Piezoelectric ceramic drive circuit

Abstract

The present invention discloses a piezoelectric ceramic driving circuit, including a stacked adjustable DC power supply circuit, an adjustable pulse signal circuit and a gate control circuit; the stacked adjustable DC power supply circuit is used to amplify the DC output voltage, the adjustable pulse signal circuit is used to provide an adjustable driving signal, and the gate control circuit drives the piezoelectric ceramic ring by controlling the switch of the high-voltage excitation pulse, and the stacked adjustable DC power supply circuit, the adjustable pulse signal circuit and the gate control circuit act on the piezoelectric ceramic ring together. The piezoelectric ceramic driving circuit of the present invention has the characteristics of simple structure and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit control, and in particular relates to a piezoelectric ceramic drive circuit. Background Art

[0002] As an important material that is sensitive to force, electricity, and light, piezoelectric ceramics have been widely used in electronics such as sensors and micro-displacers. In particular, the inverse piezoelectric effect of piezoelectric ceramics, when the piezoelectric ceramic material is placed in an external electric field, the piezoelectric body generates corresponding stress and strain phenomena while polarizing to work, which can be applied to liquid cooling systems or other trace liquid delivery devices in various micro-mechanical electronic systems. At present, the piezoelectric ceramic driving power supply is mainly charge-driven. The charge-driven power supply uses a current source instead of a voltage source, and a special charge amplifier needs to be designed. In addition, its low-frequency characteristics are poor and there is a zero drift defect. Therefore, it is necessary to design a simple and low-cost voltage-type driving circuit to drive the piezoelectric ceramic to work normally. Summary of the invention

[0003] The purpose of the present invention is to provide a piezoelectric ceramic driving circuit which has the characteristics of simple structure and low cost.

[0004] The technical solution adopted by the present invention is a piezoelectric ceramic driving circuit, including a stacked adjustable DC power supply circuit, an adjustable pulse signal circuit and a gate control circuit; the stacked adjustable DC power supply circuit is used to amplify the DC output voltage, the adjustable pulse signal circuit is used to provide an adjustable driving signal, and the gate control circuit drives the piezoelectric ceramic ring by controlling the switch of the high-voltage excitation pulse. The stacked adjustable DC power supply circuit, the adjustable pulse signal circuit and the gate control circuit act on the piezoelectric ceramic ring together.

[0005] The present invention is also characterized in that:

[0006] The stacked adjustable DC power supply circuit includes at least 5 identical circuits connected in series, each circuit includes a transformer unit, a rectifier unit, a voltage regulator unit and a voltage amplification unit; the mains is connected to the input end of the transformer unit, and the output end of the transformer unit is connected to the input end of the rectifier unit, which is used to transform the 220V mains power and convert the AC current into a DC current; the output end of the rectifier unit is connected to the input end of the voltage regulator unit, which is used to stabilize the output voltage; the output end of the voltage regulator unit is connected to the input end of the voltage amplification unit, and the output voltage is amplified through the stacked structure circuit;

[0007] The adjustable pulse signal circuit includes a pulse generating unit and a regulating unit; the input end of the pulse generating unit is connected to an external power supply for generating a pulse signal, and the output end of the pulse generating unit is connected to the input end of the regulating unit for providing an adjustable driving signal; the output end of the voltage amplifying unit is connected to a gate control circuit, and the gate control circuit is connected to the output end of the regulating unit.

[0008] The transformer output end of the transformer unit is respectively connected to the two AC input ends of the bridge rectifier of the rectifier unit, and the negative electrode of the output end of the bridge rectifier is connected to the negative electrode of capacitor C1, capacitor C2, resistor R2, negative electrode of capacitor C3, and negative electrode of capacitor C4.

[0009] The DC output end of the bridge rectifier of the rectifier unit is connected to the input end of the voltage stabilizing unit after filtering. The filtering element is composed of a resistor R1 and a capacitor C1 in parallel. The input end of the voltage stabilizing element U1 of the voltage stabilizing unit is connected with a capacitor C2. The output end of the voltage stabilizing element U1 is connected to a resistor R3, a positive electrode of a diode D1, a negative electrode of a diode D3, a capacitor C4, a resistor R18 of an adjustable pulse signal circuit and an emitter of a transistor Q2. The adjustment end ADJ of the voltage stabilizing unit is connected to a resistor R2, a resistor R3, a positive electrode of a capacitor C3 and a positive electrode of a diode D3.

