CN216933261U

CN216933261U - Voltage control circuit and dental X-ray machine bulb tube assembly

Info

Publication number: CN216933261U
Application number: CN202123456099.0U
Authority: CN
Inventors: 蓝瑞鹏; 先云才
Original assignee: Zhuhai Siger Medical Equipment Co ltd
Current assignee: Zhuhai Siger Medical Equipment Co ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-07-12
Anticipated expiration: 2031-12-31

Abstract

The utility model discloses a voltage control circuit and a dental X-ray machine ball tube assembly, wherein the voltage control circuit comprises a first transformer, a positive voltage doubling rectifying circuit and a negative voltage doubling rectifying circuit; the method comprises the following steps that high-frequency complementary pulse voltage signals are respectively connected to two ends of a first transformer, and are boosted to obtain an intermediate voltage signal Vm; a forward voltage doubling rectifying circuit performs forward voltage doubling rectification on one path of the intermediate voltage signal Vm to obtain positive W/2 anode voltage and inputs the positive W/2 anode voltage to the anode of the ray tube; a negative voltage doubling rectifying circuit performs negative voltage doubling rectification on the other path of the intermediate voltage signal Vm to obtain a negative W/2 cathode voltage, and the negative W/2 cathode voltage is input to a cathode filament of the ray tube; w is the operating voltage of the tube; the voltage control circuit also comprises a grounding circuit which connects the shell of the bulb tube assembly with 0V. The utility model reduces the voltage difference between the inner part of the bulb tube assembly and the outer shell of the bulb tube assembly, thereby reducing the volume and the weight of the bulb tube assembly.

Description

Voltage control circuit and dental X-ray machine bulb tube assembly

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a voltage control circuit and a dental X-ray machine bulb component.

Background

The bulb tube component is the core device of the dental X-ray machine, the ray tube is the core device of the bulb tube component, at present, the generation method of the anode voltage of the ray tube is as follows: the input voltage is converted into high-frequency pulse voltage by direct current through an inverter circuit, and the high-frequency pulse voltage is boosted and voltage-multiplying rectified by a transformer to obtain positive 70 kilovolts; positive 70kv was connected to the tube anode and 0V to the tube cathode filament. Because the anode voltage of the tube is too high, it is common to use a transformer to rectify the voltage, and the high voltage components of the tube are fixedly assembled in a housing, and then sealed by injecting transformer oil, so as to form a bulb tube assembly as the industry standard.

Since the voltage difference between the anode of the tube and the casing is 70kv, in order to prevent creepage, it is necessary to consider reserving a space large enough to ensure a safe creepage distance, so that the existing bulb assembly is bulky and the amount of transformer oil is increased.

Furthermore, since the tube generates radiation, scattered radiation that irradiates areas of radiation leakage outside the patient must be considered, and there are two general approaches:

1: reduce the radiation and reveal at the lead cover that bulb subassembly shell package one deck 2mm is thick, because bulb subassembly shell bulkiness is bigger, the parcel lead cover weight further aggravates, this scheme is the scheme that current mainstream adopted.

2: a lead sheath with the thickness of 2mm is coated on a tube shell of the tube, and because the lead sheath is very close to the anode high-voltage end of the tube, the lead sheath needs to be connected with a midpoint potential of plus 35 kilovolts to prevent discharge caused by unstable voltage difference outside the tube, and the voltage of plus 35 kilovolts needs to be generated by certain circuit boosting, so that the volume of a bulb tube component is further increased and is not compensated, and the lead sheath is rarely used.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a voltage control circuit and a dental X-ray machine bulb assembly, and the voltage difference between the inside of the bulb assembly and the shell of the bulb assembly is reduced through the improvement of the circuit. The utility model is realized by the following technical scheme:

