A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge and its application

Abstract

The present invention relates to the technical field of hot cathode ionization gauge driving, and discloses a cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge and its application, comprising: an AC signal phase-locked circuit, the positive output end of the AC signal phase-locked circuit is used to be connected to the input end of the heating filament of the hot cathode ionization gauge; a hot cathode ionization gauge stable emission AC driving circuit, which is used to be connected to the output end of the heating filament of the hot cathode ionization gauge, and is also respectively connected to the amplitude control end of the AC signal phase-locked circuit and the negative input end of the AC signal phase-locked circuit; a feedback circuit, which is used to be connected to the output end of the hot cathode circuit gauge, and is also respectively connected to the positive output end of the AC signal phase-locked circuit and the error signal input end of the hot cathode ionization gauge stable emission AC driving circuit. The AC phase-shift driving circuit of the present invention can extend the service life of the hot cathode ionization gauge.

Description

Technical Field

[0001] The invention relates to the technical field of hot cathode ionization gauge driving, and in particular to a hot cathode ionization gauge cathode AC phase-shift trigger driving circuit and application thereof. Background Art

[0002] At present, the main drivers of the ZJ-27 hot cathode ionization gauge are DC drive and AC drive. The advantage of DC drive is high circuit integration and high energy efficiency using the switching power supply mode, but the service life of the ionization gauge will be affected; the advantage of AC drive is that the service life of the power gauge is longer. However, since foreign AC drivers are expensive and many have been discontinued, there is an urgent need to invent a low-cost domestic AC drive circuit to drive the ZJ-27 hot cathode ionization gauge. Summary of the invention

[0003] The invention provides a cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge and application thereof, which are used to drive a ZJ-27 hot cathode ionization gauge.

[0004] The present invention is achieved through the following technical solutions:

[0005] A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge, comprising:

[0006] An AC signal phase-locked circuit, wherein the positive output end of the AC signal phase-locked circuit is used to be connected to the input end of the heating filament of the hot cathode ionization gauge, so as to provide an AC voltage for the hot cathode ionization gauge;

[0007] When the hot cathode ionization gauge works in a vacuum state (<1Pa), the formula P = 1 / K * I + / I E It can be known that the hot cathode ionization gauge stable emission AC driving circuit is used to be connected to the output end of the heating filament of the hot cathode ionization gauge, and at the same time, is also respectively connected to the amplitude control end of the AC signal phase-locked circuit and the negative input end of the AC signal phase-locked circuit, and is used to compare the sawtooth wave signal output by the amplitude control end of the AC signal phase-locked circuit and the error signal of the feedback circuit, so as to control the conduction angle of the thyristor in the hot cathode ionization gauge stable emission AC driving circuit to adjust the conduction of the AC voltage and thus adjust the power of the heating filament of the hot cathode ionization gauge, so as to achieve the effect of stable emission AC driving;

[0008] A feedback circuit is used to be connected to the output end of the hot cathode ionization gauge, and is also respectively connected to the positive output end of the AC signal phase-locked circuit and the error signal input end of the hot cathode ionization gauge stable emission AC drive circuit, and is used to compare the output current of the hot cathode ionization gauge with a reference voltage to obtain an error signal.

[0009] In some embodiments, the AC signal phase-locked circuit includes a terminal block J1, a diode D3, a diode D4, a diode D5, a resistor R10, a resistor R12, a resistor R14, a resistor R17, an electrolytic capacitor C2, a capacitor C3, a transistor Q6, and a transistor Q7. The 3-1 port and the 1-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the first toroidal transformer B1, the 3-2 port and the 1-2 port of the terminal block J1 are respectively connected to the positive poles of the diode D3 and the diode D5, the negative poles of the diode D3 and the diode D5 are commonly connected to the positive pole of the diode D4, and the positive pole of the diode D4 is also connected to one end of the resistor R12, and the resistor R1 2 is respectively connected to one end of the resistor R17 and the base of the transistor Q7, the cathode of the diode D4 is connected to the collector of the transistor Q7 and the base of the transistor Q6 through the series resistor R14, and the cathode of the diode D4 is also connected to the collector of the transistor Q6 and one end of the capacitor C3 through the series resistor R10, at the same time, the cathode of the diode D4 is grounded through the series electrolytic capacitor C2, and the positive electrode of the electrolytic capacitor C2 is connected to the cathode of the diode D4, the resistor R17, the emitter of the transistor Q6, the emitter of the transistor Q7 and the other end of the capacitor C3 are grounded, and the collector of the transistor Q6 serves as an amplitude control end to output a sawtooth wave signal.

