JPH0748915B2 - Leakage prevention device for underwater speaker - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for an underwater speaker in which a speaker circuit is housed in a hermetically sealed container, and is capable of preventing leakage of electric current when there is water in the hermetically sealed container. Regarding

[0002]

2. Description of the Related Art Conventionally, as an underwater speaker, a waterproof sealed container, a speaker circuit housed in the sealed container, and driven by this speaker circuit,
Some have a mechanical vibration device that outputs sound into the water.

[0003]

By the way, in the above-mentioned conventional underwater speaker, when water leaks into the closed container, the speaker circuit leaks electricity to the closed container or a conductive member in the closed container, There is a problem that the speaker circuit and the like are damaged and people underwater receive an electric shock.

Therefore, an object of the present invention is to prevent leakage of an underwater speaker capable of cutting off a drive signal to the speaker circuit by detecting a leakage current by a sensor in the closed container when water is leaked into the closed container. To provide a device.

[0005]

In order to achieve the above object, an underwater speaker leakage prevention device of the present invention is connected to a closed container having a speaker circuit inside, a bias voltage source, and the speaker circuit. , Two signal lines to which a voltage is applied from the bias voltage source, a sensor provided close to the speaker circuit in the closed container, and a current flowing through water between the speaker circuit and the sensor. And a circuit breaker that receives the leakage detection signal from the detection circuit and cuts off the input of the drive signal to the speaker circuit.

Further, the detection circuit and the interruption device may be arranged in the closed container.

Further, it is desirable to provide a reporting device which receives the leakage detection signal of the detection circuit and notifies the leakage by at least one of display and sound.

[0008]

According to the leakage preventive device for an underwater speaker having the above structure, when water leaks into the sealed container, the speaker circuit and the sensor to which a voltage is applied from the bias voltage source through the two signal lines are connected. An electric current flows through the water, and the electric current is detected by the detection circuit. The interruption device, which receives the leakage detection signal of the detection circuit, cuts off the input of the drive signal to the speaker circuit. Therefore, electric leakage is prevented.

Since the bias voltage source is different from the driving power source for the speaker circuit, it can be set to a low voltage, and only a minute current flows through the sensor when a leakage is detected, which does not actually affect people in water. .

Further, in the normal state, since no current flows from the bias voltage source, the sound is not affected and there is no energy loss.

Further, when the above-mentioned notification device is provided, the above-mentioned notification device receives the leakage detection signal of the detection circuit and informs the person of the leakage by at least one of the display and the sound.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a detailed description of the leakage preventive device for an underwater speaker according to the present invention.

FIG. 1 shows a circuit diagram of a leakage preventive device for an underwater speaker according to an embodiment of the present invention. Reference numeral 1 denotes a hermetic container placed in water 10. The dynamic vibration device SP and the sensor 6 are housed. S is a detection circuit that receives a signal from the sensor 6 to detect electric leakage, C is a cutoff device that cuts the input of the drive signal to the speaker circuit 5 when the detection circuit S detects electric leakage, and W is the above It is a notification device that receives a signal from the detection circuit S and notifies the electric leakage.

The speaker circuit 5 includes signal lines L1 and L2.
Is connected to a transformer T, and the audio signal from the signal source SG is amplified by the amplifier AMP1 and input to the transformer T. That is, the audio signal from the signal source SG is input to the speaker circuit 5 via the amplifier AMP1, the output transformer T, and the signal lines L1 and L2. In addition, the signal lines L1,
Bias voltage source Vcc is applied to L2 via resistors R9 and R10.
To apply a voltage Vcc. Then, the speaker circuit 5 outputs sound into the water through the mechanical vibration device SP. A sensor is attached so as to be close to the speaker circuit 5 in the closed container 1. And the sensor 6
Is connected outside the closed container 1 through the sensor signal line L3 and the ground E to the resistors R1 and R2 of the detection circuit S, and between the sensor 6 and the chassis ground 20. Capacitor C for removing the inductive signal from
1 is connected.

In a state where water does not enter the closed container 1, the speaker circuit 5 and the sensor 6 in the closed container 1 are insulated from each other, so that the resistors R1 and R2 of the detection circuit S are connected to each other. No current flows, the transistor Q1 whose base is connected to the connection point between the resistors R1 and R2 is turned off, and the transistor Q1 passes through the resistor R3 and the diode D1.
A current flows from the power supply Vcc to the base of No. 2, and the transistor Q2 is turned on. Therefore, current flows through the transistor Q2 through the resistor R4 connected between the power supply Vcc and the collector of the transistor Q2, and the collector of the transistor Q2 becomes L level. Therefore,
Since the base of the transistor Q3, which is connected to the collector of the transistor Q2 via the resistor R5, becomes L level, the transistor Q3 is turned off. The collector of the transistor Q3 is connected to the power source Vcc via the resistor R6.
Connected to. Therefore, the output of the detection circuit S appearing at the connection point X between the collector of the transistor Q3 and the resistor R6 is at the H level because the transistor Q3 is off when water does not enter the closed container 1. .

