CN204065405U - Ultrasonic transmission/reception integrative control circuit - Google Patents

Abstract

The utility model discloses an ultrasonic transmitting and receiving integrated control circuit, which is characterized in that it comprises an ultrasonic transmitting circuit, an input end of the ultrasonic transmitting circuit receives a pulse signal, an output end of the ultrasonic transmitting circuit and an electric signal input end of an ultrasonic transducer The electrical signal output end of the ultrasonic transducer is connected to the signal amplification circuit through the absolute value change circuit, the output end of the signal amplification circuit is connected to the envelope detection circuit, and the output end of the envelope detection circuit is connected to the interrupt signal generation circuit. Its remarkable effects are: the circuit is simple, the measurement accuracy is high, the transmission power is adjustable, and an integrated ultrasonic transducer for transmitting and receiving is adopted, which is small in size, uses few components, low in cost and stable in performance.

Description

Ultrasonic transceiver integrated control circuit

technical field

The utility model relates to the technical field of ultrasonic distance measurement, in particular to an ultrasonic transceiver integrated control circuit. the

Background technique

Due to the strong directivity of ultrasonic waves, slow energy consumption, and long distances in the medium, ultrasonic waves are often used for close-range non-contact distance measurement, such as liquid level measurement, coal seam thickness measurement, robot positioning, and car anti-collision radar. , Auxiliary vision system and so on. The principle of ultrasonic ranging is: drive the ultrasonic transmitter to emit ultrasonic waves to obstacles, and start timing while emitting ultrasonic waves. When the ultrasonic waves encounter obstacles on the way to propagate, they will return immediately, and the returned ultrasonic waves (ie echo) will be sent by the ultrasonic receiver. Receive, and stop timing when receiving the reflected wave, and calculate the distance between the transmitting point and the obstacle according to the propagation speed of the ultrasonic wave in the air and the recorded time difference. the

Measuring distance by ultrasonic is generally fast, convenient, simple to calculate, easy to realize real-time control, and can meet the requirements of industrial practicality in terms of measurement accuracy, so it is widely used in modern industrial production processes. However, traditional ultrasonic distance measuring equipment has many shortcomings due to the use of a comparator with a fixed threshold to compare the output: low measurement accuracy; most of them do not use an integrated ultrasonic transducer for transmitting and receiving, resulting in large volume and high cost of ultrasonic distance measuring equipment. the

Utility model content

Aiming at the deficiencies of the prior art, the purpose of this utility model is to provide an ultrasonic transmitting and receiving integrated control circuit, which has high measurement accuracy, adopts an integrated transmitting and receiving ultrasonic transducer, and is small in size and low in cost. the

In order to achieve the above-mentioned purpose, the utility model describes a kind of ultrasonic transceiver integrated control circuit, its key lies in: comprising ultrasonic transmitting circuit, the input end of this ultrasonic transmitting circuit receives a pulse signal, the output end of ultrasonic transmitting circuit and the ultrasonic transducer The electrical signal input end is connected, the electrical signal output end of the ultrasonic transducer is connected with the signal amplification circuit through the absolute value change circuit, the output end of the signal amplification circuit is connected with an envelope detection circuit, and the output end of the envelope detection circuit is connected to There is an interrupt signal generation circuit;

The absolute value changing circuit includes a triode Q2, the base series capacitor C7 and the resistor R9 of the triode Q2 are connected to the electrical signal output end of the ultrasonic transducer, and the collector series resistor R3 and the resistor R2 of the triode Q2 are connected to 8V DC power supply, the emitter of the triode Q2 is grounded through the resistor R11, the collector of the triode Q2 is connected to the signal amplifying circuit through the capacitor C1, the base of the triode Q2 is also connected with the cathode of the Zener diode D3, and the The anode is grounded, and a resistor R7 is also connected between the collector and the base of the triode Q2;