[0010] In some embodiments, the 5-1 port and the 4-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the second toroidal transformer B2, the 5-2 port of the terminal block J1 is used to connect to the input end of the heating filament of the hot cathode ionization gauge, and the 5-2 port of the terminal block J1 is also connected to the voltage introduction end of the feedback circuit.

[0011] In some embodiments, the 2-2 port of the terminal block J1 is grounded, and the 6-2 port of the terminal block J1 is unconnected, or the 6-2 port of the terminal block J1 is grounded, and the 2-2 port of the terminal block J1 is unconnected.

[0012] In some embodiments, the hot cathode ionization stable emission AC driving circuit includes a comparator U2, a thyristor output optocoupler U1, a resistor R1, a resistor R2, a resistor R8, a resistor R9, and a bidirectional thyristor Q3, wherein the positive power input terminal and the negative power input terminal of the comparator U2 are respectively connected to the positive power supply and the negative power supply, the inverting input terminal of the comparator U2 is connected to the collector of the transistor Q6, the non-inverting input terminal of the comparator U2 is used to input an error signal, the output terminal of the comparator U2 is connected to the negative electrode of the thyristor output optocoupler U1 through the series connection of the resistor R9, and the comparator The positive pole of the transmitting tube of the thyristor output optocoupler U1 is connected to the positive power supply through the series resistor R1, one of the receiving tubes of the thyristor output optocoupler U1 is connected to the 4-2 port of the terminal block J1 through the series resistor R8, and the other receiving tube of the thyristor output optocoupler U1 is connected to the transmitting current detection end of the feedback circuit through the series resistor R2, and the receiving tube is also connected to the G pole of the bidirectional thyristor Q3, and the T1 pole and T2 pole of the bidirectional thyristor Q3 are respectively connected to the end of the resistor R8 away from the thyristor output optocoupler U1 and the end of the resistor R2 away from the thyristor output optocoupler U1.

[0013] In some embodiments, the feedback circuit includes a comparator U3, a capacitor C4, a capacitor C6, a capacitor C7, a capacitor C8, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R27, a resistor R33, an adjustable resistor VR1 and a voltage stabilizing diode D8, wherein the output end of the comparator U3 is connected to the in-phase input end of the comparator U2, the positive power input end and the negative power input end of the comparator U3 are respectively connected to the positive power supply and the negative power supply, and the positive power input end and the negative power input end of the comparator U3 are also respectively grounded through the capacitor C4 and the capacitor C6 connected in series, one end of the resistor R23 is connected to one end commonly connected to the resistor R2 and the bidirectional thyristor as an emission current detection end, one end of the resistor R21 is connected to the 5-2 port of the terminal block J1 as a voltage introduction end, the other end of the resistor R23 and the The other end of the resistor R21 is connected to ground through the series resistor R25, the resistor R27, and the resistor R33 in sequence, the capacitor C8 is connected to the resistor R33 in parallel, the end commonly connected with the resistor R27 and the resistor R33 is connected to the non-inverting input end of the comparator U3 through the series resistor R18, the center pin of the adjustable resistor VR1 is connected to the inverting input end of the comparator U3 through the series resistor R19, and the end commonly connected with the inverting input end of the comparator U3 is connected to the output end of the comparator U3 through the series capacitor C7 and the resistor R20 in sequence, one of the end pins of the adjustable resistor VR1 is grounded, and the other end pin of the adjustable resistor VR1 is connected to the positive power supply through the series resistor R22 and the resistor R24 ​​in sequence, and the positive electrode of the Zener diode D8 is grounded, and the negative electrode of the Zener diode D8 is connected to the common connection end of the resistor R22 and the resistor R24.

[0014] In some embodiments, the positive power supply and the negative power supply are +15V and -15V, respectively.

[0015] In some embodiments, two ends of the primary coil of the first toroidal transformer B1 are respectively connected to the mains.

[0016] In some embodiments, two ends of the primary coil of the second toroidal transformer B2 are respectively connected to the mains.

