the invention has the advantages as follows: not only can the tube current stabilize the filament current, but also the filament current is stabilized again through a tube current feedback signal, so that the tube current and the filament current obtain higher precision and stability through dual-path closed ring. Particularly, the filament current and tube current dual-closed loop control device for the X-ray machine has very obvious effects in large-current photograph, continuous fluoroscopy and pulse fluoroscopy.

The invention relates to a method for controlling currents of an X ray tube and a device for controlling the currents of the X ray tube by implementing the control method. In the method and the device, an analog option switch gates a filament current sampling unit or a tube current sampling unit and feeds back to a gain control unit, so that two closed-loop gain control loops are formed. Time-shared control is performed on the two closed-loop gain control loops, namely time-shared gain control is performed on filament currents and tube currents. Therefore, multiple-loop time-shared control can be performed on the currents of the X ray tube, the filament currents can be rapidly improved into currents required by proximity exposure, and more precise tube currents can be obtained after normal work, so that the X ray tube is practical and convenient and has high stability.

The disclosure relates to a laminar evaporator, comprising a laminar electrical resistance heating element for pulse heating and evaporation of an inhalationally receivable material distributed or distributable on the heating element surface by means of an electric heating current flowing or flowable in a laminar manner with at least two electrical contacts and/or poles (2, 3) for introducing the filament current into the resistance heating element, where the resistance heating element has at least one slot-shaped recess (5) constricting the lines of flux (4) of the original electric field forming or formable between the poles (2, 3) and is superficially bonded with an open-celled porous structure holding or capable of holding the material.

The invention provides a preheating method and circuit of an X-ray tube lamp filament of CT equipment. The preheating method comprises the following steps that setting of tube voltages, tube currents and a paying-off instruction are received, preheating time is calculated, and a lamp filament preheating current value is determined according to the tube voltages, the tube currents and the preheating time; a lamp filament current preheating instruction is sent to a high voltage generator of an X-ray tube according to the preheating time and the lamp filament preheating current value; the lamp filament is preheated on the high voltage generator according to the preheating time and the lamp filament preheating current value.

A microcomputer control debugging method for high-voltage generator of x ray machine has its hardware structure composed of control circuit, inverse transformation circuit, high-voltage transformer and ball tube, and their connections are the control circuit output to be connected with the input end of high-voltage transformer through D/A converter, the output of the high-voltage transformer to the connected with the input ends of ball tube varying voltage and lamp filament current, and the output of the high-voltage transformer to be feedback to the input end of the control circuit through A/D converter; and the hardware part uses storage chip (RAM) with lithium cell to store training management data in the storage chip in advance and carries on the debugging for ball tube in the high-voltage generator of X ray machine by utilizing the storage chip.

A temperature control method for a heating apparatus including a chamber which can be evacuated and has a conductive portion, a filament which is positioned in the chamber, a first power supply which supplies a current to the filament, a second power supply which applies, to the filament, a voltage for acceleration to the chamber, an ammeter which measures a current of the filament, and a voltmeter which measures the acceleration voltage, the method comprises a first step of evacuating an interior of the chamber; a second step of supplying the filament current from the first power supply to the filament after the first step; a third step of applying the acceleration voltage to the filament after the second step; and a fourth step of controlling the acceleration voltage to keep a surface temperature of the chamber to be lower than a temperature of the filament after the third step while keeping constant the filament current from the first power supply.

An indirectly heated cathode ion source includes an extraction current sensor for sensing ion current extracted from the arc chamber and an ion source controller for controlling the filament power supply, the bias power supply and/or the arc power supply. The ion source controller may compare the sensed extraction current with a reference extraction current and determine an error value based on the difference between the sensed extraction current and the reference extraction current. The power supplies of the indirectly heated cathode ion source are controlled to minimize the error value, thus maintaining a substantially constant extraction current. The ion source controller utilizes a control algorithm, for example a closed feedback loop, to control the power supplies in response to the error value. In a first control algorithm, the bias current IB supplied by the bias power supply is varied so as to control the extraction current IE. Further according to the first control algorithm, the filament current IF and the arc voltage VA are maintained constant. According to a second control algorithm, the filament current IF is varied so as to control the extraction current IE. Further according to the second control algorithm, the bias current IB and the arc voltage VA are maintained constant.

The invention provides a control method and apparatus of filament currents. The method comprises the following steps: obtaining voltage input values, and calculating voltage change parameters by use of the voltage input values; obtaining control parameter correction values by use of the voltage change parameters; correcting control parameters by use of the control parameter correction values; obtaining voltage output values by use of the control parameters after correction; and controlling the filament currents by use of the voltage output values. According to the technical scheme provided by the invention, the corrected control parameters can meet control requirements, a PID controller can better control the filament currents, the filament currents maintain rapid, stable, accurate and reliable at a filament preparation stage and a filament exposure stage, the real-time performance and the anti-interference capability are quite high, the dynamic and static performance is good, static and dynamic performance of tube currents is improved accordingly, and the image quality is improved.

An oxygen detection method, includes: preparing a grid, an ion collector, and a filament in which an oxide are formed on a surface of metal; controlling a filament current flowing to the filament so that an emission current becomes constant; discharging thermionic electrons which are caused by heat generation by applying the filament current, and generating ions by ionizing a gas; capturing the ions with the ion collector; and detecting oxygen being present in a vacuum processing chamber by measuring a filament current value.

The invention discloses a power line carrier based distributed control system for magnetron power sources. The system includes an upper computer and a magnetron management module, wherein the upper computer is used for monitoring working states of the magnetron power sources and performing remote control; and the magnetron management module is in communication with the upper computer and is used for supervisory control and for collecting temperature, humidity, anode current, cathode current, filament voltage, filament current and electromagnet current of the magnetrons. According to the invention, low-voltage broadband power line carrier technology is utilized and the working frequency range is 1-40 MHz, so that low-frequency interference is avoided effectively and reliable data transmission with a transmission range of 200 to 300 m can be realized. The system can meet power control demands of magnetrons in a single microwave device. No separate wiring is needed and the system has advantages of being easy in execution and adjustment, comparatively small in operation maintenance load, good in data security and large in bandwidth.

The invention discloses a filament correction method, a device and an electronic device, wherein, the method comprises the steps of obtaining a current filament current; Obtaining the current tube current by using the current filament current; Extracting the current correction step size and the last tube current; Adjusting the next correction step length according to the current tube current, thecurrent correction step length and the last tube current; Calculating a next filament current based on the current filament current and the next correction step. The next calibration step is adjustedaccording to the change of the current. When the change of the current is larger and larger, the calibration step is automatically reduced, and the precision of the current is improved. In addition, the accuracy of the tube current can be ensured with the least number of exposure times by the filament correction method with variable step size, and the service life of the ray tube can be prolonged.