CN203827302U - Ultrasonic power supply for transducer cascade - Google Patents

Abstract

The utility model relates to an ultrasonic power supply for cascading transducers. The ultrasonic power supply includes a rectifier bridge, a filter circuit, a DC chopping circuit, a full-bridge inverter circuit, a first impedance stepless matching network, a second impedance Stepless matching network, first transducer, second transducer, matching network control circuit, voltage and current sampling circuit, frequency tracking circuit, power constant circuit. The matching network control circuit controls the matching inductance of the first and second stepless impedance matching networks connected to the inverter output circuit. The output voltage and current of the full-bridge inverter circuit pass through the sampling circuit and are connected to the frequency tracking circuit and the power constant circuit. The frequency tracking circuit controls the frequency of the full-bridge inverter, and the power constant circuit controls the output voltage of the DC chopper circuit. The combined effect of the frequency tracking circuit of the utility model and the first and second impedance stepless matching networks can ensure the normal operation of the cascaded transducers, and change the previous operation mode of single inverter and single transducer.

Description

An Ultrasonic Power Supply for Transducer Cascading

technical field

The utility model relates to the technical field of ultrasonic power supplies, in particular to an ultrasonic power supply for cascading transducers.

Background technique

The ultrasonic power supply is usually called the ultrasonic generating source, and its function is to convert electrical energy into a high-frequency alternating current signal that matches the ultrasonic transducer. The load of the ultrasonic power supply is the ultrasonic transducer, and the ultrasonic transducer has static capacitance. Therefore, when the ultrasonic transducer is used, it must have a corresponding inductive matching network to cooperate with the work of the ultrasonic transducer.

At present, the matching network used by the commonly used ultrasonic power supply is a single inductor or a T-shaped matching inductor. By changing the output frequency of the inverter, the effect of tracking the resonant frequency of the transducer is achieved. In this working mode, a single inverter power supply can only be operated with one transducer, so that the capacity of the power supply is limited by the power of the transducer.

Utility model content

The purpose of the utility model is to disclose an ultrasonic power supply for cascading transducers.

The utility model discloses an ultrasonic power supply for cascading transducers. The frequency tracking circuit controls the alternating current frequency output by the full-bridge inverter circuit to track the resonant frequency of the transducer. The matching network control circuit controls the first and second impedances. The level matching network is connected to the inverter output end of the ultrasonic power supply to match the size of the equivalent inductance, respectively to achieve the effect of fine-tuning the resonant frequency of the first and second branches where the first and second transducers are located, and to achieve the cascade operation of the transducers Effect.

The purpose of this utility model can adopt following technical scheme to realize:

An ultrasonic power supply for transducer cascading, which includes a rectifier bridge, a filter circuit, a DC chopper circuit, a full-bridge inverter circuit, a first impedance stepless matching network, a second impedance stepless matching network, a first Transducer, second transducer, matching network control circuit, voltage and current sampling circuit, frequency tracking circuit, power constant circuit; the first impedance stepless matching network consists of the first thyristor, the second thyristor, the first inductor, the second Composed of inductance; the second impedance stepless matching network is composed of the third thyristor, the fourth thyristor, the third inductor, and the fourth inductor; the first impedance stepless matching network is connected in parallel with the first transducer to form the first branch, and the second The impedance stepless matching network and the second transducer are connected in parallel to form the second branch; the first branch and the second branch are cascaded and then connected to the output end of the inverter bridge of the ultrasonic power supply; the matching network control circuit controls the first impedance stepless The duty cycle of the first thyristor driving signal and the second thyristor driving signal driving the first thyristor and the second thyristor in the stage matching network can control the size of the equivalent inductance of the first impedance stepless matching network connected to the inverter main circuit; The matching network control circuit can control the second impedance stepless matching network access by controlling the third thyristor driving signal and the duty ratio of the fourth thyristor driving signal driving the third thyristor and the fourth thyristor in the second impedance stepless matching network The size of the equivalent inductance of the inverter main circuit; the output voltage and current of the full-bridge inverter circuit pass through the sampling circuit, access the frequency tracking circuit and the power constant circuit, the frequency tracking circuit controls the inverter frequency of the full-bridge inverter circuit, and the power is constant The circuit controls the magnitude of the output voltage of the DC chopper circuit.