[0017] The present invention also discloses an application of a cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge, wherein an AC signal phase-locked circuit in the aforementioned cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge is connected to the input end of a heating filament of the hot cathode ionization gauge, and a hot cathode ionization gauge stable emission AC driving circuit and a feedback circuit are connected to the output end of the heating filament of the hot cathode ionization gauge.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] The circuit of the present invention can replace the situation where foreign components are difficult to purchase, thereby reducing costs.

[0020] The AC phase-shift driving circuit of the present invention can prolong the service life of the hot cathode ionization gauge.

[0021] Compared with foreign hot cathode ionization drives, they are high-frequency AC drives or DC drives. The high-frequency AC drive cable cannot be too long, because the cable inductance becomes larger and the drive cannot be driven. It is difficult to drive a drive cable of more than 10 meters. The service life of the DC drive will be shortened.

[0022] The present invention is cleverly applied to the emission electrons emitted by heating the hot cathode ionization gauge as an anti-peeping source, and then compared with a reference source, under the effect of synchronous (alternating current for heating the cathode ionization gauge) phase alternating current, a synchronization error signal is output, and an adjustment signal is quickly obtained. Under a vacuum state, the hot cathode ionization gauge can stably work in a stable emission state.

[0023] The invention has a simple structure and easy-to-purchase components, thus reducing financial, material and human resources and facilitating industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0025] Figure 1 A circuit connection diagram of a cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge of the present invention;

[0026] Figure 2 This is an enlarged diagram of the AC signal phase-locked circuit;

[0027] Figure 3 This is an enlarged diagram of the hot cathode ionization stable emission AC drive circuit;

[0028] Figure 4 It is an enlarged view of the feedback circuit;

[0029] Figure 5 It is the structural schematic diagram of the hot cathode ionization gauge;

[0030] Figure 6 The waveform diagram of each signal when the power of the thyristor trigger signal is 100% after adopting the thyristor phase-shift trigger technology;

[0031] Figure 7 The waveform diagram of each signal when the power of the thyristor trigger signal is 50% after adopting the thyristor phase-shift trigger technology;

[0032] Figure 8 It is a schematic diagram of signals between the output and input ends of an AC signal phase-locked circuit. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0034] This embodiment 1 provides a hot cathode ionization gauge cathode AC phase-shift trigger driving circuit, such as Figure 1 As shown, including:

[0035] An AC signal phase-locked circuit, wherein the positive output end of the AC signal phase-locked circuit is used to be connected to the input end of the heating filament of the hot cathode ionization gauge, so as to provide an AC voltage for the hot cathode ionization gauge;

[0036] When the hot cathode ionization gauge works in a vacuum state (<1Pa), the formula P = 1 / K * I + / I E It can be known that the hot cathode ionization gauge stable emission AC driving circuit is used to be connected to the output end of the heating filament of the hot cathode ionization gauge, and at the same time, is also respectively connected to the amplitude control end of the AC signal phase-locked circuit and the negative input end of the AC signal phase-locked circuit, and is used to compare the sawtooth wave signal output by the amplitude control end of the AC signal phase-locked circuit and the error signal of the feedback circuit, so as to control the conduction angle of the thyristor in the hot cathode ionization gauge stable emission AC driving circuit to adjust the conduction of the AC voltage and thus adjust the power of the heating filament of the hot cathode ionization gauge, so as to achieve the effect of stable emission AC driving;

[0037] A feedback circuit is used to be connected to the output end of the hot cathode ionization gauge, and is also respectively connected to the positive output end of the AC signal phase-locked circuit and the error signal input end of the hot cathode ionization gauge stable emission AC drive circuit, and is used to compare the output current of the hot cathode ionization gauge with a reference voltage to obtain an error signal.

[0038] Figure 1 The dotted lines in the figure are the connecting lines between the circuits and between the circuits and the hot cathode ionization gauge.

[0039] Next, the above three circuits are introduced in detail.

