JPS6151744B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sounding device (also called a fishfinder or Dave's sounder). More specifically, it relates to a device that uses ultrasonic waves to determine the state of seawater (or underwater), the state of the seabed, the depth, etc.

One type of conventional device of this type is known as a flash type device which uses a rotary plate equipped with light emitting elements to indicate an indication by blinking the light emitting elements with respect to a rotor having a depth indicating scale.

The flasher type device has a motor with a rotor equipped with a light emitting device (LED) which is energized in a rotating transformer manner. This motor is equipped with a circuit that generates one revolution pulse. This one-rotation pulse determines the timing of the ultrasonic sounding pulse.
The time difference between the reflected or echo pulses causes the LED to shift in rotational position and blink. The blinking rotational position deviation of this LED is made to correspond to the depth indication.

Conventional devices of this type are usually provided with a time constant circuit so that an alarm can be issued when the time difference between echo pulses is within a preset value. This time constant circuit is a window whose length can be set arbitrarily from the timing of one rotation pulse.
Generates a pulse. If the timing of occurrence of an echo pulse occurs within this wind pulse, an alarm signal is generated to avoid, for example, running a boat into shallow water. It is also possible to specify when an echo pulse exceeding the width of the wind pulse occurs, that is, at a depth greater than a predetermined value (which can be set in advance).

The present invention combines another time constant circuit to provide both ends of the sounding range of the sounding device (i.e., one
The time difference between the rotational pulse and the echo pulse is 0 and the maximum time difference between the echo pulse associated with one rotational pulse and the position of the next rotational pulse is 2.
The purpose of this invention is to form two wind pulses and to make the width of these pulses adjustable, thereby making it possible to specify a predetermined depth width. The second time constant circuit is adjustable in its wind pulse width from 0 to a point where it can overlap with the window pulse width of the second time constant circuit, and when set to that 0 time width, the conventional device functions. The same function is performed. By setting the width of the wind pulse of the first time constant circuit to 0 in advance, the wind pulse given by the second time constant circuit now produces an echo pulse in the presettable pulse. An alarm indication can be given when a preset depth is exceeded, or vice versa, it is also possible to give an alarm indication up to a preset depth.

FIG. 1 shows a block diagram of one embodiment of the present invention.
The motor 10 is connected to an LED flasher circuit 12 and a one-rotation pulse generation circuit 14. Motor 1
0 can select two speeds by a speed control circuit (not shown). This speed switching means is represented by a switch 15 shown in conjunction with the one revolution pulse generator 14. This switch 15, which is normally shown as OFF, causes the motor to rotate at a low speed in a first, OFF position, and at a high speed in a second, ON position.

The single revolution pulse generator 14 is a conventional circuit capable of generating one pulse per revolution of the motor. This pulse is transmitted by the transmitting/receiving pulse conversion circuit 1
6 to provide the timing of transmitting ultrasonic pulses from an ultrasonic transducer (not shown). The transmitted ultrasonic pulse (echo pulse) is converted into an electrical pulse with the same timing by a pulse conversion circuit 16, and is provided to a first time constant circuit 18.

The first time constant circuit 18 receives pulses from the one-rotation pulse generation circuit 14 indicating the timing of the transmitted ultrasonic pulses and pulses from the pulse conversion circuit 16 indicating the timing of the received ultrasonic pulses. The time difference between these pulses indicates the measured depth. 1st
A time constant circuit 18 generates a first window pulse resulting from the timing of the transmitted ultrasound pulse. The width of this wind pulse is adjustable by setting means 2.
It can be freely set to 0.

Figure 2A shows the output pulse from the circuit 14 (T pulse) showing one revolution pulse of the motor, that is, the transmitted ultrasonic pulse, and Figure 2B shows the output pulse from the circuit 16 (R pulse) showing the echo pulse in some cases. shows. The R pulse 26 represents the reception timing of the echo pulse of the ultrasonic transmission pulse generated at the timing of the T pulse 22. T-pulse 24 represents the timing of the next transmitted pulse.

FIG. 2C shows the second window pulse 28 formed by the first time constant circuit 18. The first window pulse 28 extends from the timing of each T pulse, the timing t ₁ of its termination being set by the adjustable setting means 2
given by 0.

