JPS6264960A - System and apparatus for measuring current of medical x-ray tube using clamp current detector - Google Patents

Abstract

PURPOSE:To make it possible to rapidly measure the current of a medical Z-ray tube without opening a line, by clamping a high voltage cable by a clamp current detector. CONSTITUTION:A clamp current detector A is constituted by integrating an iron core 18, a detection element 1 and a feedback coil 19 and connected to the main body B of a medical X-ray tube measuring apparatus by a lead wire 2. The detector A clamping a high voltage cable generates output voltage V proportional to the medical X-ray tube current I having flowed to the high voltage cable and the voltage V is amplified by an amplifier 4 to be fed back to a feedback coil 19 to be stabilized and guided to an integrating circuit through a switch 14 and integrated. The switch 14 is closed at the same time when the current I flows and opened after the current I was stopped so as to be slightly delayed. Further, integration is performed by closing a switch 15 only for a set time (t) and charging an integrating condenser 17 with voltage V. When a switch 16 is opened at the same time when the switch 15 is closed and the voltage V charged in the condenser 17 is held to a display holding circuit 7 for about 10 sec and displayed on a display device 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] By using the beam 2-amp current detector of the present invention, it is possible to measure the medical Xa tube current without having to open the line as in the past. Medical X using a clamp current detector
This article relates to a tube current measurement method and its device.
[Prior Art] Conventionally, the method for measuring medical X-ray tube current is to open a part of the line and insert an ammeter or current detector to measure the current.

Figure 3 shows an example in which an ammeter is inserted. In the figure, D is a high voltage generator, E is an X#J tube current ammeter is a medical X-ray tube, 11 is a primary winding, and 12 is a secondary winding. line, 13 is a rectifier,
3 is a high voltage cable, which connects X#i! to the neutral point of the secondary winding 12 of the high voltage generator. Figure 4 shows an example of inserting a current detector. In the figure, D is a high voltage generator, X is a medical X-ray tube, and Y is a current. The detector, Z is an X-ray tube current indicator, and 3 is a high voltage cable. A part of the high voltage cable 3 that applies high voltage to the medical X-ray tube X is opened and the current detector Y is inserted. It is a method of measurement.

Either method has the disadvantage of requiring the railway to be opened.

[Problem that the invention seeks to solve]

The conventional method of measuring the medical XIs tube current by opening the line has the following problems.

(With the method of inserting an ammeter at the neutral point, only the current flowing through the neutral point can be measured.

(2) In the method of inserting a current detector into a high voltage circuit, ■
The current detector must be housed in a high voltage resistant case.

■ The total length of the connection cable becomes longer and a slight voltage drop is observed.

■ Even if you use a special connection cable to avoid the above ■, a voltage drop of about 1 inch cannot be avoided. ■ To measure the tube current flowing to the anode and cathode sides, insert a current detector into each circuit. Must.

■ When measuring the tube current flowing through the cathode side, special measures are required to eliminate the influence of the filament current of the X-ray tube.

The present invention seeks to solve the above problems.

[Means for solving problems]

The present invention uses a clamp current detector to measure the medical X-ray tube current flowing through the high-voltage cable by simply holding the high-voltage cable in its mouth without opening the line. This is a circuit system that displays the numerical value.

The clamp current detector has an iron core, a detection element, and a feedback coil integrated, and the medical X# flowing through the clamped line.
Due to the magnetic flux produced by the J tube current I, the clamp current detector generates an output voltage V proportional to the medical X-ray tube current I. This output voltage V is amplified by an amplifier AMP, fed back to a feedback coil to stabilize it, and integrated for a certain period of time by an integrating circuit and a synchronizing circuit. The average value of the tube current is determined, and the display holding circuit displays this on the display for a predetermined period of time.

[For production]

The present invention enables medical X-ray tube current to be measured with a simple operation of clamping the high voltage cable 7' with a clamp current detector without opening the high voltage line. Useful for inspection, etc.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.
The explanation will be based on bl.