a voltage control circuit for controlling the voltage of a tube in a dental X-ray machine bulb assembly; the voltage control circuit is characterized by comprising a first transformer, a positive voltage doubling rectifying circuit and a negative voltage doubling rectifying circuit; the method comprises the following steps that high-frequency complementary pulse voltage signals are respectively connected to two ends of a first transformer, and are boosted to obtain an intermediate voltage signal Vm; a forward voltage-multiplying rectification circuit carries out forward voltage-multiplying rectification on one path of the intermediate voltage signal Vm to obtain positive W/2 anode voltage and inputs the anode voltage to the anode of the ray tube; a negative voltage doubling rectifying circuit performs negative voltage doubling rectification on the other path of the intermediate voltage signal Vm to obtain a negative W/2 cathode voltage and inputs the negative W/2 cathode voltage to a cathode filament of the ray tube; w is the operating voltage of the tube; the voltage control circuit also comprises a grounding circuit which connects the shell of the bulb tube assembly with 0V.

Specifically, the forward voltage-multiplying rectifying circuit includes six forward voltage-multiplying rectifying sub-circuits connected in series.

Specifically, the negative voltage-multiplying rectifying circuit includes six negative voltage-multiplying rectifying sub-circuits connected in sequence.

Preferably, the voltage control circuit further comprises a voltage division circuit formed by a resistor R1 and a resistor R2, and the anode voltage of positive W/2 is sampled through the node of the resistor R1 and the resistor R2.

Preferably, the voltage control circuit further comprises a second transformer, and the two ends of the second transformer are respectively connected to the complementary voltage signals FD1 and FD2, and step down the complementary voltage signals FD1 and FD2 to obtain a preheating voltage signal Vn for preheating the filament of the tube in advance.

A dental X-ray machine bulb tube component comprises a shell, a ray tube and a voltage control circuit component, wherein the ray tube and the voltage control circuit component are arranged in the shell; the voltage control circuit component is provided with the voltage control circuit.

Preferably, the tube envelope is coated with lead.

Preferably, the tube and voltage control circuit assembly is sealed within the housing by transformer oil.

The utility model has the beneficial effects that: by adjusting the voltage doubling circuit, two paths of high-voltage signals are generated, namely positive W/2 and negative W/2(W is the working voltage of the ray tube, such as 70 kilovolts), the positive W/2 voltage signal is connected with the anode of the ray tube, the negative W/2 voltage signal is connected with the cathode filament of the ray tube, and the shell of the bulb tube assembly is connected with 0V, so that the voltage difference between the anode of the ray tube and the shell of the bulb tube assembly is reduced, namely the voltage is reduced to W/2, the creepage distance can be reduced, the volume of the bulb tube assembly is further reduced, and the weight can be correspondingly reduced. Meanwhile, the radiation-proof lead sheath can be wrapped on the tube shell of the ray tube, and the voltage of the midpoint potential is changed into 0V (grounded), so that the midpoint voltage is obtained without adding a circuit. In addition, because the radiation-proof lead cover is wrapped outside the ray tube, a large lead cover is omitted from the shell of the bulb tube assembly, the weight of the assembly is further reduced, and the bulb tube assembly is economical and environment-friendly.

Drawings

Fig. 1 is a schematic diagram of a voltage control circuit according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be understood that the described embodiments are merely exemplary of the present application and are not intended to limit the present application to the particular embodiments disclosed herein.

As shown in fig. 1, the present embodiment provides a voltage control circuit for controlling the voltage of a tube in a bulb assembly of a dental X-ray machine, the voltage control circuit including a first transformer T1, a positive voltage doubler rectifier circuit, a negative voltage doubler rectifier circuit, and a ground line connecting the bulb assembly housing to 0V.