[0040] like Figure 2As shown, in some embodiments, the AC signal phase-locked circuit includes a terminal block J1, a diode D3, a diode D4, a diode D5, a resistor R10, a resistor R12, a resistor R14, a resistor R17, an electrolytic capacitor C2, a capacitor C3, a transistor Q6 and a transistor Q7, the 3-1 port and the 1-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the first toroidal transformer B1, the 3-2 port and the 1-2 port of the terminal block J1 are respectively connected to the positive poles of the diode D3 and the diode D5 (the 17~L and 17~N in the figure refer to the live wire and the neutral wire of 17V), the cathodes of the diode D3 and the diode D5 are commonly connected to the positive pole of the diode D4, and the positive pole of the diode D4 is also connected to the One end of the resistor R12 is connected to one end of the resistor R17 and the base of the transistor Q7 respectively. The cathode of the diode D4 is connected to the collector of the transistor Q7 and the base of the transistor Q6 through the series resistor R14, and the cathode of the diode D4 is also connected to the collector of the transistor Q6 and one end of the capacitor C3 respectively through the series resistor R10. At the same time, the cathode of the diode D4 is grounded through the series electrolytic capacitor C2, and the positive electrode of the electrolytic capacitor C2 is connected to the cathode of the diode D4. The resistor R17, the emitter of the transistor Q6, the emitter of the transistor Q7 and the other end of the capacitor C3 are grounded, and the collector of the transistor Q6 serves as an amplitude control end to output a sawtooth wave signal.

[0041] In some embodiments, the 5-1 port and the 4-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the second toroidal transformer B2, the 5-2 port of the terminal block J1 is used to connect to the input end of the heating filament of the hot cathode ionization gauge, and the 5-2 port of the terminal block J1 is also connected to the voltage introduction end of the feedback circuit.

[0042] In some embodiments, the 2-2 port of the terminal block J1 is grounded, and the 6-2 port of the terminal block J1 is unconnected, or the 6-2 port of the terminal block J1 is grounded, and the 2-2 port of the terminal block J1 is unconnected.

[0043] In some embodiments, two ends of the primary coil of the first toroidal transformer B1 are respectively connected to the mains.

[0044] In some embodiments, two ends of the primary coil of the second toroidal transformer B2 are respectively connected to the mains.

[0045] J1 is the external power input port, there are two sets of AC power supplies, one set of 7V AC power supply, and one set of ±17V AC power supply with center tap.

[0046] In some embodiments, the first toroidal transformer B1 converts the AC signal of 220V 50Hz of the mains into an AC signal of ±17V50Hz and sends it to the diodes D3 and D5 through the 3-2 port and the 1-2 port of the terminal block, the second toroidal transformer B2 converts the AC signal of 220V 50Hz of the mains into an AC signal of 7V 50Hz and sends it to the 4-1 port and the 5-1 port of the terminal block, and then sends the 7V 50HZ AC signal to the input end of the heating filament of the hot cathode ionization gauge through the 5-2 port, and the output end of the heating filament of the hot cathode ionization gauge is connected to the 4-2 port through the hot cathode ionization gauge stable emission AC driving circuit.

[0047] Specifically, a 17V 50Hz AC signal is full-wave rectified by diodes D3 and D5 to a 100HZ steamed bun wave. When the base voltage of transistor Q7 rises to about 0.7V, Q7 is turned on, transistor Q6 is turned off, and capacitor C3 starts to charge through resistor R10; when the base voltage of transistor Q7 drops to about 0.7V, Q7 is turned off, transistor Q6 is turned on, capacitor C3 is discharged, and capacitor C3 outputs a sawtooth wave with the same phase and sends it to the inverting input terminal of comparator U2 in the hot cathode ionization stable emission AC drive circuit, as shown in FIG. Figure 8 As shown, the dotted line is a steamed bun wave and the solid line is a sawtooth wave.

[0048] Diodes D3 and D5 form a full-wave rectifier, which rectifies the 50Hz AC power into a 100Hz steamed wave. Resistors R12 and R17 divide the 100Hz steamed wave and connect it to the base of transistor Q7. Diode D4 controls the 100Hz steamed wave to charge the electrolytic capacitor C2 and prevent the electrolytic capacitor C2 from discharging through resistors R12 and R17. Resistor R14 is the base current limiting resistor of transistor Q6. When transistor Q7 is turned off, electrolytic capacitor C2 turns on transistor Q6 through resistor R14. Electrolytic capacitor C2 filters the 100Hz steamed wave into a smoother DC power and stores energy. Transistor Q6 is used to discharge capacitor C3. When transistor Q6 is turned on, capacitor C3 discharges through transistor Q6. Resistor R10 and capacitor C3 form an RC charging circuit, which forms a sawtooth wave by charging and discharging capacitor C3.

