JPH0285997A - Intermittent warning device - Google Patents

Abstract

PURPOSE:To reduce the power consumption of an audible frequency oscillation circuit and a display lamp by storing most of a signal voltage as an electric charge when no oscillation in the audible frequency oscillation circuit which issues an alarm is performed, and emitting the electric charge as a part of the power consumption of the audible frequency oscillation circuit when the audible frequency oscillation circuit oscillates. CONSTITUTION:Power saving is attained by charging a capacitor 35 by the signal voltage at the time of stopping the ringing of a piezoelectric buzzer 7, and supplying the electric charge to the audible frequency oscillation circuit 6 by discharging the electric charge of the capacitor 35 at the time of ringing the piezoelectric buzzer 7, and also, power consumption in an intermittent period can be uniformized. Also, no branch current to light the display lamp 5 is required at the time of ringing the piezoelectric buzzer 7 by permitting the input current of the audible frequency oscillation circuit 6 to flow to the display lamp 5. In such a way, it is possible to reduce the power consumption of the display lamp 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is connected to an abnormality detection circuit of an abnormality alarm device such as a gas leak alarm or a smoke alarm, and is mainly applied to a device that sounds at a location away from the abnormality detection circuit. The present invention relates to an intermittent alarm device that emits a display alarm.

[Conventional technology]

The gas leak alarm supplies an abnormality signal detected by the abnormality detection circuit to an alarm device, causes the alarm device to sound and display an alarm, and warns that there is a gas leak around the abnormality detection circuit. In this case, the alarm device may act in conjunction with the abnormality detection circuit to issue an alarm at that location, but it may also be necessary to issue an alarm at another location, and may be installed at one or more locations away from this location. . Furthermore, if the alarm is issued intermittently, it is likely to attract the attention of the supervisor. A conventional example of such an intermittent alarm device for a gas leak alarm is shown in FIG. In Figure 1,
The intermittent alarm device detects and confirms the signal voltage given to the signal terminal 1゜II by the voltage detection circuit 2 and the delay circuit 3,
A low frequency oscillation circuit 4 having an indicator light 5 and an audio frequency oscillation circuit 6 having a piezoelectric buzzer 7 issue a display and a sound alarm.

The signal generated by the abnormality detection circuit of a gas leak alarm is normally 6V DC during constant monitoring, 12V DC when detecting a gas leak, and becomes Ov when a power outage or disconnection occurs, indicating that the alarm has stopped. . In this way, the intermittent alarm device
6V is always applied between the signal terminals 1° and 1',
In the event of an abnormality, a signal voltage of 12V is applied. A Zener diode 8 is connected between both signal terminals 1 and 11, and the signal voltage is limited to a constant level. The voltage detection circuit 2 is a series circuit of a resistor 9 and a Zener diode 10, and both signal terminals 1
．． 1' is divided, and a constant Zener voltage, here 5V, is applied to one terminal of the comparator circuit 11, and a voltage dividing resistor 12.
The signal voltage divided by 13 is applied to the ten terminals and the threshold voltages are compared.

The output of this voltage detection circuit 2 is connected via a resistor 14 to a connection point of a series circuit of a resistor 15 and a capacitor 16 connected between both signal terminals 1 and 1'. connected to the terminal.

Further, one terminal of the comparator circuit 17 is connected to apply a signal 1 voltage divided by the same voltage dividing resistor 12.13 as one terminal of the comparator circuit 11. The low frequency oscillation circuit 4 is
Each resistor 19, 20° 21, 22, 23 in the differential amplifier 618
It is a multivibrator circuit in which J5 and a capacitor 24 are connected, and the + terminal of the differential amplifier 18 is connected to a diode 25.
It is connected to the output terminal of the comparator circuit 17 via. An indicator light 5 such as a light emitting diode is connected in series with a resistor 23 and between the signal terminal and the output terminal of the differential amplifier 18. In the audio frequency oscillation circuit 6, a series circuit of a resistor 26 and a collector-emitter of a transistor 27 is connected in series with a parallel resonant circuit of a reactor 28 and a capacitor 29, and is connected between both signal terminals 1 and 1', and outputs a child signal. Transistor 27 from terminal 1 via both resistors 30 and 31
connected to the base of.