The capacitor C2 connected between the base and collector of the transistor Q1 suppresses the high frequency operation of the transistor Q1. Further, a capacitor C3 for off-delay of the transistor Q2 is provided between the base of the transistor Q2 and the ground E.
And the diode D2 are connected in parallel.

On the other hand, a flip-flop FF is formed by the NAND circuits Q5 and Q6, and the output of the detection circuit S is held by this flip-flop FF. A resistor R7 is connected between the power supply Vcc and one input of the NAND circuit Q6.
A capacitor C4 is connected between the input of 6 and the ground E. When the power supply Vcc is turned on at the start of operation of the detection circuit S, the input of the NOT circuit Q6 is at the L level for a while while the capacitor C4 is charged, and the input of the NOT circuit Q5 is the resistor R6. Since it is connected to the power supply Vcc via the HV level, the output of the NAND circuit Q5 side is reset to the L level and the output of the NOT circuit Q6 is reset to the H level.

The output of the NOT circuit Q5,
That is, the output Y of the flip-flop FF is connected to the base of the transistor Q4 via the resistor R8 of the breaking device C. Since the output Y of the flip-flop FF is L level, the transistor Q4 is turned off. The power source V
Relay RL between cc and collector of transistor Q4
The coil No. 1 and the diode D3 for absorbing back electromotive force are connected in parallel. Since the transistor Q4 is off, no current flows through the coil of the relay RL1 and the relay RL1
The switching circuit of No. 1 connects the signal lines L1 and L2 to the speaker circuit 5.

On the other hand, the NOT circuit Q of the reporting device W
7 is connected to the output Y of the flip-flop FF, and one end of the resistor R11 is connected to the negative AND circuit Q7 between the other input of the negative AND circuit Q7 and the output of the negative AND circuit Q7. The resistors R11 and 12 so that they are on the input side of
Are connected in series. Since the output Y of the flip-flop FF is L level, the output of the NAND circuit Q7 becomes H level. Furthermore, H of the NOT circuit Q7
The level output is input to the inverter Q8, and the output of the inverter Q8 becomes L level. The output of the inverter Q8 is connected to the cathode of the light emitting diode LED, and the resistor R13 is connected between the anode of the light emitting diode LED and the power supply Vcc. Since the output of the inverter Q8 is at the L level, the resistor R13 is connected to the resistor R13. A current flows through the light emitting diode LED via the LED, and the light emitting diode LED lights up to indicate that the underwater speaker is not leaking. In addition, between the connection point between the resistors R11 and R12 and the output of the inverter Q8,
A capacitor C5 for blinking the light emitting diode LED when a leakage is detected is connected, and the capacitor C5 is charged from the output of the NAND circuit Q7 via the resistor R12.

On the other hand, when the external water 10 is submerged in the airtight container 1 and water vapor or water drops are applied between the speaker circuit 5 and the sensor 6, the bias voltage applied to the speaker circuit 5 is applied. From the power source Vcc, which is the source, resistors R1, R2 → signal lines L1, L2 → speaker circuit 5 →
A minute current (several microamperes) flows through the route of water → sensor 6 → sensor signal line L3 → detector circuit resistances R1, R2 → ground E. When the minute current exceeds a predetermined current value, the base current of the transistor Q1 satisfies the ON condition, and when the transistor Q1 is turned on, the charging of the capacitor C3 is stopped and the capacitor C3 is charged. The electric charge is discharged through the base of the transistor Q2, and the transistor Q2 is turned off after a certain time delay. This is to prevent malfunction due to inductive noise or the like from the sensor signal line L3.
Is to prevent it from turning off immediately. When the transistor Q2 turns off, the base of the transistor Q3 becomes H level, and the transistor Q3 turns on. Then, the output X of the detection circuit S becomes L level.

Since the output X is L level, the input of the flip-flop FF becomes L level and the output Y of the flip-flop FF becomes H level.

Since the output Y of the flip-flop FF is at the H level, the transistor Q of the breaking device C is
4 is turned on, and a current flows from the power supply Vcc to the coil of the relay RL1. Therefore, the switching circuit of the relay RL1 disconnects the signal lines L1 and L2 from the speaker circuit 5. Therefore, electric leakage is prevented, and a person under water does not receive an electric shock or damage the device.

