JPS5826281A - Receiver for shipwreck prevention - Google Patents

Abstract

PURPOSE:To shorten a search activity time greatly by providing a receiving antenna with sharp directivity in a swiveling state, and detecting a direction where a radio transmitter held by a crewman is present. CONSTITUTION:A receiving antenna 13 having sharp directivity is rotated by a driving device 26, and an antanna angle detection part 27 and an antenna angle display part 28 are provided to display a high directivity direction of the antenna 13. At the same time, an FM-modulated electromagnetic wave received by the antenna 13 is amplified by a high frequency tuned amplifier circuit 14, whose output is mixed with a local oscillation signal generated by a local oscillating circuit 15 by a mixing circuit to obtain an intermediate frequency signal. This signal is amplified by an intermediate frequency amplifier circuit 17, whose output is displayed on an electromagnetic wave intensity display part 28 together with an antenna angle; when the output of the circuit 17 is maximum, the presence of a transmitter is known from the antenna angle.

Description

[Detailed Description of the Invention] The present invention, when a crew member or a passenger of a ship or the like falls into water or seawater (hereinafter referred to as seawater), the position of the person who has fallen is known, the rescue operation can be shortened, and the person who has fallen can be saved. The purpose of this invention is to provide a receiving device for preventing marine accidents that can protect lives.

As we all know, once a ship sets sail, it is in motion day and night until it re-arrives at a port.If a ship's crew or passengers unexpectedly fall from the ship into seawater, it may be difficult to find the ship due to the delay in discovery. may lead to fatal accidents. In addition, they must work at night in extremely dangerous conditions, such as waiting in the wind, and it is highly conceivable that other crew members or passengers may not notice if they fall. If you realize that you have fallen after some time has passed, it means that the ship has progressed that much, and even if you start a search immediately, the search area is wide and the search will often be difficult.

Therefore, as a conventional means of preventing marine accidents of this kind, crew members wear life vests coated with fluorescent paint, and if a person falls into seawater, they can be detected visually. However, in winter at sea or during storms, the waves are high, and the longer the distance between the person who fell and the ship, the more difficult it is to find them. Therefore, there is a long-awaited desire among shipworkers for a device to accurately and quickly notify other crew members if a crew member falls from a ship. .

In view of the above-mentioned points, the present invention provides crew members or
If a passenger falls into seawater, a radio transmitter carried by the crew member or passenger to prevent marine accidents will emit electromagnetic waves, which will be received by a radio receiving device installed inside the ship. The purpose is to provide a receiving device for marine accident prevention that can know the direction in which the transmitter is located.
The present invention will be explained below with reference to FIGS. 1 and 2.

FIG. 1 shows a transmitter, and in the event of an accidental fall from a ship or the like into seawater, the water landing detection unit 10 detects the fall. Upon detection, the switch unit 11 closes and the power supply unit 9 Power is supplied to each part.

When power is supplied, the low frequency signal circuits 2 and 3 generate low frequency signals f1 (50K) (about z) and f2 (about IKHz), and the AM modulation circuit 4 performs low frequency modulation. High frequency signal f generated by high frequency signal generation circuit 1
3 (approximately 75 MHz) and performs FM modulation in the fM modulation circuit 6, and then passes through the two-stage amplifier 1] circuits 6 and 7 to the antenna 8.
It emits more FM modulated electromagnetic waves.

As shown in FIG. 2, in the single power receiving device, the electromagnetic waves received by the antenna 13 are tuned and amplified by the transmitter carrier frequency in the high frequency tuning amplification circuit 14, and the local oscillation generated in the local oscillation circuit 16 is mixed. The circuit 16 mixes the intermediate frequency (10, 7
MHz). The intermediate frequency amplification circuit 17 amplifies the intermediate frequency of the modulated signal, the FM detection circuit 18 takes out the low frequency modulation signal, the amplification circuit 19 amplifies it, and only the low frequency signal f1 is passed. It passes through the filter circuit 2o, and then, if it is a low frequency signal f2, it is guided to the filter circuit 21 which generates a voltage. If I send a signal, will it continue to send until the power supply voltage drops and it stops sending? ing. Therefore, the present invention is designed to connect the receiving antenna 13 with sharp directivity to the driving device 2.
6, and an antenna angle detection section 27 and an antenna angle display section 28 are provided to display the direction of the sharp directivity of the antenna 13. At the same time, the FM modulated electromagnetic waves received by the antenna 13 are transmitted to the high frequency tuning amplification circuit 14. Tuning is amplified, the local oscillation generated by the local oscillation circuit 16 is mixed by a mixing circuit, converted to an intermediate frequency (10.7 MHz), amplified by an intermediate frequency amplification circuit 17, and the output is displayed as an electromagnetic wave intensity display. This is displayed together with the antenna angle in section 28 so that the direction of transmission of the FM modulated electromagnetic waves can be confirmed.

That is, by reading the antenna angle when the output of the amplifier circuit 17 is maximum, it is possible to know the direction in which the transmitter is present.

As described above, according to the present invention, since the direction in which electromagnetic waves are transmitted can be known, the search time can be greatly shortened, which is effective in protecting the lives of people who have fallen. This is particularly useful for searching at night and in dense fog.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a transmitter used in a marine accident prevention receiving apparatus according to the present invention, and FIG. 2 is a block diagram of a marine accident prevention receiving apparatus according to an embodiment of the present invention. 13...Receiving antenna, 14.'. ... High frequency 1 tuning amplification circuit, 16 ... Local oscillation circuit,
16...Mixing circuit, 17...Intermediate amplification circuit, 26...Antenna drive device, 27...
...Antenna angle detection circuit, 28...Antenna angle, electromagnetic wave intensity display section.

Claims (1)

[Claims] A signal transmitted from a radio transmitter carried by a crew member of a ship, etc. is received by a receiving antenna with sharp directivity, and this receiving antenna is configured to be able to turn, and the maximum point of the signal received by the receiving antenna is A receiving device for marine accident prevention characterized by detecting the direction in which a wireless transmitter is present based on the direction of a receiving antenna.