32 is a diode connected between the parallel resonant circuit of the reactor 28 and capacitor 29 and the base of the transistor 27; 33 is a diode connected between the connection point of both resistors 30 and 31 and the low frequency oscillation circuit 4; It is. The piezoelectric buzzer 7 has its electrodes connected to the connection points between both ends of the parallel resonant circuit and both resistors 30 and 31, and serves as a monitor and a ringer for the circuit 6.

When a voltage of 6■ is constantly applied between both signal terminals 1 and 1', the voltage at the 10 terminal of the comparator circuit 11 is lower than the constant voltage of the -1 terminal, and its output is at a low level, and the delay circuit 3 The output is also at a similarly low level. Therefore, current flows from the + terminal of the differential amplifier 18 to the comparison circuit 17 side, and since the voltage at the + terminal of the differential amplifier 18 is low, the low frequency oscillation circuit 4
does not oscillate. Therefore, the output of the differential amplifier 18 continues to be at a low level, and the indicator lamp 51C4iE current flows due to the voltage 6■ between both signal terminals 1 and 1. The indicator lamp 5 lights up continuously and there is no abnormality in the input signal voltage. Show that. Furthermore, in the audio frequency oscillation circuit 6, since the output of the differential amplifier 18 is at a low level, current flows from the child signal terminal 1 to the differential amplifier 18 via the resistor 30 and the diode 33, and almost no current flows to the base of the transistor 27. tR.

does not flow. Therefore, transistor 27 is not turned on,
Since the audio frequency oscillator does not oscillate, the piezoelectric buzzer 7 does not ring. If there is a gas leak around the abnormality detection circuit (not shown), a 12V abnormality signal voltage is sent from the abnormality detection circuit, and a 12V signal voltage is applied between both signal terminals 1.1' of the intermittent alarm device. be done. Then, the voltage at the ten terminals of the comparator circuit 11 becomes higher than the constant voltage at the one terminal, and the output of the comparator circuit 11 becomes high level. This output voltage is resistor 1
Since the capacitor 16 is charged through the comparator circuit 1
When the charging of the capacitor 16 is almost completed, the voltage at the terminal 7 becomes higher than that of the other terminal, and the output of the comparator circuit 17 becomes a high level later than the output voltage of the comparator circuit 11. In this way, malfunctions caused by pulses other than the abnormal signal voltage are prevented. When the output of the comparator circuit 17 becomes high level, the current flowing from the terminal of the differential amplifier 18 to the comparator circuit 17 is blocked by the diode 25,
The voltage at terminal 8 rises, and this low frequency oscillation circuit 4 becomes
Starts low frequency oscillation of about several Hz. Therefore, indicator light 5
goes off when the output of the differential amplifier 18 is at a high level,
lζ lights up when the level is low. That is, the flashing of the indicator light 5 gives an alarm that the abnormality detection circuit has generated an abnormal signal. Also, at this time, the resistance is 30. The current flowing in the direction of the differential amplifier 18 via the diode 33 also becomes an intermittent current depending on the level of the oscillation output of the differential amplifier 18. During the period when no current flows through the diode 33, the transistor 27 is connected to the base 'It through both resistors 30 and 31.
Current flows and transistor 27 is turned on. In this way, the audio frequency oscillation circuit 6 includes the piezoelectric buzzer 7 and the reactance 2.
The piezoelectric buzzer 7 oscillates at an audible frequency determined by the parallel resonant circuit of the piezoelectric buzzer 8 and the capacitor 29. Of course, when current is flowing through the diode 33, the transistor 2
7 is off, the audio frequency oscillator 6 does not oscillate and the piezoelectric buzzer 7 does not ring. Therefore, the audio frequency oscillation circuit 6 vibrates intermittently to cause the piezoelectric buzzer to ring intermittently.

Of course, if the signal voltage is cut off due to a power outage or disconnection, the indicator light 5
is turned off and the piezoelectric buzzer 7 does not sound.

