JPH0524066Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an active sonar device that detects the direction and distance of a target by emitting sound waves underwater and receiving echoes from a target object.

[Conventional technology]

Conventionally, in a sonar device that performs active reception and passive reception at the same time, when the transducer is used for both receptions, the transducer 1 is used as shown in Fig. 2.
The ground side of the matching transformer 3 and the vibration element 2
There is a method in which a diode switch 8 is provided between the ground side of the transmitter and the receiver to switch between transmission and reception. This method prevents the output level from decreasing due to the matching transformer 3 in the passively used low frequency band, and improves the receiving sensitivity.

That is, during transmission, the diode switch 8 is made conductive by the output voltage of the transmitting circuit 7, the matching transformer 3 performs a boosting action, the vibrator 2 is excited, and a sound wave is emitted. During reception, the voltage generated by the vibrator 2 is at a minute level, so the diode switch 8 is not conductive, the matching transformer 3 is connected in series, and the received signal is transmitted to the receiving circuit 6.

[Problem that the invention attempts to solve]

In the conventional sonar device described above, in the receiving state, high-level signals outside the frequency band required for active reception or passive reception, such as low-frequency high-level signals generated by the movement of the ship, are superimposed on the desired received signal. Diode switch 8
There is a drawback that the matching transformer 3 becomes conductive and the matching transformer 3 acts to reduce the pressure, causing the received signal to disappear.

[Means for solving problems]

The present invention provides an active and a passive sonar device that shares a transducer in which one end of a matching transformer is connected to one end of a vibrating element, in which one of the output terminals is connected to the other end of the vibrating element and the other is connected to the matching transformer. a transmitting circuit connected to the midpoint of the transformer; a receiving circuit having one input terminal connected to the other end of the resonating element and the other to the other end of the matching transformer; and a receiving circuit connected to the other end of the resonating element and the matching transformer. a pair of SCR switches connected in parallel in opposite directions between the other end of the matching transformer, and a desired frequency band portion of the signal applied between the other end of the vibrating element and the other end of the matching transformer; and an SCR drive circuit that generates an SCR trigger signal to make the pair of SCR switches conductive when SCR is at a required level or higher.

〔Example〕

Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 3.

In FIG. 1, during transmission, the output voltage of the transmitter circuit 7 is applied to the SCR switch 4 and the SCR drive circuit 5 through the matching transformer 3. If the input signal is in the required frequency band and the signal level is higher than the required level, the SCR drive circuit 5
An SCR drive signal is generated and the SCR switch 4 is turned on. When the SCR switch 4 is turned on, the matching transformer 3 boosts the transmission signal, excites the vibrator 2, and emits a sound wave.

During reception, the signal generated by the vibrating element 2 passes through the matching transformer 3 to the SCR switch 4,
It is added to the SCR drive circuit 5 and the reception circuit 6. Since the signal level at this time is minute, the SCR drive circuit 5 does not operate and the SCR switch 4 remains non-conductive. In addition, as shown in Fig. 3c, if a signal outside the required frequency band, for example, a high-level low frequency component caused by the movement of the ship to which the transducer 1 is fixed, is superimposed, the SCR drive circuit SCR switch 4 does not operate because it is not in the operating frequency band of 5.

3a to 3c show the input signal of the SCR drive circuit 5, the drive signal of the SCR switch 4, and the operating state of the SCR switch 4 shown in FIG.
Figure 3a shows how the SCR switch 4 operates during transmission, and Figure 3b shows how the SCR switch 4 operates when receiving.
FIG. 3c shows how the switch 4 does not perform a switching operation, and FIG. 3c shows how the SCR does not perform a switching operation even when the received signal is mixed with a high level low frequency signal outside the desired band.

[Effect of idea]

As described above, the present invention aims to improve the sensitivity of the passive frequency band by connecting the ground side of the transducer matching transformer to the connection part between the transducer, the transmitting circuit, and the receiving circuit through the SCR. This has the effect of maintaining performance even when a high-level signal mixes outside the required band.

[Brief explanation of drawings]

Figure 1 is a block diagram of one embodiment of the present invention;
The figure is a block diagram of a conventional sonar device, Figure 3a.
-c are diagrams showing the operation of the embodiment shown in FIG. 1. 1... Transducer/receiver, 2... Vibration element, 3... Matching transformer, 4... SCR switch, 5...
SCR drive circuit, 6...reception circuit, 7...transmission circuit, 8...diode switch.

Claims (1)

[Scope of utility model registration request] In an active and passive sonar device that shares a transducer in which one end of a matching transformer is connected to one end of a vibrating element, one of the output terminals is connected to the other end of the vibrating element, and the other is connected to the midpoint of the matching transformer. a receiving circuit having one input terminal connected to the other end of the vibrating element and the other to the other end of the matching transformer; a pair of SCR switches connected in parallel in opposite directions between the ends of the vibration element and the other end of the matching transformer, and a portion of the required frequency band of the signal applied between the other end of the vibrating element and the other end of the matching transformer is equal to or higher than the required level. Generates an SCR trigger signal when the pair of SCRs
A sonar device comprising: an SCR drive circuit that conducts a switch.