The envelope detection circuit includes a Zener diode D1, the anode of the Zener diode D1 is connected to the output end of the signal amplification circuit, and the cathode of the Zener diode D1 is connected to the input end of the interrupt signal generating circuit via a resistor R5 Connected, the cathode of Zener diode D1 is also connected to ground through capacitor C5. the

The ultrasonic transmitting circuit is used to receive pulse signals sent by controllers such as single-chip microcomputers, and convert them into sine wave signals; the ultrasonic transducer is used to transmit ultrasonic signals to obstacles after being excited by sine wave signals, And it is used to receive the echo signal reflected by the obstacle; the absolute value change circuit is used to filter out the negative voltage part in the voltage signal; the signal amplification circuit is used to amplify the voltage signal output by the absolute value change circuit ; The envelope detection circuit is used to perform AM detection processing on the amplified signal; The interrupt signal generating circuit generates an interrupt signal according to the AM detected signal and outputs it to the controller. This circuit has high measurement accuracy, and adopts a transceiver integrated ultrasonic transducer, which is small in size, uses few components, low in cost and stable in performance. the

As a further description, the ultrasonic transmitting circuit includes a triode Q3, the base of the triode Q3 receives the pulse signal, the collector of the triode Q3 is connected to a 12V DC power supply after R12, the emitter of the triode Q3 is grounded, and the triode Q3 The collector of the ultrasonic transducer is connected to the electrical signal input end of the ultrasonic transducer. the

As a further description, the signal amplifying circuit includes an operational amplifier U1, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the absolute value changing circuit after the capacitor C6 and the resistor R4 in turn, and the common connection between the capacitor C6 and the resistor R4 The connection terminal is also grounded through a resistor R8, the positive phase input terminal of the operational amplifier U1 is connected to an 8V DC power supply, the output terminal of the operational amplifier U1 is connected to the anode of the diode D1 through a capacitor C3, and the anode of the diode D1 is also connected to the diode D1. The cathode of D2 is connected, the anode of diode D2 is grounded, a resistor R6 is connected in series between the output terminal of the operational amplifier U1 and the inverting input terminal, and the output terminal of the operational amplifier U1 is connected to the capacitor C6 and the resistor R4 via the capacitor C2 public end. the

As a further description, the interrupt signal generation circuit includes a triode Q1, the base of the triode Q1 is connected in series with the output terminal of the envelope detection circuit with a series resistor R5, and the collector series resistor R1 of the triode Q1 is connected with a 3.3V DC power supply , the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 outputs an interrupt signal. the

As a further description, in order to obtain a stable ultrasonic signal, the pulse signal uses a square wave signal with a frequency of 40 kHz. the

The remarkable effects of the utility model are: the circuit is simple, the measurement precision is high, the transmission power is adjustable, and an integrated ultrasonic transducer for transmitting and receiving is adopted, the volume is small, the components are few, the cost is low, and the performance is stable. the

Description of drawings

Fig. 1 is a schematic circuit diagram of the utility model. the

Detailed ways

The specific embodiment and working principle of the present utility model will be described in further detail below in conjunction with the accompanying drawings. the

As shown in Figure 1, a kind of ultrasonic transceiver integrated control circuit includes an ultrasonic transmitting circuit, the input end of the ultrasonic transmitting circuit receives a pulse signal, the output end of the ultrasonic transmitting circuit is connected with the electrical signal input end of the ultrasonic transducer, the The electrical signal output end of the ultrasonic transducer is connected to the signal amplifying circuit through an absolute value change circuit, the output end of the signal amplifying circuit is connected with an envelope detection circuit, and the output end of the envelope detection circuit is connected with an interrupt signal generating circuit;

The ultrasonic transmitting circuit includes a triode Q3, the base of the triode Q3 is connected in series with R15 to receive the pulse signal, the collector of the triode Q3 is connected to a 12V DC power supply after R12, the emitter of the triode Q3 is grounded, and the collector of the triode Q3 The electrodes are connected to the electrical signal input end of the ultrasonic transducer;