[0049] In some embodiments, Figure 3As shown, the hot cathode ionization stable emission AC driving circuit includes a comparator U2, a thyristor output optical coupler U1, a resistor R1, a resistor R2, a resistor R8, a resistor R9, and a bidirectional thyristor Q3, wherein the positive power input terminal and the negative power input terminal of the comparator U2 are respectively connected to the positive power supply and the negative power supply, the inverting input terminal of the comparator U2 is connected to the collector of the transistor Q6, the inverting input terminal of the comparator U2 is used to input an error signal, the output terminal of the comparator U2 is connected to the negative electrode of the thyristor output optical coupler U1 through the resistor R9 in series, and the thyristor The positive pole of the transmitting tube of the output optocoupler is connected to the positive power supply through the series resistor R1, one of the receiving tubes of the thyristor output optocoupler U1 is connected to the 4-2 port of the terminal block J1 through the series resistor R8, and the other receiving tube of the thyristor output optocoupler U1 is connected to the transmitting current detection end of the feedback circuit through the series resistor R2, and the receiving tube is also connected to the G pole of the bidirectional thyristor Q3, and the T1 pole and T2 pole of the bidirectional thyristor Q3 are respectively connected to the end of the resistor R8 away from the thyristor output optocoupler U1 and the end of the resistor R2 away from the thyristor output optocoupler U1.

[0050] Q3 is a bidirectional thyristor, which controls the power of the heating filament by controlling the conduction time of Q3.

[0051] LampV is connected to one end (output end) of the heating filament.

[0052] U1 is the thyristor output optocoupler, which is used to isolate and drive the bidirectional thyristor Q3.

[0053] The inverting input of comparator U2 is connected to the sawtooth wave signal output by the AC signal phase-locked circuit, and the non-inverting input of comparator U2 is connected to the error signal output by the feedback circuit. The comparison result output by comparator U2 drives the thyristor output optocoupler U1 of model EL3052 to control the bidirectional thyristor Q3 of model BTA26.

[0054] Of course, comparator U2 can also be an operational amplifier, and the operational amplifier can be used as a comparator. Pin 2 (inverting input) of comparator U2 is connected to the sawtooth wave output by the AC signal phase-locked circuit, and pin 3 (non-inverting input) of comparator U2 is connected to the error signal output by the feedback circuit. The two signals are compared. If the voltage of pin 2 is higher than the voltage of pin 3, then pin 6 outputs a low level, otherwise it outputs a high level.

[0055] Resistors R1 and R9 are current limiting resistors of the thyristor output optocoupler U1, which limit the input current to prevent damage to the optocoupler U1.

[0056] Resistor R2 is the gate resistor of the bidirectional thyristor, which can improve the anti-interference ability of the bidirectional thyristor.

[0057] Resistor R8 is a current limiting resistor that triggers the bidirectional thyristor.

[0058] Through the above arrangement, the hot cathode ionization stable emission AC driving circuit of the present invention has the advantages of high adjustment accuracy, fast response speed, etc.

[0059] In some embodiments, Figure 4 As shown, the feedback circuit includes a comparator U3, a capacitor C4, a capacitor C6, a capacitor C7, a capacitor C8, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R27, a resistor R33, an adjustable resistor VR1 and a voltage stabilizing diode D8, wherein the output end of the comparator U3 is connected to the in-phase input end of the comparator U2, the positive power input end and the negative power input end of the comparator U3 are respectively connected to the positive power supply and the negative power supply, and the positive power input end and the negative power input end of the comparator U3 are also respectively connected to ground through the capacitor C4 and the capacitor C6 connected in series, one end of the resistor R23 is connected to one end commonly connected to the resistor R2 and the bidirectional thyristor as an emission current detection end, one end of the resistor R21 is connected to the 5-2 port of the terminal block J1 as a voltage introduction end, the other end of the resistor R23 and the resistor The other end of R21 is connected to ground through resistors R25, R27 and R33 in series in sequence, the capacitor C8 is connected to the resistor R33 in parallel, the end commonly connected with the resistor R27 and the resistor R33 is connected to the non-inverting input of the comparator U3 through the resistor R18 in series, the center pin of the adjustable resistor VR1 is connected to the inverting input of the comparator U3 through the resistor R19 in series, and the end commonly connected with the inverting input of the comparator U3 is connected to the output of the comparator U3 through the capacitor C7 and the resistor R20 in series in sequence, one of the end pins of the adjustable resistor VR1 is connected to ground, the other end pin of the adjustable resistor VR1 is connected to the positive power supply through the resistors R22 and R24 in series in sequence, the positive electrode of the Zener diode D8 is grounded, and the negative electrode of the Zener diode D8 is connected to the common connection end of the resistors R22 and R24.

