JP2002210408A - Device for driving ultrasonic vibrator transducer and underwater detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to be compatible with ultrasonic vibrator transducers of various specifications without providing a transformer with intermediate taps. SOLUTION: Voltages V1, V2 to be applied across both ends of respective ultrasonic vibrator transducers 12, 16 are controlled by controlling a pulse width of a pulse outputted to the primary side of a transformer 7 from a transmission circuit 1. Since the voltages across the transducers are decreased when the pulse width is narrow, while the voltages across the transducers are increased when the pulse width is wide, the transducers 12, 16 are applied with the voltages according to the pulse widths, and the driving device is compatible with the ultrasonic vibrator transducers of various specifications by using only a single transmission circuit and a transformer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving apparatus for an ultrasonic transducer used for a two-frequency fish finder, for example.
The invention also relates to an underwater detection device such as a fish finder or a sounding device.

[0002]

2. Description of the Related Art A two-frequency fish finder is a fish finder equipped with two ultrasonic transducers for transmitting and receiving high-frequency (for example, 200 KHz) and low-frequency (for example, 50 KHz) ultrasonic signals. The high frequency and the low frequency are used properly according to the purpose. High-frequency ultrasonic signals have high resolution and sharp beam directivity, and thus are suitable for detecting small areas in water. On the other hand, a low-frequency ultrasonic signal has a low resolution, but has a wide beam directivity, and thus is suitable for detecting a wide area in water.

Conventionally, a device for driving two ultrasonic transducers in such a two-frequency fish finder is shown in FIG. In the figure, reference numeral 21 denotes a transmission circuit that outputs a pulse of a frequency f1 (high frequency), reference numeral 22 denotes a transformer to which a pulse output from the transmission circuit 21 is applied to the primary side, reference numeral 23 denotes a transformer connected to the secondary side of the transformer 22, and An ultrasonic transducer that generates an ultrasonic signal of f1. 24 is a transmission circuit that outputs a pulse of frequency f2 (low frequency), 25 is a transformer to which the pulse output from the transmission circuit 24 is applied to the primary side, 26 is connected to the secondary side of the transformer 25,
This is an ultrasonic transducer that generates an ultrasonic signal having a frequency f2. However, this device requires two transmitting circuits 21 and 24 for high frequency and low frequency, and these are separate circuits, so there is a disadvantage that the cost is high.

Therefore, a device shown in FIG. 11 has been known as a device capable of coping with both a high frequency and a low frequency with one transmission circuit. In FIG. 11, reference numeral 30 denotes a transmission circuit that alternately outputs pulses of frequency f1 (high frequency) and frequency f2 (low frequency), 31 denotes a transformer to which the pulse output from the transmission circuit 30 is applied to the primary side, and 32 denotes a transformer. A resonance circuit connected to the secondary side of the transformer 31 and resonating at the frequency f1; 33, an ultrasonic transducer connected in series with the resonance circuit 32; 34, a connection to an intermediate tap 36 on the secondary side of the transformer 31; A resonance circuit which resonates at the frequency f2, and an ultrasonic transducer 35 connected in series with the resonance circuit 34.

In the apparatus shown in FIG. 11, the transmitting circuit 30 alternately outputs pulses of frequency f1 and frequency f2,
When a pulse of 1 is output, the resonance circuit 32 resonates and a voltage of Vα is applied to both ends of the ultrasonic vibrator 33. Based on this voltage, the ultrasonic vibrator 33 generates an ultrasonic signal of frequency f1. appear. When the pulse of the frequency f2 is output, the resonance circuit 34 resonates and the ultrasonic vibrator 35
Is applied to both ends of the ultrasonic transducer 35, and the ultrasonic transducer 35 generates an ultrasonic signal of the frequency f2 based on this voltage.
According to this device, since only one transmitting circuit 30 and one transformer 31 are required, the circuit configuration is simplified as compared with the case of FIG.

[0006]

However, the voltage applied to both ends of the ultrasonic transducer differs according to the frequency of the transducer and the transmission output. For example, 1 for frequency
If there are several types between 5 KHz and 400 KHz, and there are several tens of transmission outputs between 300 W and 10 KW, the number of this combination is considerably large. For this reason, in the apparatus shown in FIG. 11, if one type of transformer 31 is used for all types of transducers, FIG.
As described above, it is necessary to provide a large number of intermediate taps 40 on the secondary side of the transformer 31 to make the voltage applied to the ultrasonic transducer variable. However, this has a problem that the number of the intermediate taps 40 is unnecessarily increased, which complicates the structure of the transformer 31 and increases its size.

