JPS62283600A - Operating voltage control circuit for roentgen ray device - Google Patents

Abstract

PURPOSE:To make it unnecessary to provide a transformer exclusively for preheating, to realize a compact and lightweight size, and to prevent a hazard from the transient current, by applying a constant bulb voltage after diverting the current of a high voltage transformer to reduce the transient voltage. CONSTITUTION:An operating voltage converting circuit 5 is furnished on the primary coil side of a high voltage transformer 1 to preheat in a specific time at a voltage suitable to preheat an X-ray bulb 3, and after that, a specific high voltage is applied. At the same time, a transient current diverting circuit 6 is connected parallel to the primary ciol side of the transformer 1 to divert a transient current to reduce the transient voltage produced at the tubular bulb 3 when a high voltage is applied to the transformer 1 by converting the circuit 5. Therefore, it is not uecessary to provide a transformer exclusive to preheat the tubular bulb 3, the whole device can be made compact and light- weight, and an electrical hazard by the transient current can be prevented.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application This application relates to an operating voltage control circuit in an X-ray machine.

BACKGROUND TECHNOLOGY AND PROBLEMS Conventionally, medical X-ray equipment has generally been configured to first preheat the filament of an X-ray tube and then apply a tube voltage to the X-ray tube by operating a hand switch. ing.

However, the above configuration requires a dedicated transformer for preheating the filament, and has the disadvantage that the entire device becomes large, heavy, and expensive.

Therefore, in order to reduce the cost and weight of simple X-ray equipment, a method is adopted in which tube voltage is directly applied by operating a hand switch without preheating the filament. X
There was a risk that a high voltage higher than the rated voltage would be applied to the ray tube, reducing the lifespan of the X-ray tube.

Purpose, Examples, and Effects Therefore, in the present application, a low voltage suitable for preheating the X-ray tube is first applied to the X-ray tube by an operation switch on the primary side of the high-voltage transformer in an X-ray apparatus, and then, after preheating, a low voltage suitable for preheating the X-ray tube is applied to the high-voltage transformer. A specified direct voltage is applied to reduce the transient voltage that occurs in the X-ray tube.

In order to do so, the current flowing through the high-voltage transformer is transiently shunted, and then the shunt is stopped, and the appropriate voltage for xvA irradiation is applied to the X-ray tube, thereby solving the above-mentioned inconvenience. It is.

Below, Figure 6, which describes the embodiment of the present application in detail together with the drawings, shows an operating circuit diagram of the X-ray apparatus of the present application. ) is a high-voltage transformer that applies high voltages to the anonide and filament, respectively, and a normally open switch (4) and an operating power switching circuit (5) are connected in series to the negative side of this high-voltage transformer (1). Current shunt circuits (6) are connected in parallel. The operating voltage switching circuit (5) is made up of a parallel circuit of a voltage drop resistor R2 and a first thyristor T H+ controlled by a first gate circuit (13), which will be described later, and the transient current shunting circuit (6). ) is a second gate circuit (14) controlled by a load resistor R2 and a second gate circuit (14), which will be described later.
It consists of a series circuit with a thyristor T Ht. (7) is a rectifier circuit (9) on the secondary side of the down-down transformer (8) connected to the output side of the variable tube voltage regulator (2).
and a smoothing capacitor C1 are connected to each other, and a relay switching circuit (10) and a delay circuit (11) are connected to each other via an operation switch SW2 between both terminals thereof.
This delay circuit (11) is connected in sequence to a timer circuit (12) which operates for a required period of time set by a trigger pulse. Further, one terminal of the DC ta circuit (7) is connected to the operation switch SW! a first thyristor TH of the operating voltage switching circuit (5) via a first thyristor TH;
a gate circuit (13); and a second gate circuit (1) that controls the second thyristor TH2 of the transient current shunt circuit (6).
4), and the other end thereof is connected to the other terminal of the DC power supply circuit (7) via a switching transistor Tr that becomes conductive upon receiving the output of the timer circuit (12). The relay switching circuit (
10) connects the delay circuit (11) to the relay coil (15).
) a transistor Trz that becomes conductive upon receiving a signal from the
The first gate circuit (13) consists of a parallel circuit connected in series with a transistor Tr that receives the output of the timer circuit (12) and becomes conductive, and the first gate circuit (13) is formed of a light emitting diode or the like that is generated when the transistor Tr+ becomes conductive. and a first light receiving element (16) that receives light from the first light emitting element 4 and applies a gate signal to the gate of the first thyristor TH. A second gate circuit (14) is a second gate circuit (14) comprising a light emitting diode, a light emitting diode, etc., which emits light when the transistor Tr is conductive.
Light emitting element Riyo and this first light receiving element D! The second thyristor TH! a first element section (17) that applies a gate signal to the gate of
14) a, a second element section (14) having a resistor R4 and a capacitor Ct that control the operation of the first element section (14) a via a transistor T r a parallel to the second light emitting element D2; It is composed of b.