[0060] In some embodiments, the positive power supply and the negative power supply are +15V and -15V, respectively.

[0061] When the hot cathode ionization gauge is heated to a red-hot state, an emission current is emitted, and the emission current detection end is connected to the non-inverting input end of the comparator U3 through resistors R23, R25, R27, and R18, and the reference voltage signal is connected to the inverting input end of the comparator U3 through resistor R19 for voltage comparison and amplification. The comparator U3 outputs an error signal and sends it to the non-inverting input end of the comparator U2 op amp in the hot cathode ionization gauge stable emission AC drive circuit for comparison with the sawtooth wave. When it is lower than or higher than the stable emission current, the light-emitting current of the optocoupler U1 decreases or increases, and the output voltage of U1 also decreases or increases accordingly, and reaches the input end of the controllable gauge Q3 to control the conduction angle of the thyristor to adjust the heating power of the heating filament cathode, thereby controlling the ion emission current.

[0062] Comparator U3 may also be an operational amplifier.

[0063] Capacitor C4 and capacitor C6 are power supply filter capacitors for operational amplifier U3.

[0064] Operational amplifier U3 is used for the error between reference voltage and feedback voltage, and outputs the error signal at pin 6 to be connected to the thyristor trigger circuit.

[0065] Resistor R20, capacitor C7 and resistor R19 form a proportional integral circuit.

[0066] The resistor R24, the resistor R22, the adjustable resistor VR1 and the voltage zener diode D8 constitute a voltage reference generating circuit.

[0067] The resistor R21, the resistor R23, the resistor R25, the resistor R27, the resistor R33, the resistor R18 and the capacitor C8 convert the emitted electron current into a voltage for detection.

[0068] 7V and LampV are connected to both ends of the heating filament of the hot cathode.

[0069] In some embodiments, an application of a cathode AC phase-shift trigger drive circuit of a hot cathode ionization gauge is also disclosed, wherein an AC signal phase-locked circuit in the aforementioned cathode AC phase-shift trigger drive circuit of a hot cathode ionization gauge is connected to the input end of the heating filament of the hot cathode ionization gauge, and the hot cathode ionization gauge stable emission AC drive circuit and feedback circuit are connected to the output end of the heating filament of the hot cathode ionization gauge.

[0070] like Figure 5The figure shows the schematic diagram of the ZJ-27 hot cathode ionization gauge, where the hot cathode F is a heating filament. When the heating filament is heated to a red-hot state by the heating filament driving circuit during operation, electrons will be emitted outward. The electrons will be accelerated toward the gate when pulled by the high voltage of the grid C. Most of the electrons pass through the grid, and because the voltage of the collector T is negative relative to the grid C, the electrons are pushed back by the collector T and then accelerated back to the grid. In this way, the probability of electrons colliding with gas molecules increases during the round-trip movement, ionizing more gas molecules and turning them into positive ions and secondary electrons. The positive ions will be attracted by the collector T with the lowest potential, forming a current Ii in the collector circuit. The current is numerically the size of the positive ion flow, and the gas pressure is measured by measuring the current.

[0071] In the hot cathode ionization gauge, under the condition of constant electron current Ie, the collector ion current Ii is proportional to the gas molecule density in the gauge tube space, so to measure the gas pressure in the gauge tube space, it is necessary to first provide a constant electron current Ie (i.e., ion emission current). The present invention adjusts the heating power of the hot cathode F by measuring Ie to control the stability of the electron current Ie. In this circuit, before the stable emission current is reached or when a sudden change occurs due to external interference, such as when the emission current becomes smaller, the voltage obtained by R33 decreases, the input voltage of the same-direction input end of U3 decreases, the output voltage of the 6-pin of U3 decreases, the output voltage of the 6-pin of the same-direction comparison amplifier of U2 decreases, the voltage of the 2-pin of the U1 optocoupler decreases, the current between the 1-pin and the 2-pin increases, the internal light emission becomes stronger, the output voltage of the 6-pin increases, the voltage of the 3-pin of the controllable gauge Q3 increases, the conduction interval changes voltage, the hot cathode heating changes current and increases, and the emission current gradually increases. On the contrary, if the emission current increases, the process is the opposite, and the step-by-step adjustment is made to finally reach the required emission current.

