JPS5934957Y2 - Electronic sound generation circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic sound generating circuit, and more particularly to an electronic sound generating circuit that uses an audible electronic sound that is different from the normally instantaneous electronic sound to notify a power outage during a power outage.

Currently, there are two types of sounding devices: contact type buzzers and electronic buzzers, and the buzzer sound emitted from the electronic buzzer is called an electronic sound.

This electronic buzzer is an electro-acoustic transducer that emits a specific audible frequency without electrically moving parts or contacts, and it is also made of a piezoelectric type that uses the electrostrictive phenomenon of piezoelectric materials and a magnetic coil. It can be classified into two types: the electromagnetic type, which causes vibrations on the diaphragm.

Compared to contact-type buzzers, this electronic buzzer has the advantage of being highly reliable and producing no sparks because it has no contacts, and therefore there is no risk of failure or interference even when it is incorporated into various electronic circuits.

Furthermore, it has excellent features such as being able to easily control the type of sound, such as timbre and sound pressure, with a single electronic circuit.

The present invention provides an electronic sound generation circuit using such an electronic buzzer as a sounding body, which can be incorporated into, for example, refrigerator-freezers, medical stockers, etc., and can be used to notify when the door is ajar or when the door is left open for a long time. This system is equipped with an alarm function to notify the user that the stored items are being damaged, and a power outage alarm function in the event of a power outage, and an electronic sound will be used to notify the user of the prevention of spoilage of stored items.

A detailed description will be given below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the present invention, in which 1 is a sounding body consisting of an electronic buzzer, 2 is an oscillation circuit that supplies oscillation output to the sounding body 1 and causes the sounding body 1 to emit an electronic sound, and 3 is a sounding body consisting of an electronic buzzer. An oscillation control circuit that controls the oscillation state of the oscillation circuit 2 and determines the tone, sound pressure, etc. of the electronic sound; 4 is a power supply circuit that includes a transformer or the like that transforms the commercial power supply 5 to a desired voltage value; supplies power to the oscillation control circuit 3 and the oscillation circuit 2, and these power supply circuit 4, oscillation control circuit 3, oscillation circuit 2, and sounding body 1 form one sound generation system.

Reference numeral 6 denotes a power supply circuit during a power outage that directly supplies voltage to the oscillation circuit 2 during a power outage of the commercial power supply 5; this power supply circuit 6 is associated with the power supply circuit 4, so that the power supply circuit 6 is connected to the power supply circuit 4;
The power supply circuit 6, the oscillation circuit 2, and the sounding body 1 form a sound generation system during a power outage.

Next, the operation will be explained using a specific circuit diagram as shown in FIG.

AC ioo v is applied from a commercial power source 5 to the primary side of the transformer T of the normal power supply circuit 4 .

Connected to the secondary side of the transformer T are rectifier circuits 7 and 8 consisting of diodes and smoothing capacitors for supplying DC voltage to each of the two sound generating systems.

One of the rectifier circuits 7 is connected to the oscillation control circuit 3 via a normally open switch SW that opens and opens in conjunction with the opening and closing of the door.

This oscillation control circuit 3 includes a CR integration circuit 9, a Schmitt circuit 10, and a power supply control transistor Tr1.The control output of this oscillation control circuit 3 is output after a certain period of time, for example, 30 seconds, as shown in FIG. 3A. Its output is inverted from low level to high level.

The oscillation circuit 2 is a circuit in which the sounding body 1 is used as an electromagnetic buzzer, and the oscillation circuit 2 is a circuit that generates a so-called intermittent sound that periodically stops the oscillation operation. When the control output is applied, that is, when the door is opened and the normally open switch SW is closed, the transistor Tr3 in the latter stage of the Schmitt circuit 10 constituting the oscillation control circuit 3 turns ON, and the base potential of the power supply control transistor Tr1 becomes low level. Therefore, the control voltage of the power supply control transistor Trl is also at a low level, and the sounding element 1 emits only intermittent electronic sounds of low sound pressure.

After that (after 30 seconds), the transistor Tr2 at the front stage of the Schmitt circuit 10 is turned on by the charged charge gradually charged in the capacitor C of the CR integration circuit 9, and the transistor Tr3 at the rear stage is turned off, and the power supply control transistor Trl is turned on.
The base potential of is inverted to high level.

That is, a high level control output is supplied to the oscillation circuit 2, and the third
As shown in FIG. B, the sounding body 1 emits intermittent electronic sounds of high sound pressure.

Therefore, when this electronic sound changes from a low sound pressure to a high sound pressure, the user is alerted to the fact that the door has been open for a long time or is notified that the door is in an ajar state.

Further, for a more detailed explanation of the oscillation control circuit 3 and the oscillation circuit 2, see Utility Model Application No. 1983-8, which the applicant has already filed.
See No. 3332.