On the other hand, the output Y of the flip-flop FF
Is H level, the NAND circuit Q of the reporting device W is
7 has an H level, and the other input to which the resistor R11 of the NAND circuit Q7 is connected has an H level. Therefore, the output of the NAND circuit Q7 has an L level.
Further, the input of the inverter Q8 becomes L level,
The output of the inverter Q8 becomes H level. Therefore,
No current flows through the light emitting diode LED, and the light emitting diode LED is turned off. The electric charge charged in the capacitor C5 is discharged to the output terminal of the NAND circuit Q7 via the resistor R12. Then, after a lapse of a certain time, the discharge is substantially completed, the input of the NAND circuit Q7 to which one end of the resistor R11 is connected becomes L level, and the output of this NAND circuit Q7 becomes H level again. Therefore, the input of the inverter Q8 is at the H level and the output is at the L level, so that a current flows through the light emitting diode LED and the light emitting diode LED is turned on. And
From the output of the NAND circuit Q7, the capacitor C
Recharge to 5. In this way, the charging and discharging of the capacitor C5 is repeated, and the light emitting diode LED blinks to indicate that the electric leakage has occurred. Therefore, it is possible to immediately take measures against the intrusion of water into the closed container 1.

As described above, when the inside of the closed container 1 is flooded, the leakage is detected, and the speaker circuit 5 and the signal line L are detected.
Since the disconnection device C cuts off the connection with the L1 and L2, it is possible to prevent electric shock of human beings and the like, and to use the amplifier AMP1.
It is possible to prevent damage such as. Further, by blinking the light emitting diode LED of the notification device W, a person can be informed of the electric leakage. Further, since the bias voltage is simply applied to the speaker circuit via the signal line and the water leakage is detected by the current flowing between the speaker circuit and the sensor, the leakage preventive device can be manufactured with a simple configuration.

Further, since the current does not flow from the bias voltage source in the normal state, there is no energy loss, while only a small current flows from the bias voltage source when the leakage is detected.
Power consumption can be reduced. Further, the sensor may be simply a terminal (only a conducting wire), has a simple structure, and can be manufactured at low cost.

In the above embodiment, the detection circuit S and the breaker C are provided outside the closed container 1, but they may be provided inside the closed container 1 when an internal power source is used.

In the above embodiment, the notification device W is also used.
While the person has been informed of the electric leakage by blinking the light emitting diode LED, the person may be informed of the electric leakage by an alarm sound such as a speaker or a buzzer.

Further, in the above embodiment, the interruption device C disconnects the signal lines L1 and L2 from the speaker circuit 5. However, the power supply of the amplifier AMP1 or all the power supplies may be cut off by the interruption device. The amplifier AMP
When only one power supply is turned off, the bias voltage remains applied to the signal lines L1 and L2, but only a minute current flows and does not affect the human body.

Further, in the above embodiment, an example in which the closed container 1 is put into the water 10 has been described, but the present invention can be applied to the case where a conductive liquid enters the closed container. Is.

Although the contact type electromagnetic relay RL1 is used as the breaking device C in the above embodiment, it is of course possible to use a contactless type semiconductor relay using a transistor or a silicon controlled rectifier. is there. Further, the detection circuit may be composed of an operational amplifier.

[0031]

As is apparent from the above, the leakage preventing device for an underwater speaker according to the present invention connects the two signal lines to which a voltage is applied from the bias voltage source to the speaker circuit in the closed container, and A sensor is provided in close proximity to the speaker circuit, and the current flowing through water between the speaker circuit and the sensor detects leakage in the detection circuit. The input of the drive signal is cut. Therefore, with a simple configuration, it is possible to prevent damage to the speaker circuit and the drive signal source and prevent electric shock to the human body in water.

Further, when the notification device is provided, the notification device receives the leakage detection signal of the detection circuit and can notify the person of the leakage by at least one of the display and the sound.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a leakage prevention device for an underwater speaker according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Airtight container, 5 ... Speaker circuit, 6 ... Sensor, 10
... water, S ... detection circuit, C ... breaker, W ... reporting device, S
P ... Mechanical vibration device, AMP1 ... Amplifier, L1, L2 ...
Signal line, L3 ... Sensor signal line, LED ... Light emitting diode.

Claims (3)

[Claims] 1. A hermetic container having a speaker circuit therein, a bias voltage source, two signal lines connected to the speaker circuit and to which a voltage is applied from the bias voltage source, and in the hermetic container. A sensor provided in the vicinity of the speaker circuit, a detection circuit for detecting electric leakage by a current flowing through water between the speaker circuit and the sensor, and an electric leakage detection signal from the detection circuit, A leakage prevention device for an underwater speaker, comprising: a cutoff device that cuts off a drive signal input to the speaker circuit. 2. The leakage prevention device for an underwater speaker according to claim 1, wherein the detection circuit and the breaker are arranged in the closed container. 3. A reporting device, which receives a leakage detection signal from the detection circuit and notifies the leakage by at least one of a display and a sound.
Leakage prevention device for underwater speaker.