Therefore, when performing X-ray imaging, first close the main switch SWI, and then turn on the operation switch SW, which variably operates the tube voltage variable regulator (2) to set the tube voltage to the required voltage. 2ft 'K [DC voltage from circuit (7) is applied to delay circuit (11), timer circuit (12), relay switching circuit (10) and first
．． The voltage is applied to the second gate circuits (13) and (14), respectively. Then, a voltage is applied to the base of the first transistor Trt of the relay switching circuit (10) through the delay circuit (11) connected in parallel to the DC power supply circuit (7), and the transistor Trz becomes conductive, causing the relay coil ( 15)
Current flows through the relay switch (4), which closes the AC voltage set by the variable tube voltage regulator (2) and supplies it to the high voltage transformer (1) via the resistor R1 of the operating voltage switching circuit (5). A voltage lower than the voltage drop caused by the resistor R, that is, a voltage suitable for preheating the filament, is applied to the X-ray tube (3) via the high voltage transformer (1). After the time required for proper preheating of the filament set by the delay circuit (11), a trigger signal is output from the delay circuit (11), which is input to the timer circuit (12). A voltage is applied to the bases of the switching transistor Tr+ and the second transistor Tr2 of the relay switching circuit (1o) for a predetermined period of time required for X-ray irradiation, and the transistors Tr+ and Tri4* are rendered conductive. Then, the relay coil (15
) is self-maintained until the timer circuit (12) stops operating, and DC voltage is applied to the first and second gate circuits () by conduction of the transistor Tr1.
Each of the light emitting elements 13) and (14) and D2 are energized and emit light. Then, the light emission from the first light receiving element DI causes the first thyristor TH of the operating voltage switching circuit (5) to be activated via the first light receiving element (16), and the light emission from the first light receiving element D2 causes the second light receiving element (17) to be activated. ) through the transient t
The second thyristors TH□ of the 2it shunt circuit (6) are conductive, and the current from the tube voltage variable regulator (2) is passed through the first and second thyristors TH+ and THf to the high voltage transformer (1). and a transient current shunt circuit (6), the current equivalent to reducing the transient voltage flows through the shunt circuit (6), and the X-ray tube (3) receives a normal tube voltage of, for example, 60 KVP. applied. On the other hand, the capacitor C2 of the second gate circuit (14), which has become energized due to the conduction of the transistor Tr+, is charged in parallel with the second light emitting element Riyo, corresponding to the time constant of the second element part (14) b. transistor T
The base potential of ra becomes high, the transistor Tr4 becomes conductive, and the first light receiving element Dt is short-circuited several seconds after the current equivalent to reducing the transient voltage disappears.

Therefore, the second thyristor TH, is turned OFF, so the transient current flowing through the transient T42)L shunt circuit (6) becomes zero, and therefore the current from the tube voltage variable regulator (2) becomes OFF.
All high voltage transformers (1
), a required voltage suitable for X-ray irradiation is subsequently supplied to the high-voltage transformer, and a normal value, for example, 60 KVP tube voltage is stably applied to the X-ray tube.

As described above, according to the present application, the time necessary for preheating the X-ray tube and the voltage suitable for preheating the X-ray tube are automatically applied to the high-voltage transformer by actuation of the operation switch, and the time required for preheating the X-ray tube is preheated. In order to reduce the transient voltage that occurs when a predetermined high voltage is applied to the rear X-ray tube, the current flowing through the high-voltage transformer is shunted, and then a constant tube voltage can be applied. The entire device can be made small, lightweight, and inexpensive without requiring a dedicated transformer for preheating.
This has advantages such as being able to prevent electrical disturbances caused by transient currents and providing a stable and durable X-ray device.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the present application. In the figure, (1) is a high voltage transformer, (2) is a tube voltage variable regulator, (3) is an X-ray tube, (5) is an operating voltage switching circuit, (
6) is a transient current shunt circuit, (7) is a DC power supply circuit, (1)
1) is a delay circuit, (12) is a timer circuit, and (13). (14) is a gate circuit, (14) a and (14) b are element parts, (16) and (17) are light receiving elements, R is a resistor,
TI (is a thyristor, C is a capacitor, SW is a switch, Tr is a transistor, and D is a light emitting element.

Claims (4)

[Claims] (1) The voltage on the primary side of the high-voltage transformer is lowered to a voltage suitable for preheating the X-ray tube by actuation of an operation switch, and after preheating for a predetermined period of time, a predetermined high voltage is applied to the X-ray tube. A working voltage switching circuit is connected in parallel to the primary side of the high voltage transformer, and a transient voltage switching circuit is connected in parallel to the primary side of the high voltage transformer to reduce the transient voltage generated in the X-ray tube when a high voltage is applied to the high voltage transformer by switching the working voltage switching circuit. and a transient current shunt circuit that bypasses the current, and on the DC power supply side,
a delay circuit that sets the time required for preheating the X-ray tube by the operation of the operation switch; a timer circuit that is activated by a delay signal from the delay circuit to set the X-ray irradiation time; It is comprised of a first gate circuit that is made conductive by a signal to switch the operating voltage switching circuit to the high voltage side, and a switching circuit that operates a second gate circuit that will be described later, and the second gate circuit is configured to switch the operating voltage switching circuit to the high voltage side. An X-ray machine characterized by comprising a first element section that brings the transient current shunt circuit into a conductive state when the circuit is conductive, and a second element section that releases the conductive state of the first element section after a considerable period of time when a transient voltage occurs. Operating voltage control circuit in the device. (2) The operating voltage switching circuit includes a voltage-dropping resistor and a thyristor connected in parallel to the resistor, and the first gate circuit includes a light-emitting element that emits light when the switching transistor is conductive, and a light-emitting element that emits light when the switching transistor is turned on. An operating voltage control circuit for an X-ray apparatus according to claim 1, comprising a light receiving element that applies a gate signal to the thyristor. (3) The transient current shunting circuit consists of a thyristor, and the first element part of the second gate circuit includes a light emitting element that emits light when the transistor is conductive, and an element that receives the light emission and applies a gate signal to the thyristor. The second element part further comprises a transistor in parallel with the light emitting element, a resistor connected between its base and collector, and a capacitor connected between its base and emitter. An operating voltage control circuit in the X-ray apparatus according to items 1 and 2. (4) Claims 1, 2, and 3 consist of a tube voltage variable regulator connected between the high-voltage transformer and the power source.
An operating voltage control circuit in the X-ray apparatus described in 1.