[Problem to be solved by the invention]

However, the piezoelectric buzzer has a drawback in that it consumes a lot of power in order to make the volume sufficiently loud. Therefore, there is a large difference in power consumption when the piezoelectric buzzer is ringing and when it is stopped. Furthermore, if a plurality of intermittent alarm devices are connected to one abnormality detection circuit in order to generate an alarm at a location different from the location where the abnormality occurs, there is a drawback that the signal voltage decreases when the piezoelectric buzzer rings, resulting in malfunction. Furthermore, this device
The disadvantage is that the current for the indicator light is shunted separately from other circuits and a portion of the power of the flow signal voltage is dissipated.

The present invention aims to save power when the piezoelectric buzzer rings and the indicator light, can reliably drive multiple units with one abnormality detection circuit, can be installed externally away from the abnormality detection circuit, and the piezoelectric buzzer An object of the present invention is to provide an intermittent alarm device that averages the power consumption when the alarm is ringing and when it is stopped.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a signal terminal to which a signal voltage is applied, a voltage detection circuit that detects the signal voltage, and a low frequency oscillation circuit that vibrates the output bottom pressure by the signal voltage. a circuit, a capacitor charged by the signal voltage, an indicator light, a piezoelectric buzzer, and an audio frequency oscillation circuit that is connected to oscillate when the output voltage of the low frequency oscillation circuit is high and causes the piezoelectric buzzer to sound. The audio frequency oscillation circuit is characterized in that the audio frequency oscillation circuit is driven by the signal range pressure and the charge t11 voltage of the capacitor via the indicator light.

[Effect]

When the piezoelectric buzzer stops ringing, a capacitor is charged by the signal voltage, and when the piezoelectric buzzer is ringing, the charge in this capacitor is discharged and supplied to the audio frequency oscillation circuit to save power and average the power consumption between intermittent cycles. do. In addition, the indicator lamp allows one input current of the audio frequency oscillation circuit to flow therethrough, so that a shunt current for lighting the indicator lamp is not required when the piezoelectric buzzer sounds.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 2 and 3. 2 in FIG. 2, the intermittent alarm device is
Both signal terminals 1, 1', voltage detection circuit 2, and delay circuit 3
It consists of a low frequency oscillation circuit 4 and an audio frequency oscillation circuit 6, and a signal voltage is applied to both signal elements 1 and 1' to issue a lighting and sounding alarm.

Of these, the two signal terminals 1, 1', the voltage detection circuit 2, and the delay circuit 3 are completely the same as those of the conventional ones, so their explanation will be omitted. The low frequency oscillation circuit 4 also has a differential amplifier 18 and resistors 19, 20°, zt, zz, z, almost the same as the conventional one.
It is a multivibrator circuit in which ag and a capacitor 24 are connected, and the + terminal of the differential amplifier 18 is a diode 25.
It is connected to the output terminal of the comparator circuit 17 via. However, since the indicator lamp 5 connected in series with the resistor 23 is transferred to the audio frequency oscillator circuit, this resistor 23 can have a high resistance value to reduce this current. The audio frequency oscillation circuit 6 is similar to the conventional one in that it is connected in series with a parallel resonant circuit of a reactor 28 and a capacitor 29 to a series circuit of a resistor 26 and the collector Φ emitter of a transistor 27, but An indicator light 5 is connected in series to one end, and both ends of this series circuit include a resistor 34 and a capacitor 35.
A resistor 3 connected in series between both signal terminals 1 and 1'
4 and the connection point between capacitor 35 and one signal terminal 1'. The base of the transistor 27 is connected to the child signal terminal 1 via a series resistor 30, 31 as before, and the diodes 32, 33 are also connected as before. Note that the connection point between the indicator light 5 and the resistor 26 is connected to the output terminal of the comparator circuit 17 via the resistor 36. The piezoelectric buzzer 7 has its electrodes connected to both ends of the parallel resonant circuit and the connection points of the resistors 30 and 31, respectively, as conventionally, and serves as an excavator for the circuit 6 and as a ringer.

When a voltage of 6cm is constantly applied between the signal terminals 1 and 1', the output of the voltage detection circuit 2 is at a low level as in the conventional case, and the output of the delay circuit 3 is also at a low level. . Therefore, the low frequency oscillation circuit 4 is not excavated. Furthermore, the audio frequency oscillation circuit 6 is not excavated and the piezoelectric buzzer does not sound. However, since the output of the comparator circuit 17 is at a low level, the indicator light 5 continues to light up due to a current flowing in the direction of the resistor 34, indicator light 5, and comparison circuit 17, indicating that there is no abnormality in the signal voltage.

