JP2000206975A - Alarm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alarm device simply changing a scale, a tone color and the volume and smoothly muffling an alarm sound without a shutter. SOLUTION: An inverter circuit 2 outputs pulse power to a motor 3 to rotation drive it. Since an inverter control circuit 6 controls a base drive signal s3 to the inverter circuit 2, the output voltage and the frequency of the inverter circuit 2 are varied freely. Thus, the scale, the timbre and the volume of a siren sound are changed, and the alarm device generates various timbres. Further, since the motor 3 is braked by the inverter circuit 2, a siren sound is muffled smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device that emits an alarm sound of a siren, and more particularly to an alarm device that can easily change the scale, tone, and volume of an alarm sound and that does not use a mechanical shutter. The present invention relates to an alarm device that can mute sound smoothly.

[0002]

2. Description of the Related Art Conventionally, an alarm device which drives a motor siren to emit an alarm sound has been used in order to notify the alarm sound of the siren to the surrounding residents.

FIG. 6 is an example of a block diagram of a conventional alarm device. The power supply is a general commercial three-phase AC power supply, and is connected to the motor 3 via the electromagnetic switch 9. The motor 3 is an AC three-phase induction motor. And motor 3
Includes a siren unit 4 that emits an alarm sound and a shutter 8 that shuts off the alarm sound.

The pattern signal generating circuit 5 to which the siren drive signal s1 is inputted is composed of a pattern generating section 5B1, an AND circuit 5B2 and an inverting circuit 5B3. The pattern generating section 5B1 repeatedly outputs a signal of a constant alarm pattern (sounding pattern). AND circuit 5B2
Outputs the logical sum of this signal and the siren drive signal s1 as a pattern signal s2. The inverting circuit 5B3 inverts the pattern signal s2 and sends it to the shutter 8 as a shutter drive signal s4.

FIG. 7 is a timing chart of each signal of the conventional alarm device. (A) is a siren drive signal s
1, (b) shows a pattern signal s2, (c) shows a shutter drive signal s4, (d) shows a change in the number of revolutions of the motor 3, and (e) shows a power supply timing to the motor 3.

[0006] The siren drive signal s1 is a signal input for a relatively long period of time in units of minutes.

The pattern signal s2 is a logical sum signal of the siren drive signal s1 output from the AND circuit 5B2 and the alarm pattern generated by the pattern generator 5B1, and thus has a waveform as shown.

The electromagnetic switch 9 shown in FIG.
The motor 3 is opened during the OFF period and closed during the ON period.
Is controlled as shown in FIG.

When three-phase AC power is supplied to the motor 3,
The rotation speed of the motor 3 increases, and reaches a rated rotation speed in about 5 seconds as shown in FIG. Electromagnetic switch 9
When the power supply is cut off, the motor 3 rotates for a while with the kinetic energy (inertial energy) of the remaining rotor and then stops. The motor stops after about 90 seconds as shown.

As described above, even after the power supply is stopped, the motor 3 rotates and the alarm continues to sound.
The shutter 8 shields this sound.

The shutter drive signal s4 shown in (c) is an inverted signal of the pattern signal s2, and is turned on during the rest period of the pattern signal s2 to operate the shutter 8. That is,
During a period in which power is not supplied to the motor 3, the shutter 8 is operated to block the remaining alarm sound.

[0012]

As described above, since the conventional alarm device is directly driven by the commercial three-phase AC power supply, it can generate only a sound of a specific scale based on the commercial frequency. , Could not generate various tones.

Further, since the alarm sound is cut off by using a mechanical shutter, the size of the alarm device is increased, and the manufacturing cost is increased due to the necessity of manufacturing the alarm device individually according to the shape of the siren portion.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an alarm device which can easily change the scale, tone and volume emitted by the alarm device, and can smoothly mute the alarm sound without using a shutter.

