CN203405445U - Miniature ultrasonic bubble detector control circuit - Google Patents

Abstract

The utility model relates to a miniature ultrasonic bubble detector control circuit. The control circuit is composed of an ultrasonic transmitting end drive part, an ultrasonic receiving end signal amplification filter part and a signal analog-digital conversion part. The ultrasonic transmitting end drive part is supplied by an active crystal oscillator. The ultrasonic receiving end signal amplification filter part is composed of a superspeed voltage comparator and a resistance-capacitance low-pass filter. The signal analog-digital conversion part is completed by the superspeed voltage comparator. Amplification, rectification and analog-digital conversion of received ultrasonic pulses are all completed by the voltage comparator, so that operations of the receiving end circuit can be completed only by one double-voltage comparator chip, the number of elements used in the circuit is reduced, and the size of the circuit is lowered.

Description

Miniature ultrasonic gas bubble detection control circuit

Affiliated technical field

The utility model relates to a kind of ultrasonic bubble detector control circuit of surveying the control circuit, particularly a kind of micro volume of the sensing device of bubble in pipeline liquid.

Background technology

The ultrasonic detector control circuit of bubble in existing detection pipeline liquid, its principle is the ultrasonic signal intensity of crossing pipeline by detecting transmission, and changes to judge in pipeline, whether have bubble according to the voltage signal after conversion.Its receiving terminal circuit adopts rectifying and wave-filtering or signal operation amplification filtering mostly, then the method that filtered signal carries out signal processing has been provided to bubble-free judgement output.Its common feature is all to need more element, thereby makes detector have that control system is complicated, volume is difficult to dwindle, signal response time long, high in cost of production shortcoming.

Summary of the invention

The defect existing in order to overcome prior art, the utility model patent provides a kind of hypomegetic ultrasonic bubble detector control circuit, and the element of its use is few, volume is little, system simple and stable, signal response speed are fast, is convenient to be packaged into small modules.

Miniature ultrasonic gas bubble detection control circuit described in the utility model is comprised of the driving of ultrasound wave transmitting terminal, ultrasound wave receiving end signal amplification filtering, signal mode number conversion three partial circuits.Ultrasound wave transmitting terminal drive part is provided by active crystal oscillator; Ultrasound wave receiving end signal amplification filtering part is comprised of hypervelocity voltage comparator and rc low pass filter; Signal digital-to-analogue conversion portion is completed by hypervelocity voltage comparator.Active crystal oscillator output terminal is connected with ultrasonic transducer transmitting terminal.Hypervelocity voltage comparator is comprised of comparer 1 and 2 two comparers of comparer, ultrasonic transducer receiving end is connected with comparer 1 input anode, comparer 1 output is connected with comparer 2 input anode by rc low pass filter, and the input cathode of comparer 1 and comparer 2 is connected with series connection divider resistance respectively.The ultrasound wave transmission frequency of this miniature ultrasonic gas bubble detection control circuit and ultrasound wave receive frequency are between 1MHz to 5MHz.

In order to reduce control circuit plate bulk, in the situation that control effect is constant, use the element of minimum number.The utility model partly utilizes voltage comparator directly the Weak Ultrasonic wave impulse receiving to be converted to digital pulse signal at receiving end, has saved traditional rectification circuit and operational amplifier.By passing through again another voltage comparator analog-to-digital conversion process after digital pulse signal filtering, signal is converted to digital high or low level, without logical circuits such as Sheffer stroke gates.The utility model completes by voltage comparator the amplification of the ultrasonic pulse receiving, rectification, analog to digital conversion, thereby receiving terminal circuit only can be completed with two voltage comparator chips, reduce the quantity that element is used, simplified system complexity.Make after two-sided paster PCB, plate area is no more than 12mm * 28mm, is beneficial to and embeds in gas bubble detection housing, has reduced detector space.

In order to guarantee the collection to high frequency weak signal, the utility model adopts high speed voltage comparator that the sinusoidal wave pulse of tens millivolts of peak values is switched to digital pulse signal, then processes after filtering, has improved precision and the antijamming capability of detector.The response time of hypervelocity voltage comparator is less than 10ns, the low-pass filter delay time at 2 μ s between 3 μ s, thereby the response time of integrated circuit be less than 3 μ s, for gas bubble detection provides signal response at a high speed.