The absolute value changing circuit includes a triode Q2, the base series capacitor C7 and the resistor R9 of the triode Q2 are connected to the electrical signal output end of the ultrasonic transducer, and the collector series resistor R3 and the resistor R2 of the triode Q2 are connected to 8V DC power supply, the emitter of the triode Q2 is grounded through the resistor R11, the collector of the triode Q2 is connected to the signal amplifying circuit through the capacitor C1, the base of the triode Q2 is also connected with the cathode of the Zener diode D3, and the The anode is grounded, and a resistor R7 is also connected between the collector and the base of the triode Q2;

The signal amplifying circuit includes an operational amplifier U1, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the absolute value changing circuit after the capacitor C6 and the resistor R4 successively, and the common connection end of the capacitor C6 and the resistor R4 is also connected through a resistor R8 is grounded, the positive-phase input terminal of the operational amplifier U1 is connected to an 8V DC power supply, the output terminal of the operational amplifier U1 is connected to the anode of the diode D1 through a capacitor C3, and the anode of the diode D1 is also connected to the cathode of the diode D2. The anode of the diode D2 is grounded, and a resistor R6 is connected in series between the output terminal of the operational amplifier U1 and the inverting input terminal, and the output terminal of the operational amplifier U1 is connected to the common terminal of the capacitor C6 and the resistor R4 through the capacitor C2;

The envelope detection circuit includes a Zener diode D1, the anode of the Zener diode D1 is connected to the output end of the signal amplification circuit, and the cathode of the Zener diode D1 is connected to the input end of the interrupt signal generating circuit via a resistor R5 Connected, the cathode of Zener diode D1 is also grounded after capacitor C5;

The interrupt signal generating circuit includes a triode Q1, the base of the triode Q1 is connected to the output terminal of the envelope detection circuit after the base series resistor R5, and the collector string resistor R1 of the triode Q1 is connected to a 3.3V DC power supply after the transistor Q1. The pole is grounded, and the collector of the transistor Q1 outputs an interrupt signal. the

The ultrasonic transmitting circuit is used to receive the pulse signal sent by the single-chip microcomputer and convert it into a sine wave signal; the ultrasonic transducer is used to transmit an ultrasonic signal to an obstacle after being excited by a sine wave signal, and is used for receiving the echo signal reflected by the obstacle; the absolute value changing circuit is used to filter out the negative voltage part in the voltage signal; the signal amplifying circuit is used to amplify the voltage signal output by the absolute value changing circuit; the The envelope detection circuit is used to perform AM detection processing on the amplified signal; the interrupt signal generation circuit generates an interrupt signal according to the AM detected signal and outputs it to the controller. the

Preferably, the pulse signal in this embodiment adopts a square wave signal with a frequency of 40 kHz. the

working principle:

As shown in Figure 1, the CSB is connected to the electrical signal input terminal of the ultrasonic transducer, the IN terminal is used to receive the square wave with a fixed frequency of 40kHz generated by the single-chip microcomputer, and the OUT terminal is the interrupt signal output terminal, which is usually used as the interrupt input of the single-chip microcomputer;

Ultrasonic emission: a square wave pulse signal with a frequency of 40kHz drives the triode Q3, and the voltage above PS-12V is applied to the ultrasonic transducer to emit ultrasonic waves at a switching frequency of 40kHz; in actual use, if a longer detection range is required, You can increase the PS-12V and adjust the R12 current limit at the same time;