[0015]

The alarm device according to the present invention comprises:
An AC motor, a siren that sounds in accordance with the rotation of the AC motor, an inverter circuit that drives the AC motor, and an inverter control circuit that supplies a rotation control signal of the AC motor to the inverter circuit in response to an alarm command And characterized in that: That is, the present invention is intended to easily change the scale, tone, and volume of the alarm sound generated by the siren by controlling the AC motor with an inverter, and to smoothly muffle the sound of the siren during braking. Things. By changing the frequency applied to the AC motor by the inverter and changing the number of revolutions of the AC motor, it is possible to change the scale of the siren and to configure various timbres. In addition, by stopping the rotation of the AC motor by the inverter at the time of braking, the sound of the siren can be muted smoothly.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the alarm device according to the present invention will be described below in detail with reference to FIGS. still,
The same components as those of the conventional alarm device are denoted by the same reference numerals, and the detailed description is omitted.

FIG. 1 is a circuit diagram showing a first embodiment.

In this embodiment, a variable voltage variable frequency inverter is provided between a three-phase AC power supply and an AC motor, and a shutter attached to a siren unit of a conventional device is omitted. Other parts are the same as the conventional alarm device.

Hereinafter, this circuit will be described in detail.

The three-phase AC power supply has a rectifying diode D1.
6 and a smoothing electrolytic capacitor C1 are connected to convert a three-phase alternating current into a direct current.

An inverter circuit 2 is connected to both ends (DC power supply) of the electrolytic capacitor C1.
Is connected. The motor 3 has a siren 4
Is provided.

The inverter circuit 2 has six parallel circuits in which the collector of the driving transistor and the cathode and the emitter and the anode of the diode are respectively connected.
Each transistor is denoted by Q1,..., Q6, and each diode is denoted by D7,. The base of each transistor is connected to the inverter control circuit 6.

The power consumption circuit 7A includes an electrolytic capacitor C1.
And are provided in parallel. This circuit is for causing the regenerative power generated when braking the motor 3 to be consumed by the resistor R1. One end of the resistor R1 is connected to the positive side of the DC power supply, and the other end is connected to the collector of the transistor Q7. The emitter of the transistor Q7 is connected to the negative side of the DC power supply.

The pattern signal generating circuit 5 comprises a pattern generating section 5B1 and a VF command signal forming circuit 5B4. The pattern generation section 5B1 generates a constant alarm pattern (sounding pattern) signal, and has data (not shown) relating to the output voltage vo of the inverter circuit 2 and the frequency f. The VF command signal forming circuit 5B4 modulates the command value of the output voltage vo and the frequency f input by the operator, superimposes the command value on the pattern signal s2 (VF command), and sends it to the inverter control circuit 6.

The inverter control circuit 6 controls the pulse width and frequency of the base drive signal s3 (six signals),
A circuit for sending out to the bases of the transistors Q1 to Q6,
It is controlled by a microcomputer (not shown).

FIG. 2 is a timing chart of each signal in the circuit shown in FIG.

FIG. 3A shows an external input signal as in the case of the conventional siren drive signal s1, which is a signal for instructing an audible alarm during the ON period. This signal is
The signal is input to the pattern signal generation circuit 5.

FIG. 3B shows a pattern signal s2 output from the pattern signal generation circuit 5. This is schematically shown for easy understanding, and a signal including a command value of the inverter output voltage vo and the frequency f is not shown. This pattern signal s2 is input to the inverter control circuit 6. The pattern signal s2 is not limited to the one shown in FIG.
Various forms such as a mixed pattern of long and short ON periods are included. As a result, a continuous sound or an intermittent sound can be arbitrarily emitted, so that the alarm effect can be enhanced and the contents of the alarm can be easily transmitted.

FIG. 3C shows a change in the number of revolutions of the motor 3. In this embodiment, the rotation speed and the time required for braking can be freely changed by the operation of the inverter control described later.

FIG. 3D shows a period during which power is supplied to the motor 3. In this embodiment, since the inverter drive using the inverter circuit is performed, power is always supplied to the motor 3 while the motor 3 rotates.

FIG. 3 shows ON / OFF timings of the transistors of the inverter circuit 2. Here, the frequency control and the output voltage control are performed simultaneously, so that the output voltage is subjected to pulse width modulation (PWM). By making the modulation sinusoidal, low-order harmonics can be removed, so that the torque ripple of the motor 3 can be reduced.