[0072] The driving circuit of the present invention mainly adopts the thyristor phase shift triggering technology, that is, the hot cathode ionization gauge stable emission AC driving circuit adopts the change of the starting point position or the ending position of each cycle conduction to adjust the output power or voltage of the filament of the hot cathode ionization gauge. In fact, the conduction amount of the thyristor is controlled by controlling the conduction angle of the thyristor. For example Figure 6 This is the 100% power output waveform. Figure 7 It is a 50% power output waveform, and the 50% output voltage waveform is a defective sine wave.

[0073] The controllable gauge can be triggered only when it passes through zero, which is a characteristic of the controllable gauge, and the load is the hot cathode filament of the present invention.

[0074] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge. It is characterized in that include: An AC signal phase-locked circuit, wherein the positive output end of the AC signal phase-locked circuit is used to be connected to the input end of the heating filament of the hot cathode ionization gauge, so as to provide an AC voltage for the hot cathode ionization gauge; A hot cathode ionization gauge stable emission AC driving circuit is used to be connected to the output end of the heating filament of the hot cathode ionization gauge, and is also connected to the amplitude control end of the AC signal phase-locked circuit and the negative input end of the AC signal phase-locked circuit respectively, and is used to compare the sawtooth wave signal output by the amplitude control end of the AC signal phase-locked circuit and the error signal of the feedback circuit, so as to control the conduction angle of the thyristor in the hot cathode ionization gauge stable emission AC driving circuit to adjust the conduction of the AC voltage and thus adjust the power of the heating filament of the hot cathode ionization gauge, so as to achieve the effect of stable emission AC driving; A feedback circuit is used to be connected to the output end of the hot cathode ionization gauge, and is also respectively connected to the positive output end of the AC signal phase-locked circuit and the error signal input end of the hot cathode ionization gauge stable emission AC drive circuit, and is used to compare the output current of the hot cathode ionization gauge with a reference voltage to obtain an error signal.

2. A hot cathode ionization gauge cathode AC phase-shift trigger driving circuit according to claim 1, It is characterized in that The AC signal phase-locked circuit includes a terminal block J1, a diode D3, a diode D4, a diode D5, a resistor R10, a resistor R12, a resistor R14, a resistor R17, an electrolytic capacitor C2, a capacitor C3, a transistor Q6 and a transistor Q7. The 3-1 port and the 1-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the first toroidal transformer B1, the 3-2 port and the 1-2 port of the terminal block J1 are respectively connected to the positive electrodes of the diode D3 and the diode D5, the negative electrodes of the diode D3 and the diode D5 are commonly connected to the positive electrode of the diode D4, and the positive electrode of the diode D4 is also connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the positive electrode of the diode D4. The ends are respectively connected to one end of the resistor R17 and the base of the transistor Q7, the cathode of the diode D4 is connected to the collector of the transistor Q7 and the base of the transistor Q6 through the series resistor R14, and the cathode of the diode D4 is also connected to the collector of the transistor Q6 and one end of the capacitor C3 through the series resistor R10. At the same time, the cathode of the diode D4 is grounded through the series electrolytic capacitor C2, and the positive electrode of the electrolytic capacitor C2 is connected to the cathode of the diode D4, the resistor R17, the emitter of the transistor Q6, the emitter of the transistor Q7 and the other end of the capacitor C3 are grounded, and the collector of the transistor Q6 serves as an amplitude control end to output a sawtooth wave signal.

3. A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge according to claim 2, It is characterized in that The 5-1 port and the 4-1 port of the terminal block J1 are respectively connected to the two ends of the secondary coil of the second toroidal transformer B2, the 5-2 port of the terminal block J1 is used to connect the input end of the heating filament of the hot cathode ionization gauge, and the 5-2 port of the terminal block J1 is also connected to the voltage introduction end of the feedback circuit.

4. A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge according to claim 2, It is characterized in that The 2-2 port of the terminal block J1 is grounded, and the 6-2 port of the terminal block J1 is unconnected, or the 6-2 port of the terminal block J1 is grounded, and the 2-2 port of the terminal block J1 is unconnected.