Further optimized, the matching network control circuit includes four identical thyristor drive signal generation circuits, which are respectively the first thyristor drive signal generation circuit, the second thyristor drive signal generation circuit, the third thyristor drive signal generation circuit, and the fourth thyristor drive signal generation circuit. Drive signal generation circuit. The positive terminals of the first and third thyristor driving signal generating circuits are connected to the output voltage sampling signal; the negative terminals of the second and fourth thyristor driving signal generating circuits are connected to the output voltage sampling signal. The negative terminals of the first and third thyristor driving signal generating circuits and the positive terminals of the second and fourth thyristor driving signal generating circuits are grounded. The first, second, third and fourth thyristor drive signal generating circuits respectively generate first, second, third and fourth thyristor drive signals. The first PI control signal can adjust the duty cycle of the first and second thyristor drive signals; the second PI control signal can adjust the duty cycle of the third and fourth thyristor drive signals.

Further, the matching network control circuit can control the equivalent inductance of the first impedance stepless matching network access circuit by controlling the first thyristor driving signal and the duty cycle of the second thyristor driving signal for driving the first thyristor and the second thyristor The magnitude, so that the first branch voltage and the first branch current of the first branch where the first transducer is located are in the same phase. The matching network control circuit can control the equivalent inductance of the second impedance stepless matching network access circuit by controlling the duty cycle of the third thyristor, the third thyristor driving signal of the third thyristor, and the fourth thyristor driving signal so that the second impedance stepless matching network is connected to the circuit. The second branch voltage and the second branch current of the second branch where the two transducers are located are in the same phase.

The described ultrasonic power supply for transducer cascading is characterized in that the voltage and current output by the full-bridge inverter circuit pass through the sampling signal obtained by the sampling circuit, and control the inverter of the full-bridge inverter circuit through the frequency tracking circuit. frequency, so that the output frequency of the full-bridge inverter circuit tracks the resonant frequency of the transducer.

The described ultrasonic power supply for transducer cascading is characterized in that the frequency tracking circuit controls the AC frequency output by the full-bridge inverter circuit to track the resonant frequency of the transducer; due to the influence of frequency drift, the first transducer , The resonant frequency of the second transducer has a slight difference, while the first impedance stepless matching network and the second impedance stepless matching network adjust the resonant frequency of the first branch and the second branch respectively, so that the first branch The first branch voltage and the first branch current have the same phase and the second branch voltage and the second branch current of the second branch have the same phase.

An ultrasonic power supply for cascading transducers, using inverter frequency tracking and impedance stepless matching network to achieve the purpose of transducer resonance. The first impedance stepless matching network and the second impedance stepless matching network respectively adjust the resonant frequencies of the first branch and the second branch where the first transducer and the second transducer are located to reach multiple inverters under one inverter. The purpose of working together with transducers has changed the previous working mode of ultrasonic power supply with single inverter and single transducer.

Compared with the prior art, the utility model has the following advantages:

The transducer cascaded ultrasonic power supply proposed by the utility model is different from the traditional ultrasonic power supply. The traditional ultrasonic power supply adopts a single inductance matching network and a T-shaped matching network, and its inductance value is constant and cannot be adjusted. The existing adjustable matching network It is also through the way of inductance switching, which adopts step adjustment, and the accuracy is limited. The traditional ultrasonic power supply only adjusts the output frequency of the full-bridge inverter circuit to achieve the purpose of frequency tracking. Due to the differences in the working environment, the resonant frequency drift of each transducer is also different during operation. Therefore, one power supply can only be connected to A transducer load.

The transducer cascaded ultrasonic power supply proposed by the utility model can be connected to the equivalent inductance of the main circuit by adjusting the first and second impedance stepless matching networks to achieve the first and second where the first and second transducers are located. The effect of fine-tuning the resonant frequency of the two branches. Under the common action of the frequency tracking circuit, the input voltage and current of the first and second transducers can achieve the effect of the same phase under the condition of the same inverter. It makes it possible for the transducers to operate in cascade under one inverter power supply, so that the capacity of the power supply is no longer limited by the power of the transducers.

Description of drawings

Figure 1 is a schematic diagram of the ultrasonic power supply for cascading transducers;

Fig. 2 is the connection diagram of cascade transducer;

Fig. 3 is a matching network control circuit diagram;

Fig. 4 is a thyristor drive signal generation circuit diagram;

Fig. 5 is a waveform diagram of the output voltage and current of the full-bridge inverter circuit and the current of the branches where the first transducer and the second transducer are located under psim simulation conditions.