FIG. 3A shows the triangular wave carrier signal e and the sine wave signals eu, ev, ew of each phase serving as a voltage command, and are compared by a comparison circuit (not shown). When the sine wave signal level is higher than the triangular wave carrier signal, the upper transistor of the inverter circuit unit 2 is turned on.
If it is low, the lower transistor is turned on. FIGS. 3B, 3C and 3D show the U-phase (Q1, Q4), V-phase (Q2, Q5) and W-phase (Q
3, Q6) showing the ON / OFF timing of the transistor. Thereby, the inverter circuit 2
3 (e) is obtained between the U-phase and the V-phase.

In order to simultaneously vary the output voltage and frequency of the inverter circuit 2, the amplitude and frequency of the sine wave signal may be varied by the pattern signal s2 (VF command) of the pattern signal generation circuit 5.

In this embodiment, the inverter circuit 2 and the inverter control circuit 6 constitute a variable voltage variable frequency inverter (VVVF inverter).

FIG. 4 shows the characteristics of the output voltage vo and the frequency f of the VVVF inverter.

In this embodiment, under the control of the inverter control circuit 6, control for keeping the ratio between the frequency f and the output voltage vo constant (V / f constant control) is performed.

When the motor 3 is started, the output voltage vo and the frequency f are gradually increased, and from the point a to the point b in 5 seconds.
Accelerate to reach. That is, from a frequency of 0 Hz (motor rotation speed 0 rpm) to 100 Hz (3000 rpm)
About 5 seconds is enough to accelerate to On the other hand, during braking, the point b to a are changed within 5 seconds. That is, the time from 3000 rpm to the stop of rotation (braking time) is about 5 seconds. Note that the output voltage vo and the frequency f are varied according to the scale, timbre, and volume generated by the siren unit 4.

In this embodiment, the power supply to the motor is not cut off by the electromagnetic switch as in the conventional alarm device, but the output voltage and the frequency to the motor 3 are reduced by the inverter circuit 2. Therefore, during braking, regenerative power is fed back from the windings of the motor 3 to the inverter circuit 2 during braking. This power is
The current i shown in FIG. 1 is generated to increase the voltage V of the DC power supply (the voltage across the electrolytic capacitor C1). This voltage increase causes an overvoltage in the converter circuit 1 and the inverter circuit 2.

Therefore, in this embodiment, a power consumption circuit 7A is provided to avoid this voltage rise. In this circuit, regenerative power generated during braking is consumed by the resistor R1. That is, when the DC voltage V rises, the inverter control circuit 5 monitoring the DC voltage V supplies the base current ib to the transistor Q7. This base current i
b turns on the transistor Q7, and the current i flows through the resistor R1.
, The regenerative power can be converted to heat and consumed. Therefore, it is possible to avoid unnecessary rise of the DC voltage V and to perform smooth braking, and also to mute the alarm sound smoothly in a short time. In addition, since there is no need to attach a mechanical shutter, which is necessary for the conventional alarm device, the device can be reduced in weight and size.

In the V / f constant control of the inverter control circuit 6, the time until the rotation is stopped is increased, and FIG.
As shown in (c), the braking time of the motor 3 is increased (> 5 s).
ec), the lingering sound can be lengthened like a bell sound.

In the first embodiment of the alarm device of the present invention, the regenerative electric power is reduced while the number of rotations of the motor is reduced by an inverter circuit, instead of opening the power supply path for driving the motor. Perform regenerative braking for recovery (consumption). Therefore, the alarm sound can be silenced in a short time, and conversely, the time until silence can be extended like a bell sound.

In the first embodiment described above, the inverter circuit 2 is provided with the power consuming circuit 7A.
Although the regenerative power is consumed by the resistor R1, it is possible to recover the regenerative power without reducing the effective efficiency by returning the regenerative power to the three-phase AC power supply.

FIG. 5 is a partial configuration diagram showing a second embodiment of the present invention. In this embodiment, a current feedback circuit 7B is provided instead of the power consumption circuit 7A used in the first embodiment. In addition, the inverter circuit 2, the motor 3,
The siren unit 4 and the pattern signal generation circuit 5 operate in the same manner as the operation in the first embodiment. Therefore, illustration and description are omitted.

