JPS5936400B2 - X-ray device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray apparatus using a storage battery as a power source, and more particularly to an X-ray apparatus equipped with a control circuit that suitably controls the influence of voltage drop at the terminals of the storage battery.

Generally, the terminal voltage of a storage battery decreases as the discharge progresses, and the value is approximately 2.3V/cell immediately after charging is completed, and 1.7V/cell by the time the cell needs recharging, which is 20V in the practical use range. The terminal voltage changes by about ~30%.

The amount of X-rays changes in proportion to the 2nd to 5th power of the tube voltage, so from this point of view, in a transformer-type This is a severe value.

Therefore, when using a storage battery as the power source for an X-ray device, even if the terminal voltage of the storage battery drops, it is necessary to correct it by some means to minimize changes in the amount of X-rays used due to changes in tube voltage. .

Furthermore, when the discharge of the storage battery progresses and reaches a terminal voltage that requires recharging, it is necessary to stop further discharging to protect the storage battery.

SUMMARY OF THE INVENTION An object of the present invention is to provide an X-ray control device suitable for reducing the influence of terminal voltage drop of a storage battery used as a power source for X-ray radiation and protecting the storage battery from over-discharge, in response to the above-mentioned demands. .

The present invention detects the storage battery terminal voltage immediately before X-ray radiation using a comparator or the like, and determines whether the value is below a predetermined value or not, and detects the state before the radiation even if the terminal voltage changes due to X-ray radiation. The terminal voltage drop is corrected by switching the number of turns on the primary side of the single-turn transformer that sets the tube voltage using the contact circuit.

Furthermore, when the voltage drop progresses, the X-ray emission is stopped by a circuit that operates in the same manner as described above.

The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, in which 1 is a charging circuit for rectifying AC power and charging storage batteries 3 and 14, and 2 and 12 are relays (not shown) that close during charging. Normally open contacts of the circuit, 4 and 13 are normally closed contacts of a relay circuit (also not shown) that open during charging, and 5 is a DC power source such as an inverter that converts DC power into AC power.
AC conversion circuit, 6.7 is a normally closed/normally open contact of a relay 25, which will be explained later, for switching the number of turns of a single-turn transformer 8 for adjusting the X-ray tube voltage, and 9 is for selecting a desired tube voltage. 10 is an X-ray high voltage generator, 11 is an X
It is a wire tube.

Note that the storage battery 3 is a storage battery that supplies power for X-ray radiation, and the storage battery 14 is a storage battery that supplies power to a control circuit that controls switching of the number of turns of the transformer.

In addition, in the turns switching control circuit of the single-turn transformer 8, 1
5 and 16 are resistors and Zener diodes for generating a reference voltage; 17 and 1B are resistors and variable resistors for inputting the terminal voltage of the storage battery 3 to the comparator 19;
This comparator 19 compares it with the reference voltage.

A transistor 22 is operated by the output voltage of the comparator 19 via resistors 20 and 21, and the operation of this transistor 22 drives a relay 25 to control the contacts 6 and 7 provided in the single-turn transformer. .

23 is a normally closed contact of a relay (not shown) which is open during X-ray radiation, and 24 is a contact for self-holding the relay 25.

Figure 2 shows the state of the terminal voltage of the storage battery 3 shown in Figure 1, where the vertical axis is the amount of charge or discharge, part A is charging, part B is no-load discharge state, and part 6 is discharging. The broken line in section 6 shows the state in which the terminal voltage drops when a large current flows instantaneously, such as in the case of X-ray radiation.

Further, terminal voltage A is the terminal voltage to be detected, and terminal voltage A is the final voltage at which the discharge of the storage battery should be stopped.

As can be seen from the figure, in the case of a load such as X-ray radiation, the terminal voltage which was higher than the terminal voltage to be detected before the load was applied drops to the terminal voltage to be detected or lower by applying the load.

This means that it is necessary to maintain the state immediately before radiation even during X-ray radiation.

The operation of the circuit shown in FIG. 1 will be explained below.

The terminal voltage of the storage battery 3 immediately before the X-ray emission is divided by the resistors 17 and 18 and input to one input terminal of the comparator 19 .

The reference voltage generated by the resistor 15 and Zener diode 16 is input to the other input terminal of the comparator 19, and it is checked whether the divided value of the terminal voltage of the storage battery exceeds this reference voltage. A comparator 19 makes a comparison.

