摘要:
The disclosure relates to an X-ray photographic apparatus which can prevent the overshoot of the tube current, which is apt to generate at the start of X-ray radiation. The apparatus comprises an integration capacitor which is charged by the preset preheating level setting voltage during the preheating period, an integration circuit which integrates the difference between the reference voltage and the detection voltage corresponding to the X-ray tube current during the X-ray radiation and a filament heating current control circuit driven by said integration circuit.
摘要:
The disclosure relates to a dental radiographic apparatus for photographing the entire jaws having a rotary arm including an X-ray generator disposed in an opposed relation with an X-ray film feed means. The apparatus includes a means for detecting electrically the shape and characteristics of an object through the position of the rotary arm rotated and a means for automatically controlling the rotation speed of the arm and the feed speed of an X-ray film in response to the detection signal generated by the electrical detection means, whereby it is intended to provide a clear and sharp X-ray photographic image free from distortion, uniform in density and optional in rate of enlargement.
摘要:
This disclosure relates to the improvement of a tomograph for photographing the entire jaws which is designed to make an X-ray photograph of a curved plane section of an object by changing the rotating output of a motor for driving a rotary arm by using an eccentric cam means to control a film feed speed by the rotary output thus change. This apparatus includes a tachogenerator for converting the rotating output of the rotary arm driving motor into an electric output, a voltage shunting means for shunting the output of the tachogenerator to three paths, a reference point correction circuit and a changeover resistance means, and is capable of providing a clear X-ray photograph of a patient in the range of adults to children without necessity to change the eccentric cams nor the position of the patient.
摘要:
The disclosure relates to a gate driving circuit for a depletion type, static induction transistor, including a capacitor coupled between the emitters of complementary-connected NPN and PNP transistors and the SIT gate, high value resistor parallel-connected to a series connection of a diode and a resistor between the SIT gate, and a negative gate voltage source.
摘要:
This device feeds back an output proportional to the electric current flowing through an X-ray tube to a filament current controlling means, reads out a difference between the increase and decrease in the current of the X-ray tube made by the effect of charge on the wall of the X-ray tube, and constantly stabilizes the current in the tube at the optimum value by increasing and decreasing a filament current in response to the difference read out.
摘要:
This disclosure relates to a DC high voltage generator disposed on the base which is adapted to freely move into and out of a casing and on which a high voltage transformer circuit is disposed. The transformer circuit comprises a variable magnetic leak transformer and capacitor type multiple boosting circuits disposed separately on the right and left sides of the transformer. The high voltage generator is compact, easy of maintenance and inspection and is excellent in insulating countermeasures and in efficiency.
摘要:
This disclosure relates to a system for supplying a stable DC high voltage to a load by resonantly driving a high voltage transforming circuit comprising a VLT and a capacitor type multiple boosting circuit. The system includes a VLT, a capacitor type multiple boosting circuit and a pulse-amplitude feedback control circuit designed to detect supply voltage to load, to compare the detected voltage with reference voltage and to control the voltage of the control winding of VLT by using the deviation produced by the comparison as a control signal.
摘要:
The disclosure relates to an occlusion pressure sensor of the construction in which pressure sensitive block changing in electric characteristic under external pressure are arranged in multiple rows. The occlusion pressure sensor is designed to detect an electric signal responsive to occlusion pressure from the pressure sensitive blocks by successively and electrically scanning the blocks in the state of a patient engaging his teeth.
摘要:
A driving circuit for ultrasonic tools which uses a piezoelectric transducer to convert ultrasonic electric signals into ultrasonic mechanical vibrations including a voltage-controlled oscillator which produces an output signal at a frequency that is proportional to an input voltage, a power amplifier stage having its input coupled to the output of the voltage-controlled oscillator, the power amplifier stage including an output transformer which couples the output of the power amplifier stage to the piezoelectric transducer, the power output transformer further acting as both an insulating transformer and a boosting transformer for the driving circuit and a feedback transformer coupled in series with the secondary side of the output transformer and the piezoelectric transducer, the feedback transformer having a secondary side through which a current flows which is proportional to the current flowing through the piezoelectric transducer, a phase comparitor which detects the phase difference between two signals applied to two inputs of the phase comparitor, the two inputs being respectively coupled to the output signal of the voltage controlling oscillator and the secondary side of the feedback transformer and a low pass filter which blocks high frequency components to pass therethrough connected between an output of the phase comparitor and the input of the voltage controlled oscillator.
摘要:
The disclosure relates to a system for aerially transmitting an ultrasonic view of a vibration mode, small in angle of direction, in a clear state and to a transmitter and a receiver used in the system. According to the system, an ultrasonic pulse can be used for distance measurement, control and other signal means even at relatively short distance.