The current feedback circuit 7B includes transistors Q8 to Q8.
13 is provided. For the transistors Q8 to Q10, the collector is connected to the DC power supply side, that is, the positive side of the electrolytic capacitor C1, and the emitter is connected to each phase of the three-phase AC power supply. For the transistors Q11 to Q13, the emitter is connected to the negative side of the electrolytic capacitor C1. And a collector connected to each phase of the three-phase AC power supply.

As such a circuit configuration, the transistor Q
By controlling the bases 8 to 13 by the inverter control circuit 6, the regenerative power can be fed back to the three-phase AC power supply to avoid an increase in the voltage V of the DC power supply.

Therefore, in the second embodiment, the current feedback circuit returns the regenerative electric power from the motor to the three-phase AC power supply, so that energy-saving and smooth braking of the motor can be performed. That is, the alarm sound can be smoothly muted.

As described above, the alarm device of the present invention speeds up the rotation of the motor by the inverter circuit when starting the siren, while recovering the regenerative power of the motor during braking by using the power recovery circuit (power consumption circuit or power consumption circuit). The inverter control circuit operates so as to be recovered by the current feedback circuit. Therefore, it is possible to easily change the scale and timbre of the siren by changing the number of revolutions of the motor, and it is also possible to generate intermittent sounds. In addition, the motor can be braked smoothly by avoiding the effect of regenerative power generated during braking, and the alarm can be muted smoothly. Therefore, the shutter required for the conventional alarm device becomes unnecessary, and the alarm device can be reduced in size and weight.

[0048]

According to the alarm device of the present invention, since the motor is driven to rotate by the inverter circuit, the scale, tone and volume of the siren can be easily changed.
On the other hand, at the time of braking, the inverter control circuit causes the power recovery circuit to recover the regenerative electric power of the motor, so that the motor can be braked smoothly by avoiding the influence of the regenerative electric power, and the alarm can be muted smoothly. Accordingly, a shutter is not required, and the size and weight of the alarm device can be reduced.

Further, by adjusting the braking time of the motor, the length of the silencing time of the alarm sound can be changed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a first embodiment of an alarm device according to the present invention.

FIG. 2 is a timing chart of each signal of the device shown in FIG.

FIG. 3 shows the ON / OFF state of the transistor in the device shown in FIG.
It is a timing chart of OFF.

4 is a characteristic diagram of an output voltage and an output frequency of an inverter circuit of the device shown in FIG.

FIG. 5 is a partial configuration diagram of a second embodiment of the alarm device according to the present invention.

FIG. 6 is an example of a block diagram of a conventional alarm device.

7 is a timing chart of each signal of the device shown in FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Converter circuit 2 Inverter circuit 3 Motor 4 Siren part 5 Pattern signal generation circuit 6 Inverter control circuit 7A Power consumption circuit 7B Current feedback circuit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Morio Matsushita 3-6 Kanda Nishikicho, Chiyoda-ku, Tokyo F-term (reference) 5C087 AA33 AA34 AA46 EE01 FF02 FF06 FF09 FF12 GG06 GG20 GG30 GG55 GG69 GG79 5H576 AA20 BB02 BB03 BB04 CC05 DD02 DD04 EE04 EE09 EE11 EE17 FF02 FF03 FF04 GG04 HA02 HB02 KK08 LL24 MM03

Claims (5)

[Claims] An AC motor; a siren that sounds in accordance with a rotation operation of the AC motor; an inverter circuit for driving the AC motor; and a rotation control signal of the AC motor to the inverter circuit in response to an alarm command. An alarm device, comprising: an inverter control circuit that provides the following. 2. The alarm device according to claim 1, further comprising a power recovery circuit that recovers regenerative power from the AC motor. 3. The alarm device according to claim 2, wherein the power recovery circuit consumes the regenerated power by an impedance element. 4. The alarm device according to claim 2, wherein the power recovery circuit returns the regenerative power to a power supply of the inverter circuit. 5. The alarm command according to claim 1, wherein the alarm command is a command for controlling at least a frequency output from the inverter circuit to the motor.
The alarm device according to item 1.