If a signal voltage of 12V is applied between the compensation terminals 1 and 1', the low frequency oscillation n-path 4 oscillates as described above. Further, the capacitor 35 is charged via the resistor 34. In this way, when the low frequency oscillation circuit 4 excavates and the output of the differential amplifier 18 becomes high level, the transistor 27 turns on and the indicator lamp 5 lights up as already mentioned, and the audio frequency oscillation circuit 6 excavates, The piezoelectric buzzer 7 sounds. Next, when the output of the differential amplifier 18 becomes low level, the transistor 27
is turned off, the indicator light 5 goes out, the audio frequency oscillation circuit 6 stops oscillating, and the piezoelectric buzzer 7 stops ringing.

The blinking of the indicator lamp 5 and the ringing and stopping of the piezoelectric buzzer 7 are intermittently repeated depending on the frequency of the low frequency oscillation circuit 4. During this time, since the output of the comparison circuit 17 is at a high level, no current flows through the resistor 36.

That is, the indicator light 5 is blinked only by the drive current of the audio frequency oscillation circuit 6.

When the audio frequency oscillation circuit 6 repeatedly stops oscillating due to the vibration of the low frequency oscillation circuit 4, the current waveforms at the main points of the audio frequency oscillation circuit 6 are illustrated with time T plotted on the horizontal axis as shown in FIG. AJ, like (B).

Figure 3 (A) shows the conventional input region current Ii and transistor 2.
7 and the current It, and these two currents are approximately equal. When the current It flows through the transistor 27, the audio frequency oscillator 6 excites and the piezoelectric buzzer 7 sounds. In FIG. 3, (Bl indicates the current of the main part according to the present invention, the current It of the transistor 27 is almost the same as that of the conventional one, and the piezoelectric buzzer 7 is made to sound by this current It. At this time, the capacitor 35 is discharged. Since the current Id is added, input 1
1C flow If becomes smaller as shown in the figure. Ic shown by a dotted line in FIG. 1 is a charging current of the capacitor 35, and its actual direction is opposite to the discharging current Id. In this way, the capacitor
It is charged when the alarm device does not sound, and discharges when it sounds, supplying part of the power when the audio frequency oscillation circuit vibrates, thereby saving power and averaging power consumption.

〔Effect of the invention〕

As described above, the intermittent alarm device according to the present invention stores most of the signal voltage as a charge when the audio frequency oscillation circuit that issues the alarm does not excavate, and when the audio frequency detection circuit oscillates, this charge is transferred to the indicator light. The power consumption of the audio frequency excavation circuit is emitted as part of the power consumption of the audio frequency excavation circuit, thereby saving the power consumption of the audio frequency oscillation circuit and the power consumption of the indicator light. Therefore, this intermittent alarm device can increase the sound of the piezoelectric buzzer, and connect a plurality of external intermittent alarm devices to the same abnormality detection circuit outside the alarm device that is conjugated with this abnormality detection circuit, It is an excellent device that can also send alarms at different locations.

[Brief explanation of the drawing]

Figure 1 is a wiring diagram showing an example of a conventional intermittent alarm device;
The figure is a wiring diagram showing an embodiment of an intermittent alarm device according to the present invention,
Figure 3 shows the current waveform of the audio frequency oscillation circuit.
) is a conventional input and transistor 1.1'...signal terminal, 2...voltage detection circuit, 4...low frequency oscillation n-path, 5
... Indicator light, 6 ... Audio frequency oscillation circuit, 7 ... Piezoelectric buzzer 35 ... Capacitor.

Claims (1)

[Claims] 1) A signal terminal to which a signal voltage is applied, a voltage detection circuit that detects the signal voltage, a low frequency oscillation circuit that oscillates the output voltage by the signal voltage, a capacitor that is charged by the signal voltage, and an indicator light. a piezoelectric buzzer; and an audio frequency oscillation circuit that is connected to oscillate when the output voltage of the low frequency oscillation circuit is high and causes the piezoelectric buzzer to sound; An intermittent alarm device, characterized in that the intermittent alarm device is connected to be driven by a signal voltage and a charging voltage of the capacitor.