[0010] The capacitors C4, C8, C15, C20 and C25 of the five circuits are connected in series in sequence, and the cathode of the capacitor C25 is connected to the anode of the diode D14 and then grounded.

[0011] The pulse generating unit includes a pulse element U3 connected to the regulating circuit, the regulating resistor R5 and the pin RST are respectively connected to the pin VCC, the other end of the regulating resistor R5 is respectively connected to the resistor R6 and the pin DIS, the other end of the resistor R6 is respectively connected to one end of the capacitor C10, the pin THR and the pin TRI, the other end of the capacitor C10 is respectively connected to one end of the capacitor C11 and the pin GND, the other end of the capacitor C11 is connected to the pin CON, the output end of the pulse generating unit is connected to one end of the resistor R7 and one end of the capacitor C9, the positive electrode of the diode D7 is connected to the other end of the resistor R7, and the other end of the capacitor C9 is connected to the other end of the resistor R10.

[0012] The control unit includes a pulse element U5 connected to the control circuit. One end of the control resistor R10 is respectively connected to the positive electrode of the diode D7 and the pin TRI, and the other end is respectively connected to the negative electrode of D7, one end of the resistor R15, the pin RST and the pin VCC. The other end of the resistor R15 is respectively connected to one end of the capacitor C16, the pin DIS and the pin THR. The other end of the capacitor C16 is respectively connected to one end of the capacitor C21 and the pin GND, and the other end of the capacitor C21 is connected to the pin CON.

[0013] The gate control circuit includes a transistor Q1 and a transistor Q2 connected to each other;

[0014] The output end of the pulse element U5 is connected to one end of the resistor R16, the other end of the resistor R16 is connected to one end of the resistor R14 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R14 are both grounded, the collector of the transistor Q1 is connected to one end of the resistor R19, the other end of the resistor R19 is respectively connected to the other end of the resistor R18 and the base of the transistor Q2, the collector of the transistor Q2 is respectively connected to the cathode of the diode D14 and one end of the piezoelectric ceramic ring, the other end of the piezoelectric ceramic ring and the anode of the diode D14 and the cathode output end of the stacked adjustable DC power supply circuit are all grounded.

[0015] The beneficial effects of the present invention are:

[0016] The piezoelectric ceramic driving circuit of the present invention comprises a stacked adjustable DC power supply circuit and an adjustable pulse signal circuit, which can realize the adjustment of the driving signal voltage amplitude, pulse width and pulse frequency; the piezoelectric ceramic driving circuit of the present invention utilizes a gate circuit to connect the stacked adjustable DC power supply circuit with the adjustable pulse signal circuit, realizes the control of the adjustable DC power supply by the low-voltage pulse signal, and thus outputs a high-voltage driving signal with adjustable amplitude, pulse width and frequency; the piezoelectric ceramic driving circuit of the present invention has high driving power efficiency, low heat generation, simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the piezoelectric ceramic driving circuit of the present invention;

[0018] Figure 2 is a schematic diagram of a piezoelectric ceramic driving circuit of the present invention;

[0019] Figure 3 It is a structural schematic diagram of an adjustable pulse signal circuit in a piezoelectric ceramic driving circuit of the present invention;

[0020] Figure 4 It is a waveform diagram of simulation results of a stacked adjustable DC power supply circuit in a piezoelectric ceramic drive circuit of the present invention;

[0021] Figure 5 It is a waveform diagram of simulation results of the adjustable pulse signal circuit in the piezoelectric ceramic drive circuit of the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The piezoelectric ceramic driving circuit of the present invention has a structure as follows Figure 1 , 2As shown, it includes a stacked adjustable DC power supply circuit, an adjustable pulse signal circuit and a gate control circuit; the stacked adjustable DC power supply circuit is used to amplify the DC output voltage, the adjustable pulse signal circuit is used to provide an adjustable drive signal, and the gate control circuit drives the piezoelectric ceramic ring by controlling the switch of the high-voltage excitation pulse. The stacked adjustable DC power supply circuit, the adjustable pulse signal circuit and the gate control circuit act on the piezoelectric ceramic ring together.