Two ends of the first transformer T1 are respectively connected with high-frequency complementary pulse voltage signals ED1 and ED2, and the midpoint is connected with a midpoint voltage signal ED. Specifically, ED1 and ED2 may be pulse signals of 16.8V, respectively, and the first transformer T1 boosts the high-frequency complementary pulse voltage signals ED1 and ED2 to obtain an intermediate voltage signal Vm, which is about 5800V. The intermediate voltage signal Vm is divided into two paths and respectively input to a positive voltage doubling rectifying circuit and a negative voltage doubling rectifying circuit, the positive voltage doubling rectifying circuit performs positive voltage doubling rectifying on one path of the intermediate voltage signal Vm to obtain positive 35 kilovolt anode voltage and inputs the anode voltage to the anode of the ray tube D17; the negative voltage doubling rectifying circuit performs negative voltage doubling rectifying on the other path of the intermediate voltage signal Vm to obtain a cathode voltage of negative 35 kilovolts, and the cathode voltage is input to a cathode filament of the ray tube D17.

Specifically, the forward voltage-doubling rectifying circuit comprises six forward voltage-doubling rectifying sub-circuits connected in sequence, such as a first forward voltage-doubling rectifying sub-circuit consisting of a capacitor C1 and a diode D1, and a sixth forward voltage-doubling rectifying sub-circuit consisting of a capacitor C6 and a diode D6. Similarly, the negative voltage-doubling rectifying circuit comprises six negative voltage-doubling rectifying sub-circuits connected in sequence, such as a first negative voltage-doubling rectifying sub-circuit formed by a capacitor C9 and a diode D9, and a sixth negative voltage-doubling rectifying sub-circuit formed by a capacitor C16 and a diode D14.

In this embodiment, in order to monitor the output voltage of the forward voltage-doubling rectifying circuit, a voltage-dividing circuit formed by a resistor R1 and a resistor R2 is further provided, the sampled voltage signal KV _ FB is collected through a node of the resistor R1 and the resistor R2, and the sampled voltage signal KV _ FB is used for safety monitoring or auxiliary control by judging whether the sampled voltage signal KV _ FB is normal or not.

In this embodiment, in order to preheat the filament of the tube, the voltage control circuit further includes a second transformer T2, two ends of the second transformer T2 are respectively connected to the complementary voltage signals FD1 and FD2, and the voltage is reduced to obtain a preheating voltage signal Vn, and the midpoint is connected to the midpoint voltage signal FV. Specifically, FV, FD1 and FD2 may be 7V voltage signals, respectively, and the first transformer T2 steps down FD1 and FD2 to obtain a 3V preheat voltage signal Vn.

The embodiment also provides a dental X-ray machine bulb component, which comprises a shell, a ray tube and a voltage control circuit component, wherein the ray tube and the voltage control circuit component are arranged in the shell; the voltage control circuit is arranged on the voltage control circuit component, the tube and the voltage control circuit component are sealed in the shell through transformer oil, and a tube shell of the tube is coated with a lead sheet.

The operation principle of the voltage control circuit and the dental X-ray machine bulb assembly is described as follows:

two groups of high-frequency complementary pulse voltages ED1 and ED2 output from an inverter circuit are boosted by a transformer T1 to obtain an intermediate voltage signal Vm of about 5800 volts;

2: one path of an intermediate voltage signal Vm of about 5800 volts is subjected to voltage doubling rectification by a forward voltage doubling rectification circuit to obtain positive 35 kilovolts, one path of the output of the forward voltage doubling rectification circuit is connected to an anode of a ray tube D17 (namely a pin 1 of D17 in the diagram 1), and the other path of the output of the forward voltage doubling rectification circuit is subjected to voltage division by a sampling resistor R2 and R1 to obtain a sampling voltage signal KV _ FB which is fed back to the outside, for example, a main control module of an X-ray machine;

3: the other path of the intermediate voltage signal Vm of about 5800 v is subjected to voltage doubling rectification by a negative voltage doubling rectification circuit to obtain negative 35kv, and is connected to the cathode filament anode of the incident tube D17 (i.e., pin 2 of D17 in fig. 1).