If the terminal voltage is now lower than point A in FIG. 2, the output of comparator 19 turns on transistor 22, energizes relay 25, opens contact 6, and
will be closed.

This operation reduces the number of primary turns of the single-turn transformer 8, and the output voltage of the secondary output tap is corrected even if the terminal voltage of the storage battery drops.

In addition, contact 23 is open during X-ray emission, but if the terminal voltage is lower than the detection electron A point as described above,
Since the relay 25 operates immediately before the radiation is emitted, the operation of the relay is self-maintained by the contact 24 even if the contact 23 is opened.

Also, if the terminal voltage is higher than point A, the relay 25 will not operate, so even if the terminal voltage drops as shown by the dotted line in Figure 2 during X-ray radiation, the relay 25 will operate because the contact 23 is open. In either case, the state immediately before the X-ray emission will be maintained.

The input voltage to the single-turn transformer 8 during X-ray radiation is 2 in Figure 2.
The voltage at this time is approximately proportional to the terminal voltage at no load, which is shown by the solid line, if the load current is constant. From this, the terminal voltage at no load is It can be said that it is effective to measure the voltage and correct the tube voltage based on the terminal voltage drop.

FIG. 3 is a partial circuit diagram showing another embodiment of the present invention,
In this embodiment, instead of switching the number of primary turns of the single-turn transformer 8, if the terminal voltage is higher than the detection voltage, a resistor 26 is connected to the primary side of the single-turn transformer 8 to cause an appropriate voltage drop. In this method, when the voltage becomes lower, both ends of the resistor 26 are short-circuited by the contact 7, and the tube voltage is corrected by the voltage drop at the terminals of the storage battery.

Note that this contact point 7 is controlled by the same control as in FIG. 1 described above.

Furthermore, if a plurality of detection circuits 17 to 25 are provided in both FIGS. 1 and 3, even smaller tube voltages can be corrected.

Furthermore, Fig. 4 shows a circuit that uses the above-mentioned principle to stop X-ray emission when the terminal voltage reaches the white point shown in Fig. 2, and the same reference numerals as in Fig. 1 are the same. It has a function, and parts not directly related to the explanation are omitted.

As shown in the figure, a terminal voltage white point is detected by a resistor 17 and a variable resistor 18, and a relay 30 is operated by a circuit 29 equivalent to the terminal voltage detection circuit 19 to 24 in FIG. X-ray radiation is stopped by opening the contact 31 of the relay 30 inserted between the DC-AC conversion circuit 5.

As is clear from the above embodiments, according to the present invention, X
The terminal voltage of the storage battery immediately before radiation is detected, and if the value is less than a predetermined value, the tap of the single-turn transformer is switched to maintain the state immediately before radiation, and the terminal voltage of the storage battery is Since the system is designed to stop emitting X-rays when the temperature drops further, it is possible to obtain photographs with a uniform degree of blackening in X-ray photography, and to prevent damage to the storage battery due to over-discharge. It can be said to be the most suitable X-ray device that uses a storage battery as a power source.

[Brief explanation of drawings]

The attached drawings are for explaining the present invention, and are
Figure 2 is a control circuit diagram showing one embodiment of the X-ray device, Figure 2 is a diagram showing charging and discharging characteristics of a storage battery, Figure 3 is a main circuit diagram showing another embodiment of the present invention, and Figure 3 is a diagram showing the charging and discharging characteristics of a storage battery. FIG. 4 is an implementation circuit diagram for controlling the stop of X-ray radiation. 1... Charging circuit, 3, 14... Storage battery, 5... DC-AC conversion circuit, 6, 7, 24,
31...Contact, 8...Single-turn transformer, 9
...Scary switch, 10...High voltage generator, 11...X-ray tube, 15.17,
20, 21, 26, 27...Resistance, 16...
... Zener diode, 1B, 28 ... Variable resistor, 19 ... Comparator, 22 ...
...Transistor, 25,30...Relay, 2
9...Terminal voltage detection circuit.

Claims (1)

[Claims] 1. In an X-ray device that converts DC power from a storage battery into AC power, boosts and rectifies it with an X-ray high voltage generator, and applies it to the X-ray tube, detects the storage battery terminal voltage immediately before X-ray emission, Storage battery terminal voltage detection means configured to stop X-ray emission when the detection result is below a predetermined value, and means for holding the detection result even during X-ray emission; An X-ray apparatus characterized in that the X-ray tube voltage is corrected on the side next to the X-ray high voltage generator according to the voltage.