Ultrasonic reception: Since the echo signal generated may be 12V the strongest, it is obviously not possible to directly enter the microcontroller for processing. Therefore, for the echo signal, the capacitor C7 is used for direct blocking processing to obtain positive and negative echo signals; then The absolute value change circuit is composed of transistor Q2, resistor R7, and resistor R11. When the signal added to the base of transistor Q2 is negative, it is clamped to -0.7V by D3, so that transistor Q2 stops, and the voltage of the collector of transistor Q2 is positive, the transistor Q2 works in the switch mode, thereby realizing the change of the absolute value of the echo signal; then the ideal operational amplifier U1, capacitor C2, capacitor C6, resistor R8, capacitor C3, and Zener diode D2 form a signal amplification circuit to complete the The echo signal waveform is filtered and the waveform is shaped; then the envelope detection is performed through the Zener diode D1 and the capacitor C5; finally, the triode Q1 is driven to output an interrupt signal to the single-chip microcomputer, and the single-chip microcomputer is based on the time difference between sending the ultrasonic signal and receiving the interrupt signal, combined with the sound Propagation speed, so as to calculate the distance between the ultrasonic transmitter and the obstacle. the

Claims (5)

1. a ultrasonic transmission/reception integrative control circuit, it is characterized in that: comprise ultrasonic transmit circuit, the input end of this ultrasonic transmit circuit receives a pulse signal, the output terminal of ultrasonic transmit circuit is connected with the electric signal input end of ultrasonic transducer, the electrical signal of this ultrasonic transducer is connected with signal amplification circuit by absolute value varying circuit, the output terminal of this signal amplification circuit is connected with envelope detection circuit, and the output terminal of this envelope detection circuit is connected with look-at-me generative circuit;

Described absolute value varying circuit comprises triode Q2, base stage serial capacitors C7 and the electrical signal being connected described ultrasonic transducer after resistance R9 of this triode Q2,8V direct supply is connect after the collector crosstalk resistance R3 and resistance R2 of triode Q2, the emitter of triode Q2 is through resistance R11 ground connection, the collector of triode Q2 accesses in described signal amplification circuit through electric capacity C1, the base stage of triode Q2 is also connected with the negative electrode of voltage stabilizing diode D3, the plus earth of voltage stabilizing diode D3, is also connected with resistance R7 between the collector and base stage of triode Q2;

Described envelope detection circuit comprises voltage stabilizing diode D1, the anode of this voltage stabilizing diode D1 is connected with the output terminal of described signal amplification circuit, the negative electrode of this voltage stabilizing diode D1 is connected with the input end of described look-at-me generative circuit through resistance R5, and the negative electrode of voltage stabilizing diode D1 is also through electric capacity C5 ground connection.

2. ultrasonic transmission/reception integrative control circuit according to claim 1, it is characterized in that: described ultrasonic transmit circuit comprises triode Q3, the base stage of this triode Q3 receives described pulse signal, the collector of triode Q3 connects 12V direct supply after R12, the grounded emitter of triode Q3, the collector of triode Q3 connects the electric signal input end of described ultrasonic transducer.

3. ultrasonic transmission/reception integrative control circuit according to claim 1, it is characterized in that: described signal amplification circuit comprises operational amplifier U1, the anti-phase of this operational amplifier U1 enters to hold the output terminal connecing described absolute value varying circuit successively after electric capacity C6 and resistance R4, the public connecting end of electric capacity C6 and resistance R4 is also through resistance R8 ground connection, the normal phase input end of described operational amplifier U1 connects 8V direct supply, the output terminal of described operational amplifier U1 is connected with the anode of described diode D1 through electric capacity C3, the anode of diode D1 is also connected with the negative electrode of diode D2, the plus earth of diode D2, resistance R6 is also serially connected with between the output terminal of described operational amplifier U1 and inverting input, the output terminal of described operational amplifier U1 connects the common port of electric capacity C6 and resistance R4 through electric capacity C2.

4. ultrasonic transmission/reception integrative control circuit according to claim 1, it is characterized in that: described look-at-me generative circuit comprises triode Q1, be connected with the output terminal of described envelope detection circuit after the base series resistor R5 of triode Q1,3.3V direct supply is connect after the collector crosstalk resistance R1 of triode Q1, the grounded emitter of triode Q1, the collector of triode Q1 exports look-at-me.

5. ultrasonic transmission/reception integrative control circuit according to claim 1 and 2, is characterized in that: described pulse signal adopts frequency to be the square-wave signal of 40kHz.