4: in order to prevent radiation leakage, a layer of lead is wrapped on a tube shell of the ray tube, only a small amount of lead is needed to be wrapped, the lead needs to be connected with a midpoint potential of 0V, and if the position A marked in the figure is connected with 0V;

5: the preheating voltage of the filament of the ray tube is about 3V, and is obtained by reducing the voltages of two groups of externally input complementary voltages FD1 and FD2 by a transformer T2;

6: from the electrical insulation diagram, the voltage difference between the inner part of the bulb tube assembly and the outer shell is improved to 35KV from 70KV, the creepage distance between the tube and the outer shell is obviously shortened structurally, and the inner space is greatly reduced.

Therefore, in the embodiment, two paths of high-voltage signals, namely positive 35kv and negative 35kv, are generated by adjusting the voltage doubling circuit, the positive 35kv is connected with the anode of the tube, the negative 35kv is connected with the cathode filament of the tube, and the outer shell of the bulb tube assembly is connected with 0V. Meanwhile, the radiation-proof lead sheath can be wrapped on the tube shell of the ray tube, and the voltage of the midpoint potential is changed into 0V (grounded), so that the midpoint voltage is obtained without adding a circuit. In addition, because the radiation-proof lead cover is wrapped outside the ray tube, a large lead cover is omitted from the shell of the bulb tube assembly, the weight of the assembly is further reduced, and the bulb tube assembly is economical and environment-friendly.

The above embodiments are merely for full disclosure and not for limitation of the present invention, and any replacement of equivalent technical features, which can be obtained without inventive work based on the gist of the present invention, should be considered as the scope of the present disclosure.

Claims

1. A voltage control circuit for controlling the voltage of a tube in a dental X-ray machine bulb assembly; the voltage control circuit is characterized by comprising a first transformer, a positive voltage doubling rectifying circuit and a negative voltage doubling rectifying circuit; the method comprises the following steps that high-frequency complementary pulse voltage signals are respectively connected to two ends of a first transformer, and are boosted to obtain an intermediate voltage signal Vm; a forward voltage doubling rectifying circuit performs forward voltage doubling rectification on one path of the intermediate voltage signal Vm to obtain positive W/2 anode voltage and inputs the positive W/2 anode voltage to the anode of the ray tube; a negative voltage doubling rectifying circuit performs negative voltage doubling rectification on the other path of the intermediate voltage signal Vm to obtain a negative W/2 cathode voltage, and the negative W/2 cathode voltage is input to a cathode filament of the ray tube; w is the operating voltage of the tube; the voltage control circuit also comprises a grounding circuit which connects the shell of the bulb tube assembly with 0V.

2. The voltage control circuit of claim 1, wherein the forward voltage doubling rectifying circuit comprises six forward voltage doubling rectifying sub-circuits connected in series.

3. The voltage control circuit of claim 1, wherein the negative voltage doubling rectifying circuit comprises six negative voltage doubling rectifying sub-circuits connected in series.

4. The voltage control circuit of claim 1, further comprising a voltage divider circuit formed by a resistor R1 and a resistor R2, wherein the anode voltage of positive W/2 is sampled through the node of the resistor R1 and the resistor R2.

5. The voltage control circuit of claim 1, further comprising a second transformer, wherein the second transformer receives complementary voltage signals FD1 and FD2 from two ends of the second transformer, respectively, and reduces the voltage to obtain a preheating voltage signal Vn for preheating the filament of the tube in advance.

6. A dental X-ray machine bulb tube component comprises a shell, a ray tube and a voltage control circuit component, wherein the ray tube and the voltage control circuit component are arranged in the shell; the voltage control circuit component is provided with the voltage control circuit of any one of claims 1 to 5.

7. The dental X-ray machine bulb assembly of claim 6, wherein the tube housing is lead clad.

8. The dental X-ray machine bulb assembly of claim 6 or 7, wherein the tube and voltage control circuit assembly is sealed within the housing by transformer oil.