The present invention has been made to solve the above-mentioned problems, and is to make it possible to cope with ultrasonic transducers of various specifications without providing an intermediate tap in a transformer even when one transmission circuit and a transformer are used. It is an issue.

[0008]

To solve the above problems, the present invention controls the voltage applied to both ends of an ultrasonic transducer by controlling the pulse width of a pulse output from a transmission circuit. It is intended to be. By doing so, the voltage applied to both ends of the ultrasonic transducer can be adjusted according to the pulse width, so that it is not necessary to provide a large number of intermediate taps in the transformer in order to adjust the voltage. The structure is simplified, and the circuit can be made small and lightweight.

In a typical embodiment of the present invention, a transmitting circuit includes a pulse generating circuit and a control unit for controlling a frequency and a pulse width of a pulse generated by the pulse generating circuit. In this case, an input unit for inputting information (for example, a model) for designating an ultrasonic transducer to be connected is provided,
The control unit can be configured to control the frequency and pulse width of the pulse based on the information input from the input unit.

In order to prevent a voltage from being simultaneously applied to a plurality of ultrasonic transducers for a pulse output from the transmission circuit, a resonance circuit which resonates in accordance with the frequency of the pulse is provided. In a typical embodiment, a resonance circuit is connected in series to each ultrasonic transducer, and a plurality of series bodies including the resonance circuit and the ultrasonic transducer are connected in parallel to the secondary side of the transformer.

[0011]

FIG. 1 is a block diagram showing an example of a two-frequency fish finder according to an embodiment of the present invention. Here, only blocks related to the present invention are shown, and a display unit and the like are not shown. In FIG.
Reference numeral 1 denotes a transmission circuit that outputs pulses of a plurality of types (here, two types) of frequency, a pulse generation circuit 2, a CPU
3, a memory 4, a switching circuit 5, and a high-voltage power supply circuit 6. 7 is a transformer to which a pulse output from the transmission circuit 1 is applied to the primary side, 7a is a primary winding of the transformer 7, 7b is a secondary winding of the transformer 7, and 8 is C
An input unit for inputting various commands and data to the PU 3. The transmission circuit 1, the transformer 7, and the input unit 8 constitute a driving device for the ultrasonic transducer.

Both ends of the secondary winding 7b of the transformer 7 have L
A series body of a C resonance circuit 11 and an ultrasonic transducer 12;
A series body of the C resonance circuit 15 and the ultrasonic vibrator 16 is connected in parallel. The LC resonance circuit 11 includes a coil 9 and a capacitor 10 connected in series, and has a resonance frequency set to f1. The LC resonance circuit 15 includes a coil 13 and a capacitor 14 connected in series, and has a resonance frequency set to f2. One end of the secondary winding 7b of the transformer 7 is connected to a receiving circuit (not shown).

Next, the operation of the apparatus shown in FIG. 1 will be described. In the transmission circuit 1, based on a transmission command from the CPU 3, the pulse generation circuit 2, as shown in FIG.
A (high-frequency) pulse P1 and a frequency f2 (low-frequency) pulse P2 are generated alternately. The CPU 3 constitutes the control unit of the present invention, and the pulse P generated by the pulse generation circuit 2
1, the pulse width of P2 is controlled. As will be described later, by controlling the pulse width, the ultrasonic transducers 12 and
It is possible to control the voltages V1 and V2 applied to both ends of the 16.

Prior to performing the pulse width control as described above, information for designating the ultrasonic transducers 12 and 16, for example, the type of the transducers, is input to the input unit 8 and set in the memory 4. Keep it. The CPU 3 reads out the frequency and the transmission output corresponding to the transducer of the corresponding type stored in the memory 4 in advance based on the set information, and sends the frequency and the pulse to the pulse generation circuit 2 based on these. Outputs a control signal specifying the width.
The input unit 8 may directly input a frequency or a transmission output corresponding to the vibrator instead of the model.

In response to the control signal, the pulse generation circuit 2
From this, pulses P1 and P2 having a predetermined frequency and a predetermined pulse width shown in FIG. 2 are output, and these pulses are input to the switching circuit 5. The switching circuit 5 comprises a well-known push-pull power amplifying circuit having two power transistors, and switches the power supply voltage Vo of the high-voltage power supply circuit 6 by turning on / off the transistor based on the pulse. Are output to the primary winding 7a of the transformer 7 as shown in FIG. At this time, the voltage V (amplitude value) of each pulse is V
= 2Vo. FIG. 3A shows a pulse P1 having a frequency f1.
3 shows a pulse 51 generated based on FIG.
(B) shows the pulse 52 generated based on the pulse P2 of the frequency f2. The value of the voltage V can be adjusted by configuring the high-voltage power supply circuit 6 with a variable power supply.