According to the invention, a second time constant circuit 30 is provided. A second time constant circuit 30 provides a wind pulse 32 shown in FIG. 2C. The wind pulse 32 begins with a timing t ₂ provided by the adjustable setting means 34 and extends until the next one revolution pulse 24 . An alarm drive circuit 36 such as a buzzer is connected to the second time constant circuit 30 .

A gate circuit 38 is provided connected to the first and second time constant circuits. The gate circuit 38 operates when the R pulse of FIG. 2B is between the first and second window pulses 28, 32 (i.e., the state of FIG. 2B).
The pulse 26 is applied to the LED flasher circuit 12. The flasher circuit 12 includes an oscillator with a frequency sufficiently higher than the rotational frequency of the motor 10 (for example, 58 KHz). Usually, a light emitting element such as an LED is attached to the circumference of a rotary plate coaxially provided with the rotor of the motor 10, and this is energized by a rotary transformer or a commutator. The pulse 26 from the gate circuit 38 described above is waveform-shaped by the LED flasher circuit 12, drives an oscillation circuit, is converted into a burst of oscillation frequency at that timing, and energizes the LED via a rotary transformer. Since the LED is synchronized with the rotation of the motor, the circular position corresponding to one rotation of the motor (Fig. 2A)
The interval between the one-turn pulses 22 and 24 corresponds to a gauge of 360°. ) blinks at a position corresponding to the circular deviation of the pulse 26. This circle gauge is graduated according to depth, allowing direct reading of the energized position of the LED.

As mentioned above, motor 10 is capable of two speeds. That is, the depth sounding device of this embodiment can perform depth sounding in two types of depth units.
The second motor speed relative to the first motor speed changes the pulse spacing in FIG. 2A. accordingly the first
The time constants of the second time constant circuits are also changed by the switches 19 and 31. Each switch changes the width of the wind pulse in proportion to the change in the period of the one revolution pulse (FIG. 2A).

FIG. 3 shows the first and second time constant circuits 18, 30.
and a more detailed circuit configuration of the gate circuit 38. The time constant circuits 18 and 30 are composed of a well-known IC, 74C221, which has two monostable multi circuits (Figure 3A shows its internal circuit and logic table), and the circuit 38 is composed of four two-input OR gates. It is composed of a well-known IC, TC4071P (Figure 3B shows its internal configuration). The input 40 receives one rotation pulse (T pulse) of the motor 10 from the circuit 14.
A pulse (R pulse) indicating the timing of the echo pulse is supplied from the circuit 16 to the input 42. A line 44 is connected to the LED flasher circuit 12 as an output of the gate circuit 38, and a line 46 is connected to the buzzer drive circuit 36. Alarm mode switch 48 has an alarm on position 48a and an alarm set position 48b, with the alarm mode switch 48 having an alarm on position 48a and an alarm set position 48b.
Allows setting of t ₁ and t ₂ .

[Brief explanation of the drawing]

Figure 1 is a schematic circuit diagram of an embodiment of the present invention, Figure 2 is a waveform diagram showing its operation, Figure 3 is a detailed circuit diagram of a portion of Figure 1, and Figures 3A and B are used in Figure 3. A block diagram of the circuit is shown. In the figure, 18 is a first time constant circuit, 30 is a second time constant circuit, and 38 is a gate circuit.

Claims (1)

[Claims] 1 means for generating a one-rotation pulse of a motor; means for emitting an ultrasonic pulse in response to the one-rotation pulse and converting a received ultrasonic echo pulse into an electrical echo pulse; and a means for receiving the electrical echo pulse; A sounding device that indicates the timing difference of this electrical echo pulse with respect to the one-rotation pulse corresponding to the ultrasonic transmission pulse as a depth measurement value by energizing a light emitting element rotating in synchronization with the motor at the timing of the electrical echo pulse. In 1 above,
a first time constant circuit that generates a first window pulse having a pulse width from the timing of generation of the one-rotation pulse to a first timing that is tunably set according to the rotation pulse; and a second time constant circuit for generating a second window pulse having a pulse width from the second timing set to the timing at which the next one-rotation pulse occurs, and the electrical echo pulse is 1. A sounding device characterized in that a gate circuit is configured to detect the absence of the first and second wind pulses between two adjacent one-rotation pulses.