JPS6216708Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a watch with a buzzer, such as an alarm watch.

An alarm clock or a clock with a timer that notifies you when the set time has arrived is a very convenient feature.

However, in the past, the volume level of the buzzer, which is the source of sound, was fixed, and there were many inconveniences such as the volume being insufficient in a crowded environment or being too loud during a quiet meeting.

The purpose of this invention is to improve the above points, and to construct a watch with a buzzer that automatically controls the volume of the buzzer according to the noise level of the surrounding environment, and that is reliable and does not disturb others. .

The present invention will be explained in detail below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention for automatic level setting of a buzzer.

1 is a noise level detection means, 2 is an analog processing means for the output of 1, 3 is an A/D conversion means, 4 is a digital processing means, 5 is a volume control means, and 6 is a buzzer. The functions configured in this block diagram operate only when the clock section outputs an alarm time arrival output, and normally does not consume power.

A microphone may be used as the noise level detection means 1, but for simplicity, a buzzer, which is an electro-mechanical converter, may be used to obtain an electrical output. In this case, the noise level is measured by the buzzer before sounding the buzzer, so in terms of time, the noise level is measured and memorized first, and then the buzzer driving means 4 to 6 and the buzzer are used to measure the noise level. Occur.

The analog processing means No. 2 includes an amplifying circuit for the output from No. 1 and an integrating circuit for taking an average over a certain period of time. The digital processing means 4 is a circuit that stores a digital output of the measured noise level and calculates the output plus how many louder volumes the buzzer should sound. In practice, to reduce the number of circuit elements, several types of buzzer drive levels are created and it is determined which drive level to select based on the noise level.

Figure 2 shows the display panel display of the embodiment of the present invention, and is an example in which the amount of noise is displayed as 56 phons, and with this configuration, it can also be used as a sound level meter. . The place where the number 56 appears also serves as the second and day digits of the time, and a demand switch is installed externally to operate it as a sound level meter. FIG. 3 shows a circuit of the volume control means of block 5 in FIG. The principle is to use a buzzer that has frequency characteristics as shown in FIG. 4 and whose volume varies depending on the driving frequency, and to change the volume by controlling the driving frequency using the circuit shown in FIG. The advantage of this circuit is that it allows a relatively large current to flow and eliminates the need for a volume control resistor, which is difficult to build on an LSI. Furthermore, when a volume control resistor is used, the changeover switch also becomes a switch with a relatively large current capacity for driving the buzzer, so it is not preferable to form it on an LSI because it requires a large area.

In the circuit shown in FIG. 3, the drive circuit 8 for the buzzer coil 7
Therefore, the portion for switching f ₁ to f ₆ using switches S ₆ to S ₁₁ can be formed small on an LSI without dealing with electric power. Since there is only one transistor that directly drives the buzzer in the drive circuit 8, it can be formed on an LSI, or it can be externally connected to a discrete device. For frequencies f ₁ to _{f 6} , as shown in the frequency characteristics in Figure 4, when f ₁ is selected, the volume is maximum, f ₂ → f ₃ → f ₄ → f ₅ →
f ₆ and the volume decreases in steps, in this case 6
It becomes a value selection.

As described above, according to the present invention, the buzzer can be driven at a volume that corresponds to external noise, and the buzzer volume control circuit can be configured with an extremely simple circuit by utilizing the frequency characteristics of the buzzer. be able to.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the present invention. Fig. 2 is a diagram showing an example of the display unit of the present invention. Fig. 3 is a volume control circuit, and Fig. 4 is a diagram showing the frequency characteristics of a buzzer. 1... noise level detection means, 2... analog processing means, 3... A/D conversion means, 4... digital processing means, 6... buzzer, 7... buzzer coil, 8... buzzer drive circuit.

Claims (1)

[Scope of utility model registration request] In an electronic clock that emits an alarm at a predetermined time,
A buzzer whose volume changes depending on the driving frequency, a measuring means for measuring the ambient noise level, and an A/D that converts the measurement results of the measuring means into a digital signal.
It has a volume control means for controlling the volume of the alarm sound emitted by the buzzer according to the values of the conversion means and the A/D conversion means, and the volume control means includes a changeover switch for switching signals of a plurality of different frequencies, and a buzzer. An electronic timepiece characterized by comprising a drive circuit.