Now, the primary winding 7a of the transformer 7 is
When the pulse 51 (frequency f1) of (a) is output,
The voltage generated across the secondary winding 7b of the transformer 7 based on the pulse 51 causes the resonance circuit 11 to resonate,
A voltage V1 (amplitude value) is applied to both ends of the ultrasonic transducer 12. The waveform of this voltage is a sine wave. Ultrasonic transducer 1
2 generates an ultrasonic signal having a frequency f1 by applying the voltage V1. Also, the primary winding 7a of the transformer 7 is
When the pulse 52 (frequency f2) of (b) is output,
The voltage generated on the secondary side of the transformer 7 based on the pulse 52 causes the resonance circuit 15 to resonate, and a voltage V2 (amplitude value) is applied to both ends of the ultrasonic transducer 16. The waveform of this voltage is also a sine wave. The ultrasonic transducer 16 has a voltage V
2 generates an ultrasonic signal of frequency f2.

In this way, the frequency f
The pulse 51 of frequency 1 and the pulse 52 of frequency f2 are alternately output, and the ultrasonic transducers 12 and 16 are alternately driven, so that the ultrasonic transducers 12 and 16 output the frequency as shown in FIG. The ultrasonic signal 61 of f1 and the ultrasonic signal 62 of frequency f2 are transmitted alternately.

Here, the resonance circuit 15 does not resonate with the pulse 51 of the frequency f1, so that the voltage V2 across the ultrasonic vibrator 16 becomes almost zero, and the vibrator 16 does not operate. Further, the resonance circuit 11 does not resonate with the pulse 52 having the frequency f2.
The voltage V1 across the two terminals 2 is almost zero, and the vibrator 12 does not operate. Thus, the ultrasonic vibrator 1 is controlled by the resonance circuits 11 and 15 having the resonance frequencies corresponding to the respective frequencies.
2 and 16 can be selectively driven, and isolation between the two vibrators is ensured.

As described above, since there are many types of frequency and transmission output specifications in the ultrasonic vibrator, it is necessary to change the voltage applied to the vibrator according to the ultrasonic vibrator to be used. is there. Therefore, in the present invention, by controlling the pulse widths W1 and W2 of the pulses 51 and 52 in FIG. 3, the voltages V1 and V2 across the ultrasonic transducers 12 and 16 are adjusted, and the ultrasonic waves generated from the transducers are adjusted. The transmission output of the signal is controlled.

FIG. 5 is a diagram showing the relationship between the pulse width and the voltage applied to the vibrator. As shown in FIG.
When the pulse width of the pulse No. 1 is W1a, a voltage having an amplitude value V1a as shown by a solid line in FIG. When the pulse width is changed from W1a to W1b (W1a <W1b), a voltage having an amplitude value V1b as shown by a broken line in FIG. 5B is applied to both ends of the ultrasonic transducer 12 (V1a <V1b). ). That is, if the pulse width of the pulse 51 is reduced, the voltage at both ends of the ultrasonic transducer 12 decreases, and if the pulse width of the pulse 51 is increased, the voltage at both ends of the ultrasonic transducer 12 increases. Therefore, FIG.
As shown in FIG. 7 and FIG. 7, by changing the duty of the pulse 51 and controlling the pulse width, the voltage applied to the ultrasonic transducer 12 can be changed as V1a and V1b.
As a result, one transmission circuit 1 and one transformer 7 can support transducers of various specifications. The same applies to the pulse width W2 of the pulse voltage 52 and the voltage across the ultrasonic vibrator 16.

FIGS. 8 and 9 show ultrasonic signals output from the ultrasonic transducers 12 and 16 when the above-described pulse width control is performed. FIG. 8 shows an example in which the pulse width W1 of the pulse 51 is wider than the pulse width W2 of the pulse 52. The amplitude of the ultrasonic signal 61 (frequency f1) emitted from the ultrasonic transducer 12 is Ultrasonic signal 62 (frequency f2) emitted from vibrator 16
, And the high-frequency transmission output increases. FIG. 9 shows the pulse width W of the pulse 52, which is opposite to FIG.
This is an example in which 2 is wider than the pulse width W1 of the pulse 51, and the ultrasonic signal 6 emitted from the ultrasonic transducer 16
2 is larger than the amplitude of the ultrasonic signal 61 emitted from the ultrasonic transducer 12, and the transmission output of the low frequency is increasing.