5. A hot cathode ionization gauge cathode AC phase-shift trigger driving circuit according to claim 2, It is characterized in that The hot cathode ionization stable emission AC driving circuit includes a comparator U2, a thyristor output optocoupler U1, a resistor R1, a resistor R2, a resistor R8, a resistor R9, and a bidirectional thyristor Q3, wherein the positive power input terminal and the negative power input terminal of the comparator U2 are respectively connected to the positive power supply and the negative power supply, the inverting input terminal of the comparator U2 is connected to the collector of the transistor Q6, the inverting input terminal of the comparator U2 is used to input an error signal, the output terminal of the comparator U2 is connected to the negative electrode of the thyristor output optocoupler U1 through the resistor R9 in series, and the thyristor output The positive pole of the transmitting tube of the optocoupler U1 is connected to the positive power supply through the series resistor R1, one of the receiving tubes of the thyristor output optocoupler U1 is connected to the 4-2 port of the terminal block J1 through the series resistor R8, and the other receiving tube of the thyristor output optocoupler U1 is connected to the transmitting current detection end of the feedback circuit through the series resistor R2, and the receiving tube is also connected to the G pole of the bidirectional thyristor Q3, and the T1 pole and T2 pole of the bidirectional thyristor Q3 are respectively connected to the end of the resistor R8 away from the thyristor output optocoupler U1 and the end of the resistor R2 away from the thyristor output optocoupler U1.

6. A cathode AC phase-shift trigger driving circuit for a hot cathode ionization gauge according to claim 5, It is characterized in that The feedback circuit includes a comparator U3, a capacitor C4, a capacitor C6, a capacitor C7, a capacitor C8, a resistor R18, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R27, a resistor R33, an adjustable resistor VR1 and a voltage stabilizing diode D8, wherein the output end of the comparator U3 is connected to the in-phase input end of the comparator U2, the positive power input end and the negative power input end of the comparator U3 are respectively connected to the positive power supply and the negative power supply, and the positive power input end and the negative power input end of the comparator U3 are also respectively grounded through the capacitor C4 and the capacitor C6 connected in series, one end of the resistor R23 is connected to one end commonly connected to the resistor R2 and the bidirectional thyristor as an emission current detection end, one end of the resistor R21 is connected to the 5-2 port of the terminal block J1 as a voltage introduction end, the other end of the resistor R23 and the resistor R2 The other end of the adjustable resistor VR1 is connected to ground through the series resistor R25, the resistor R27 and the resistor R33 in sequence, the capacitor C8 is connected in parallel with the resistor R33, the end commonly connected with the resistor R27 and the resistor R33 is connected to the non-inverting input end of the comparator U3 through the series resistor R18, the center pin of the adjustable resistor VR1 is connected to the inverting input end of the comparator U3 through the series resistor R19, and the end commonly connected with the inverting input end of the comparator U3 is connected to the output end of the comparator U3 through the series connection of the capacitor C7 and the resistor R20 in sequence, one of the end pins of the adjustable resistor VR1 is grounded, the other end pin of the adjustable resistor VR1 is connected to the positive power supply through the series connection of the resistor R22 and the resistor R24 ​​in sequence, the positive electrode of the Zener diode D8 is grounded, and the negative electrode of the Zener diode D8 is connected to the common connection end of the resistor R22 and the resistor R24.

7. The cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge according to claim 5, It is characterized in that The positive power supply and the negative power supply are +15V and -15V respectively.

8. The cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge according to claim 2, It is characterized in that Two ends of the primary coil of the first toroidal transformer B1 are respectively connected to the mains.

9. The cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge according to claim 3, It is characterized in that Two ends of the primary coil of the second toroidal transformer B2 are respectively connected to the mains.

10. Application of a cathode AC phase-shift trigger drive circuit for a hot cathode ionization gauge. It is characterized in that The AC signal phase-locked circuit in the cathode AC phase-shift trigger driving circuit of a hot cathode ionization gauge described in any one of claims 1 to 9 is connected to the input end of the heating filament of the hot cathode ionization gauge, and the hot cathode ionization gauge stable emission AC driving circuit and feedback circuit are connected to the output end of the heating filament of the hot cathode ionization gauge.

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