FIG. 6 is a waveform diagram of the phase difference pulse indicating signal V15 and the phase difference voltage indicating signal V40.

Detailed ways

The implementation of the utility model will be further described below in conjunction with the accompanying drawings, but the implementation and protection of the utility model are not limited thereto.

As shown in Figure 1, an ultrasonic power supply for cascaded transducers includes a rectifier bridge, a filter circuit, a DC chopper circuit, a full-bridge inverter circuit, a first impedance stepless matching network TL1, and a second impedance stepless matching network. Stage matching network TL2, first transducer tran1, second transducer tran2, matching network control circuit, voltage and current sampling circuit, frequency tracking circuit, power constant circuit.

The connection diagram of the cascaded transducer is shown in FIG. 2 . The first impedance stepless matching network TL1 is composed of a first thyristor THY1 , a second thyristor THY2 , a first inductor L1 and a second inductor L2 . The second stepless impedance matching network TL2 is composed of a third thyristor THY3 , a fourth thyristor THY4 , a third inductor L3 and a fourth inductor L4 . The first stepless matching network TL1 is connected in parallel with the first transducer tran1 to form a first branch, and the second stepless impedance matching network TL2 is connected in parallel with the second transducer tran2 to form a second branch. The first branch and the second branch are cascaded and then connected to the output end of the full-bridge inverter circuit. The frequency tracking circuit controls the output frequency of the full-bridge inverter circuit, and the matching network control circuit controls the size of the equivalent inductance connected to the main circuit by the first stepless impedance matching network and the second stepless impedance matching network.

The frequency tracking circuit of this example works together with the impedance stepless matching network to achieve the purpose of cascading transducers. The connection diagram of the cascaded transducers is shown in Figure 2. The frequency tracking circuit makes the frequency of the output alternating current of the full-bridge inverter circuit track the resonant frequencies of the first transducer tran1 and the second transducer tran2. The matching network control circuit steplessly adjusts the size of the equivalent inductance of the first impedance stepless matching network TL1 and the second impedance stepless matching network TL2 connected to the main circuit, respectively reaching the first transducer tran1 and the second transducer The effect of tran2 stepless matching. When the first transducer tran1 and the second transducer tran2 have different frequency drifts, through the control of the matching network control circuit, the voltage of the first branch of the first branch where the first transducer tran1 is located, The currents of the first branch are in the same phase, and the voltage and current of the second branch of the second branch where the second transducer tran2 is located are in the same phase. Since the full-bridge inverter circuit can only track the resonant frequency of one ultrasonic transducer, the method of adjusting the impedance stepless matching network can make the voltage and current of the branch circuit where each transducer is located be in the same phase state. In this way, the operation mode of a single transducer of a single full-bridge inverter circuit in the traditional ultrasonic power supply has been changed. It makes it possible for the transducers to operate in cascade, and the capacity of the ultrasonic power supply is no longer limited by the power of the transducers. Fig. 5 is a waveform diagram of the output voltage and current of the full-bridge inverter circuit and the branch currents of the first transducer tran1 and the second transducer tran2 under psim simulation conditions. Among them, VP1 is the voltage waveform output by the full-bridge inverter circuit, V7 is the current waveform output by the full-bridge inverter circuit, V60 is the current waveform of the first branch, and V42 is the current waveform of the second branch. For the convenience of observation, the current in the figure is an enlarged waveform. It can be seen that the voltage VP1 and current V7 output by the full-bridge inverter, and the currents V60 and V42 of the branches where the first transducer tran1 and the second transducer tran2 are located are in the same phase state. The current output by the inverter is the sum of the currents of the two branches. Fig. 6 is a waveform diagram of the voltage indicating signal of the voltage and current phase difference of the branch where the first transducer tran1 and the second transducer tran2 are located under the psim simulation condition, V15 is the phase difference indicating signal of the first branch, and V40 is The phase difference indication signal of the second branch. It can be seen from the figure that V15 and V40 return to zero after 0.45S, that is, the first branch voltage and the first branch current have the same phase at this time, and the second branch voltage and the second branch current have the same phase.