In the above embodiment, the high-frequency pulse and the low-frequency pulse are alternately output from the pulse generation circuit 2. In addition, the high-frequency pulse or the low-frequency pulse is output from the pulse generation circuit 2. A function of continuously outputting only the frequency pulse may be added. in this case,
Alternately output high and low frequency pulses,
Whether to continuously output only the high-frequency pulse or the low-frequency pulse may be selected by a changeover switch or a screen operation in the input unit 8.

In the above description, an example using two frequencies is shown, but the present invention can be applied to a case where three or more frequencies are used. In the above description, a fish finder was used as an example of the underwater detection device. However, the present invention can also be applied to a sounder or a sonar for measuring the distance to the bottom of the water.

[0024]

As described above, according to the present invention, since the applied voltage of the ultrasonic vibrator is controlled by controlling the pulse width, it is not necessary to provide a large number of intermediate taps in the transformer. The structure of the transformer is simplified, and the circuit can be made small and lightweight. In addition, since one transmission circuit can cope with the specifications of an ultrasonic transducer having various frequencies and transmission outputs, the versatility of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a two-frequency fish finder according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating pulses output from a pulse generation circuit.

FIG. 3 is a diagram illustrating pulses output to the primary side of a transformer.

FIG. 4 is a diagram showing an ultrasonic signal transmitted from an ultrasonic transducer.

FIG. 5 is a diagram showing a relationship between a pulse width and a voltage applied to a vibrator.

FIG. 6 is a diagram showing an applied voltage of a vibrator when a pulse width is narrow.

FIG. 7 is a diagram showing an applied voltage of a vibrator when a pulse width is wide.

FIG. 8 is a diagram showing an ultrasonic signal when pulse width control is performed.

FIG. 9 is a diagram illustrating an ultrasonic signal when pulse width control is performed.

FIG. 10 is a diagram showing a conventional example.

FIG. 11 is a diagram showing another conventional example.

FIG. 12 is a diagram illustrating an intermediate tap in another conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission circuit 2 pulse generation circuit 3 CPU (control unit) 4 memory 5 switching circuit 6 high-voltage power supply circuit 7 transformer 8 input unit 11, 15 resonance circuit 12, 16 ultrasonic transducer 51, 52 pulse 61, 62 ultrasonic signal W1 , W2, W1a, W1b Pulse width V1, V2, V1a, V1b Applied voltage of oscillator

Continued on the front page F term (reference) 5D107 AA06 AA12 AA13 BB09 CD02 CD03 DE02 5J083 AA02 AB01 AB08 AC32 AE04 AE06 BA05 BA09 CB13 CC01 CC05

Claims (5)

[Claims] A transmission circuit for outputting pulses of a plurality of types of frequencies; and a transformer to which a pulse output from the transmission circuit is applied to a primary side. In the ultrasonic vibrator driving device for selectively driving a plurality of ultrasonic vibrators connected to the next side, by controlling the pulse width of the pulse, both ends of the ultrasonic vibrator driven by the pulse A driving device for an ultrasonic vibrator, which controls a voltage applied to the ultrasonic transducer. 2. The ultrasonic transducer driving device according to claim 1, wherein the transmission circuit includes a pulse generation circuit and a control unit that controls a frequency and a pulse width of a pulse generated by the pulse generation circuit. A driving device for an ultrasonic vibrator, comprising: 3. The ultrasonic vibrator driving apparatus according to claim 2, further comprising: an input unit for inputting information for designating an ultrasonic vibrator connected to a secondary side of a transformer, wherein the control unit includes: Is a device for controlling the frequency and pulse width of a pulse based on information input from the input unit. 4. A transmission circuit for outputting pulses of a plurality of kinds of frequencies; a transformer to which a pulse generated by the transmission circuit is applied to a primary side; A plurality of ultrasonic transducers selectively driven in accordance with a frequency; controlling a pulse width of the pulse to control a voltage applied to both ends of the ultrasonic transducer driven by the pulse; Underwater detection device characterized by performing. 5. The underwater detection device according to claim 4, wherein a resonance circuit that resonates in accordance with a frequency of the pulse is connected in series to each of the ultrasonic vibrators. Wherein a plurality of series bodies are connected in parallel to the secondary side of the transformer.