Next, the operation during a power outage will be explained.

The power supply circuit 6 at the time of a power outage includes a secondary battery B connected to the transformer T of the power supply circuit 4 and the rectifier circuit 8, and two diodes DL D2 and 2nd, the emitter of which is connected to the positive side of the secondary battery B. is connected to the switching transistor Tr4 connected to the oscillation circuit 2 and the bias resistor R interposed between the collector and base of the transistor Tr4.

When power is supplied from the commercial power source 5, a current Ic flows from the rectifier circuit 8 through the secondary battery B and the first diode D1, and the secondary battery B is charged.

When this secondary battery B is sufficiently charged, a current flows through the bias resistor R.

However, while the commercial power supply 5 is supplying power, the ○ terminal of the rectifier circuit 8 is at a negative voltage, so the current flowing through the current Ic and the resistor R flows into the ○ terminal of the rectifier circuit 8 and becomes the base of the switching transistor Tr4. is not supplied.

Therefore, the transistor Tr4 is turned off and the power supply to the oscillation circuit 2 is cut off.

This can be said from the following.

That is, assuming that the transistor Tr4 is turned on when the commercial power supply 5 supplies power, the relationship between the base voltage VB and the emitter voltage VE of the transistor Tr4 is VB>VE.

On the other hand, when the transistor Tr4 is turned on, the rectifier circuit 8 connects the transistor Tr4, the oscillation circuit 2, the diode D2 .
A current flows back to the rectifier circuit via DI.

Therefore, the above-mentioned VE becomes higher than the O terminal voltage of the rectifier circuit and eventually becomes higher than the base voltage VB, which contradicts the above assumption.

Therefore, transistor Tr4 is not ONL.

Next, when the commercial power supply 5 is out of power, a base current flows from the secondary battery B to the base of the switching transistor Tr4 via the bias resistor R, and this transistor Tr4 is turned on.
do.

That is, from the secondary battery B to the switching transistor Tr
A voltage is supplied to the oscillation circuit 2 through the power supply 4 to form a sound generation system during a power outage.

Therefore, the sounding body 1 intermittently emits a high sound pressure electronic sound regardless of whether the door is opened or closed to notify that a power outage has occurred.

It should be noted that the high sound pressure electronic sound generated by power supply from the power supply circuit 6 during a power outage may have a higher level of sound pressure than the normal oscillation sound, that is, the low sound pressure oscillation sound produced when power is supplied from the commercial power supply 5. Bye.

Therefore, even if the sound pressure level generated by power supply from the power supply circuit 6 during a power outage is the same as the sound pressure level of the door ajar alarm, if a high sound pressure electronic sound is emitted, the door and commercial power By checking step 5, it is possible to know whether the door is ajar or whether there is a power outage in the commercial power supply 5, and appropriate measures can be taken promptly.

As is clear from the above description, the electronic sound generation circuit of the present invention has the following features:
It is equipped with a sounding system that operates normally and a sounding system that sounds during a power outage, and the sounding circuit is normally controlled by an oscillation control circuit, and the electronic sound determined by the oscillation control circuit is emitted from the sounding body. During a power outage, voltage is supplied directly from the power supply circuit during a power outage to the oscillator circuit, causing it to emit an electronic sound that is different from normal electronic sounds, so it is possible to quickly notify that a power outage has occurred, such as in refrigerators, refrigerators, and medical stockers. By incorporating it into a storage, etc., it is possible to take some measures to prevent refrigerated (frozen) stored items from spoiling.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the electronic sound generating circuit of the present invention, Fig. 2 is an electric circuit diagram showing its specific circuit, and Fig. 3 is a waveform diagram for explaining the operation. 2 is an oscillation circuit, 3 is an oscillation control circuit, 4 is a power supply circuit, 5 is a commercial power supply,
Reference numeral 6 indicates a power supply circuit during a power outage, B indicates a secondary battery, and Tr4 indicates a switching transistor.

Claims (1)

[Scope of utility model registration request] A sounding body that emits an electronic sound, an oscillation circuit that operates the sounding body, an oscillation control circuit that controls the oscillation state of the oscillation circuit, a commercial power supply connected to the control circuit, and a power supply from the commercial power supply. It has a secondary battery for charging, and when a power outage in the commercial power supply is detected, the secondary battery is disconnected from the power outage power supply circuit that supplies power to the oscillation circuit, and the oscillation circuit normally connects to the commercial power supply via the oscillation control circuit. The sounding body oscillates depending on the voltage supplied from the power supply, and emits an electronic sound according to the oscillation output.At the same time, in the event of a power outage, the oscillation circuit is directly supplied with voltage from the power supply circuit during power outage, and the sound is different from the normal electronic sound. An electronic sound generation circuit characterized in that it generates distinguishable electronic sounds.