The connection relationship of the matching network control circuit components of the present utility model is as follows:

As shown in Fig. 4, the positive input terminal pin 1 of the first comparator COMP5 is the positive input terminal of the thyristor driving signal generating circuit; the negative input terminal pin 2 of the first comparator COMP5 is the negative input terminal of the thyristor driving signal generating circuit. The output pin 27 of the first comparator COMP5 is connected to the negative input pin 5 of the first amplifier OP_AMP3 through the first resistor R20, and the output pin 27 of the first comparator COMP5 is connected to the drop of the first monostable trigger MONO3 Along trigger pin 23. The Q output terminal pin 24 of the first monostable trigger is connected to the base B1 of the first triode npn3, the Q non-output terminal of the first monostable trigger is suspended, and the rising edge trigger terminal is grounded. The collector C1 and the emitter E1 of the first triode are respectively connected to the negative input terminal pin 5 and the output terminal pin 7 of the first amplifier OP_AMP3, and the pins 5 and 7 are connected to the first capacitor C22. The positive input pin 6 of the first amplifier OP_AMP3 is grounded through the second resistor R21. The output terminal pin 7 of the first amplifier OP_AMP3 is connected to the negative input terminal pin 8 of the second amplifier OP_AMP5 through the third resistor R24, and the negative input terminal pin 8 of the second amplifier is connected to the output terminal pin 10 through the fourth resistor R28. The input terminal pin 9 is grounded after passing through five resistors R25, the output terminal pin 10 is connected to the positive input terminal pin 11 of the second comparator COMP7, and the output terminal pin 13 of the second comparator COMP7 is the output terminal of the thyristor drive signal generating circuit, which can be Generate thyristor drive signal. The negative input terminal pin 12 of the second comparator COMP7 is connected to an external PI control signal.

Claims (2)

1. An ultrasonic power supply for transducer cascading, characterized in that it comprises a rectifier bridge, a filter circuit, a DC chopper circuit, a full-bridge inverter circuit, a first impedance stepless matching network (TL1), a second impedance Stepless matching network (TL2), first transducer (tran1), second transducer (tran2), matching network control circuit, voltage and current sampling circuit, frequency tracking circuit, power constant circuit; first impedance stepless matching The network (TL1) is composed of the first thyristor (THY1), the second thyristor (THY2), the first inductor (L1), and the second inductor (L2); the second impedance stepless matching network (TL2) is composed of the third thyristor (THY3 ), the fourth thyristor (THY4), the third inductor (L3), and the fourth inductor (L4); the first impedance stepless matching network (TL1) is connected in parallel with the first transducer (tran1) to form the first branch, The second impedance stepless matching network (TL2) and the second transducer (tran2) are connected in parallel to form the second branch; the first branch and the second branch are cascaded and then connected to the output end of the inverter bridge of the ultrasonic power supply; the matching network The control circuit can control the first thyristor drive signal and the duty cycle of the second thyristor drive signal to drive the first thyristor (THY1) and the second thyristor (THY2) in the first impedance stepless matching network. The matching network (TL1) is connected to the equivalent inductance of the inverter main circuit; the matching network control circuit drives the third thyristor (THY3) and the fourth thyristor (THY4) in the second impedance stepless matching network to drive signal, the duty ratio of the fourth thyristor drive signal can control the size of the equivalent inductance of the second impedance stepless matching network (TL2) connected to the inverter main circuit; the output voltage and current of the full-bridge inverter circuit pass through the sampling circuit, A frequency tracking circuit and a power constant circuit are connected, the frequency tracking circuit controls the inverter frequency of the full-bridge inverter circuit, and the power constant circuit controls the output voltage of the DC chopper circuit. 2. A kind of ultrasonic power supply for cascading transducers according to claim 1, characterized in that the matching network control circuit includes four identical thyristor drive signal generation circuits, which are respectively the first thyristor drive signal generation circuit circuit, the second thyristor driving signal generating circuit, the third thyristor driving signal generating circuit, and the fourth thyristor driving signal generating circuit; the positive terminals of the first and third thyristor driving signal generating circuits are connected to the output voltage sampling signal; the second and the second The negative terminals of the four thyristor driving signal generating circuits are connected to the output voltage sampling signal; the negative terminals of the first and third thyristor driving signal generating circuits and the positive terminals of the second and fourth thyristor driving signal generating circuits are grounded; the first and second thyristor driving signal generating circuits are grounded; The first, second, third and fourth thyristor drive signals are respectively generated by the third and fourth thyristor drive signal generating circuits.