[0024] Preferably, the stacked adjustable DC power supply circuit includes at least 5 identical circuits connected in series, each circuit includes a transformer unit, a rectifier unit, a voltage regulator unit and a voltage amplification unit; the mains is connected to the transformer input end, and the transformer output end is connected to the rectifier input end, which is used to transform the 220V mains into a DC current; the rectifier output end is connected to the voltage regulator input end, which is used to stabilize the output voltage; the voltage regulator output end is connected to the voltage amplification input end, and the output voltage is amplified by the stacked structure circuit;

[0025] The adjustable pulse signal circuit includes a pulse generating unit and a regulating unit; the input end of the pulse generating unit is connected to an external power supply for generating a pulse signal, and the output end of the pulse generating unit is connected to the input end of the regulating unit for providing an adjustable driving signal; the output end of the voltage amplifying unit is connected to a gate control circuit, and the gate control circuit is connected to the output end of the regulating unit.

[0026] Preferably, the transformer output end of the transformer unit is respectively connected to the two AC input ends of the bridge rectifier of the rectifier unit, and the negative electrode of the output end of the bridge rectifier is connected to the negative electrode of capacitor C1, capacitor C2, resistor R2, negative electrode of capacitor C3, and negative electrode of capacitor C4.

[0027] Preferably, the DC output end of the bridge rectifier of the rectification unit is connected to the input end of the voltage stabilizing unit after filtering, the filtering element is composed of a resistor R1 and a capacitor C1 in parallel, the input end of the voltage stabilizing element U1 of the voltage stabilizing unit is connected with a capacitor C2, the output end of the voltage stabilizing element U1 is connected to a resistor R3, a positive electrode of a diode D1, a negative electrode of a diode D3, a capacitor C4, a resistor R18 of an adjustable pulse signal circuit and an emitter of a transistor Q2, and the adjustment end ADJ of the voltage stabilizing unit is connected to a resistor R2, a resistor R3, a positive electrode of a capacitor C3 and a positive electrode of a diode D3.

[0028] The connection method of the variable resistor R2 in the voltage stabilizing unit is not restricted, and the ratio of the variable resistor R2 to the fixed resistor R3 is 0 to 28.6, which can work normally.

[0029] Preferably, the capacitors C4, C8, C15, C20 and C25 of the five circuits are connected in series in sequence, and the cathode of the capacitor C25 is connected to the anode of the diode D14 and then grounded.

[0030] Preferably, if Figure 3As shown, the pulse generating unit includes a pulse element U3 connected to the regulating circuit, the regulating resistor R5 and the pin RST are respectively connected to the pin VCC, the other end of the regulating resistor R5 is respectively connected to the resistor R6 and the pin DIS, the other end of the resistor R6 is respectively connected to one end of the capacitor C10, the pin THR and the pin TRI, the other end of the capacitor C10 is respectively connected to one end of the capacitor C11 and the pin GND, the other end of the capacitor C11 is connected to the pin CON, the output end of the pulse generating unit is connected to one end of the resistor R7 and one end of the capacitor C9, the positive electrode of the diode D7 is connected to the other end of the resistor R7, and the other end of the capacitor C9 is connected to the other end of the resistor R10.

[0031] Preferably, the control unit includes a pulse element U5 connected to the control circuit, one end of the control resistor R10 is respectively connected to the positive electrode of the diode D7 and the pin TRI, and the other end is respectively connected to the negative electrode of D7, one end of the resistor R15, the pin RST and the pin VCC, the other end of the resistor R15 is respectively connected to one end of the capacitor C16, the pin DIS and the pin THR, the other end of the capacitor C16 is respectively connected to one end of the capacitor C21 and the pin GND, and the other end of the capacitor C21 is connected to the pin CON.

[0032] Resistor R7 and diode D7 are added to suppress sharp pulses at the high level.

[0033] Preferably, the gate control circuit includes a transistor Q1 and a transistor Q2 connected to each other; the output end of the pulse element U5 is connected to one end of the resistor R16, the other end of the resistor R16 is connected to one end of the resistor R14 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R14 are both grounded, the collector of the transistor Q1 is connected to one end of the resistor R19, the other end of the resistor R19 is respectively connected to the other end of the resistor R18 and the base of the transistor Q2, the collector of the transistor Q2 is respectively connected to the cathode of the diode D14 and one end of the piezoelectric ceramic ring, the other end of the piezoelectric ceramic ring is respectively grounded to the anode of the diode D14 and the cathode output end of the stacked adjustable DC power supply circuit.