Because the utility model has adopted unique signal processing method, make that ultrasonic bubble detector control circuit module volume of the present invention is small, accuracy of detection is high, fast response time, is easy to make the gas bubble detection of control circuit and sensor one.

Accompanying drawing explanation

Fig. 1 miniature ultrasonic gas bubble detection control circuit block diagram

Fig. 2 miniature ultrasonic gas bubble detection control circuit schematic diagram

Embodiment:

As shown in Figure 1, the utility model discloses a kind of miniature ultrasonic gas bubble detection control circuit, it is comprised of transmitting terminal driving, receiving end signal amplification filtering and signal mode number conversion three parts.Transmitting terminal drives and produces continuous ultrasonic pulse signal S1, for driving ultrasonic transducer transmitting ultrasound wave.In the present embodiment, supersonic oscillations frequency is 2MHz, the square wave that dutycycle is 50%.The Weak Ultrasonic ripple electric signal S2 receiving by ultrasonic transducer receiving end is admitted to signal comparator, more afterwards the rectification of ultrasound wave simulating signal is enlarged into the digital signal of Transistor-Transistor Logic level with reference signal 1S3.This signal transfers high-frequency signal the constant-direct current signal S5 of ripple below 5% to through S4 to low-pass filter again.Constant-direct current signal S5 and reference signal 2S6 carry out secondary comparison in comparer, finally obtain the digital signal output S7 of Transistor-Transistor Logic level.In the present embodiment, reference signal 1 and reference signal 2 are constant-direct current signal, and its effect is the threshold values of setting two comparers.While having liquid in gas bubble detection pipeline, ultrasonic transducer receiving end signal S2 amplitude will be higher than threshold values reference signal S3, the square-wave signal that now comparator output signal S4 is Transistor-Transistor Logic level, after filtering, direct current signal S5 will be higher than threshold values reference signal S6, so time output signal S7 be TTL high level.While having bubble or no liquid in gas bubble detection pipeline, ultrasonic transducer receiving end signal S2 amplitude will be close to 0, and now comparator output signal S4 will be TTL low level.After filtering, S5 is still TTL low level, so time output signal S7 be also TTL low level.

As shown in Figure 2, JP1 is the active crystal oscillator of a 5V to miniature ultrasonic gas bubble detection control circuit schematic diagram, and it sends excitation pulse signal as transmitting terminal drive part to ultrasonic transducer.The pin 1 of JP1 is unsettled, pin 2 ground connection, pin 3 meet power supply VCC for square-wave pulse output, pin 4.The supply voltage VCC of this circuit is 5V ± 0.5V.JP2 is the two voltage comparators of the hypervelocitys such as MAX912 or MAX9012, and its response time is in 10ns.JP2 pin 11 connects VCC power supply, and pin 3,4,6,13,14 is earth terminal, the input end that pin 7 and pin 8 are first comparer, and the ultrasonic signal receiving is connected with pin 8, and pin 7 connects reference signal 1, and reference signal 1 is by R3 and R4, R5 dividing potential drop gained.

Claims (2)

1. miniature ultrasonic gas bubble detection control circuit is driven by ultrasound wave transmitting terminal, ultrasound wave receiving end signal amplification filtering, signal mode number conversion three partial circuits form, it is characterized in that the driving of ultrasound wave transmitting terminal is provided by active crystal oscillator, ultrasound wave receiving end signal amplification filtering part is comprised of hypervelocity voltage comparator and rc low pass filter, signal digital-to-analogue conversion portion is completed by hypervelocity voltage comparator, active crystal oscillator output terminal is connected with ultrasonic transducer transmitting terminal, hypervelocity voltage comparator is comprised of comparer 1 and 2 two comparers of comparer, ultrasonic transducer receiving end is connected with comparer 1 input anode, comparer 1 output is connected with comparer 2 input anode by rc low pass filter, the input cathode of comparer 1 and comparer 2 is connected with series connection divider resistance respectively.

2. miniature ultrasonic gas bubble detection control circuit according to claim 1, is characterized in that ultrasound wave transmission frequency and ultrasound wave receive frequency are between 1MHz to 5MHz.

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