In Figure 1, A is a clamp current detector, 1 is a detection element, 2 is a lead wire, a 3-wire high voltage cable, and B is a medical X#
3! The main body of the tube current measuring device, 4 is an amplifier, 5 is an integrating circuit,
6 is a synchronization circuit, 7 is a display holding circuit, 8 is a display device,
The output voltage detected by the clamp current detector A is measured by the main body B of the medical X-ray tube current measuring device.

Figure 2 (al is the electrical circuit diagram of the present invention, Figure 2 tb
1 is a block diagram of the present invention. The following explanation will be given based on FIG. 2 181 and lbl. The clamp detector A has an iron core 18, a detection element 1, and a feedback coil 19 integrated, and is connected to the medical X-ray tube measuring device main body B with a lead wire 2. be done. A clamp current detector A holding a high voltage cable in its mouth generates an output voltage V proportional to the medical X-ray tube current I flowing through the high voltage cable, and this output voltage V is amplified by AMP4 and fed back to the feedback coil. Stability is important. This output voltage V is led to an integrating circuit via a switch S114 and is integrated. The switch S114 is closed at the same time as the current I flows, as shown in FIG. Further, the integration is performed by closing the switch S215 for a preset time t to charge the output voltage V into the integrating capacitor 017. Further, when the switch S215 is closed, the output voltage 10 of the AND gate 2 shown in FIG.
6 is opened and the output voltage V charged in the integrating capacitor 017 is held in the display holding circuit 7 for about 10 seconds. This held output voltage ■ can be displayed on the display 8.

The displayed value of the medical X-ray tube current I to be measured changes after about 10 seconds when the switch S316 closes and the integrating capacitor 017
The output voltage V that had been charged is discharged and the display 8 returns to zero.

〔Effect of the invention〕

Since the present invention has the above-described structural functions, the following effects can be obtained.

ill Medical X#J tube current that flows only for a short time can be measured without opening the line.

(2) Since the line is not opened, there is no need for a current detector housed in a high-voltage case and a connecting cable, which were required in the past, allowing for easy and quick measurements.

13) In addition to being simple, since no connecting cable is used, there is no slight voltage drop due to the connecting cable, which has the effect of improving measurement accuracy.

(4) With the conventional open-circuit method, when measuring the tube current flowing to the cathode side, special measures were required to avoid the influence of the filament current, and there was a slight voltage drop due to this, but this The measurement accuracy has been improved.

(5) In the conventional method, when using a special connection cable with low voltage drop, separate connection cables had to be used for the anode side and the cathode side, but in the present invention, the anode side and the cathode side Any tube current can be easily measured using the same method and equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of the present invention, FIG. 2 tal is an electric circuit diagram of the present invention, and FIG. 2 tbl is a block diagram.
3 and 4 are explanatory diagrams of conventional examples of OA...
... Clamp current detector B ... Medical X-ray tube current measuring device body L ...
...Detection element 2...Lead wire 3...High voltage cable 4...Amplifier 5...Integrator circuit 6...Synchronization circuit 1 ...Display holding circuit 8...Display device

Claims (2)

[Claims] (1) The clamp current detector has an iron core, a detection element, and a feedback coil integrated, and the magnetic flux created by the medical X-ray tube current I flowing through the clamped line causes the clamp current detector to generates an output voltage V proportional to . This output voltage V is amplified by the amplifier AMP and fed back to the feedback coil to stabilize it, and is integrated over a certain period of time by an integrating circuit and a synchronizing circuit to obtain the average value of the medical X-ray tube current I, which is then sent to the display holding circuit. A medical X-ray tube current measurement method using a clamp current detector that displays a set time on a display. (2) A medical X-ray tube current measuring device using a clamp current detector consisting of a clamp current detector A and a medical X-ray tube current measuring device main body B, wherein the medical X-ray tube current measuring device main body B is A medical X-ray tube current measuring device using a clamp current detector, characterized in that it is composed of an amplifier 4, an integrating circuit 5, a synchronizing circuit 6, a display holding circuit 7, and a display 8.