[0034] The piezoelectric ceramic driving circuit of the present invention has the following working principle:

[0035] The piezoelectric ceramic drive circuit is powered by a 220V power supply. The mains power is converted into direct current after passing through five transformer units and a rectifier unit. After being filtered by resistor R1 and capacitor C1, it enters the voltage stabilizing unit. The voltage stabilizing unit adjusts the output voltage amplitude by adjusting its external variable resistor. In order to reduce the ripple voltage on the variable resistor, a capacitor C3 is connected in parallel to it. When the output is open, the capacitor C3 discharges to the adjustment end of the voltage regulator and reverses the emitter junction of the adjustment end. By connecting a diode D3 in parallel to the resistor R3, a discharge loop is provided to protect the voltage regulator. The capacitor C2 is used to offset the inductance effect when the input line is long to prevent the circuit from self-oscillation. The capacitor C4 is used to eliminate high-frequency noise in the output voltage so as to output a larger pulse current at the same time. When the input end is disconnected, the capacitor C4 will discharge from the output end of the voltage regulator (voltage stabilizing element U1) to the voltage regulator, which is easy to damage the voltage regulator. Therefore, the voltage regulator is protected by a cross-connected diode D1. The DC-DC conversion circuit provides a 12V DC power supply to power the adjustable pulse signal circuit composed of the NE555 timer (pulse elements U3, U5), differential circuit (regulation circuit), etc. The pulse element U3 and the external elements R5, R6, C10, C11 charge and discharge the capacitor C10, so that the circuit generates a self-excited rectangular wave output, and the external capacitor C11 is used for filtering to prevent signal interference. Subsequently, the differential circuit converts the rectangular wave pulse signal into a sharp pulse signal, and U5, R15, and C16 shape the pulse signal after the differential circuit. The two transistors Q1 and Q2 are used as a pair of transistors to realize the switching control of the low-voltage adjustable pulse signal on the high-voltage signal, and finally realize the driving of the piezoelectric ceramic ring.

[0036] The present invention uses a driving mode with adjustable voltage (6V-333V) amplitude and pulse signal and indirectly changes the high-voltage signal using a low-voltage pulse signal, and further changes the working state of the piezoelectric ceramic ring through a gate control circuit.

[0037] Simulation experiment:

[0038] Conduct circuit simulation experiments in Multisim 13 software. Figure 4 It is a simulation test waveform diagram of the stacked adjustable DC power supply circuit of the present invention, in order to test the maximum output voltage of the piezoelectric ceramic drive circuit; Figure 5 This is a simulation test waveform diagram of the adjustable pulse signal circuit of the present invention, in order to verify the feasibility of the adjustable pulse signal circuit to output a high-voltage adjustable signal.

[0039] Depend on Figure 4It can be seen that the stacked adjustable DC power supply circuit can generate a high voltage of 330V, which means that the stacked adjustable DC power supply circuit can effectively convert the mains power into DC power and boost the voltage to meet the driving voltage of the piezoelectric ceramic ring, and the requirement of adjustable output voltage amplitude can be achieved by adjusting the variable resistance value in the stacked adjustable DC power supply circuit; Figure 5 It can be seen that the adjustable pulse signal circuit can generate 6 pulse signals with a pulse width of 10μs in 1s, and the adjustable pulse signal circuit can change the output signal characteristics of the high-voltage output voltage by changing the pulse width and frequency of the low-voltage pulse signal, thereby realizing the output function of the low-voltage signal regulating the high-voltage signal.

Claims

1. A piezoelectric ceramic driving circuit, characterized in that: It includes a stacked adjustable DC power supply circuit, an adjustable pulse signal circuit and a gate control circuit; the stacked adjustable DC power supply circuit is used to amplify the DC output voltage, the adjustable pulse signal circuit is used to provide an adjustable drive signal, and the gate control circuit drives the piezoelectric ceramic ring by controlling the switch of the high-voltage excitation pulse, and the stacked adjustable DC power supply circuit, the adjustable pulse signal circuit and the gate control circuit act on the piezoelectric ceramic ring together; The stacked adjustable DC power supply circuit includes at least 5 identical circuits connected in series, each of which includes a transformer unit, a rectifier unit, a voltage regulator unit and a voltage amplification unit; the mains is connected to the transformer input end, and the transformer output end is connected to the rectifier input end, which is used to transform the 220V mains power and convert the AC current into a DC current; the rectifier output end is connected to the voltage regulator input end, which is used to stabilize the output voltage; the voltage regulator output end is connected to the voltage amplification input end, and the output voltage is amplified by the stacked structure circuit; The adjustable pulse signal circuit includes a pulse generating unit and a control unit; the input end of the pulse generating unit is connected to an external power supply for generating a pulse signal, and the output end of the pulse generating unit is connected to the input end of the control unit for providing an adjustable driving signal; the output end of the voltage amplifying unit is connected to a gate control circuit, and the gate control circuit is connected to the output end of the control unit; The transformer output end of the transformer unit is respectively connected to the two AC input ends of the bridge rectifier of the rectifier unit, and the negative electrode of the output end of the bridge rectifier is connected to the negative electrode of capacitor C1, capacitor C2, resistor R2, negative electrode of capacitor C3, and negative electrode of capacitor C4; The DC output end of the bridge rectifier of the rectification unit is connected to the input end of the voltage stabilization unit after filtering, the filtering element is composed of a resistor R1 and a capacitor C1 in parallel, the input end of the voltage stabilization element U1 of the voltage stabilization unit is connected to a capacitor C2, the output end of the voltage stabilization element U1 is connected to a resistor R3, a positive electrode of a diode D1, a negative electrode of a diode D3, a capacitor C4, a resistor R18 of an adjustable pulse signal circuit and an emitter of a transistor Q2, and the adjustment end ADJ of the voltage stabilization unit is connected to a resistor R2, a resistor R3, a positive electrode of a capacitor C3, and a positive electrode of a diode D3; The pulse generating unit includes a pulse element U3 connected to the regulating circuit, a regulating resistor R5 and a pin RST are respectively connected to the pin VCC, the other end of the regulating resistor R5 is respectively connected to the resistor R6 and the pin DIS, the other end of the resistor R6 is respectively connected to one end of the capacitor C10, the pin THR and the pin TRI, the other end of the capacitor C10 is respectively connected to one end of the capacitor C11 and the pin GND, the other end of the capacitor C11 is connected to the pin CON, the output end of the pulse generating unit is connected to one end of the resistor R7 and one end of the capacitor C9, the positive electrode of the diode D7 is connected to the other end of the resistor R7, and the other end of the capacitor C9 is connected to the other end of the resistor R10; The control unit includes a pulse element U5 connected to the control circuit, one end of the control resistor R10 is respectively connected to the positive electrode of the diode D7 and the pin TRI, and the other end is respectively connected to the negative electrode of D7, one end of the resistor R15, the pin RST and the pin VCC, the other end of the resistor R15 is respectively connected to one end of the capacitor C16, the pin DIS and the pin THR, the other end of the capacitor C16 is respectively connected to one end of the capacitor C21 and the pin GND, and the other end of the capacitor C21 is connected to the pin CON; The gate control circuit includes a transistor Q1 and a transistor Q2 connected to each other; The output end of the pulse element U5 is connected to one end of the resistor R16, the other end of the resistor R16 is connected to one end of the resistor R14 and the base of the transistor Q1, the emitter of the transistor Q1 and the other end of the resistor R14 are both grounded, the collector of the transistor Q1 is connected to one end of the resistor R19, the other end of the resistor R19 is respectively connected to the other end of the resistor R18 and the base of the transistor Q2, the collector of the transistor Q2 is respectively connected to the negative electrode of the diode D14 and one end of the piezoelectric ceramic ring, the other end of the piezoelectric ceramic ring is grounded to the positive electrode of the diode D14 and the negative output end of the stacked adjustable DC power supply circuit.

2. The piezoelectric ceramic driving circuit according to claim 1, characterized in that: The capacitors C4, C8, C15, C20 and C25 of the five circuits are connected in series in sequence, and the cathode of the capacitor C25 is connected to the anode of the diode D14 and then grounded.

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