JPH0420164A - Notice controller - Google Patents

Abstract

PURPOSE:To prevent production of noise sound from a speaker at blink state of a light emitting element by providing a D/A converter having plural bit inputs and setting an output voltage in multi-stage and varying gradually the voltage in multi-stage at a change in the voltage of a display control signal. CONSTITUTION:A D/A converter 3 having 8-bit inputs is provided to a pre-stage of an amplifier 2. Thus, as an output change, a change in 64 stages per one state is given, and the voltage is gradually changed in multi-stage at a voltage change point of a display control signal thereby smoothing a smooth voltage change. Then a voice signal is inputted through a switch 4 comprising a transistor Qo and the amplified output by an amplifier 5 is superimposed on a display control signal. Thus, production of noise sound at blink of the light emitting element is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to an alarm system that superimposes an audio signal on a display control signal consisting of a DC voltage signal and sends it out to perform display switching control and alarm sound control of an alarm device. This relates to a control device.

[Prior Art 1] An example of a conventional device equipped with this type of notification control device is a household simple exchange device. As shown in Fig. 4, this household simple switching device consists of a switching device body A connected to a telephone office via an outside line 11, and an extension line It2 as a communication line and an extension line V as a signal transmission line to this switching device body A. Control #i1. Connected with a commercially available phone! ! Consists of a telephone outlet B to which B is detachably connected, and an external #[l,
By switching and forming a communication path between H1t and flit2, it is possible to make external and internal calls using telephone B.

In this type of household simple switching device, a display control signal and an audio signal are sent from the main body of the switching device A through a control line 13 consisting of two signal lines, and a speaker SP provided in a telephone outlet (B) sends an extension call. In addition to sounding a notification sound such as a doorbell call, the light-emitting display elements La and Lb of the telephone socket (B) are controlled to perform operation display.

In the unit, the display control signal is a voltage signal, and the audio signal is sent out superimposed on the display control signal.1 For example, the light emitting display elements La and Lb are controlled as shown in the following display.

[Problems to be Solved by the Invention] By the way, when the display function of the telephone outlet B is increased without increasing the number of light emitting display elements Lm and Lb in this type of simple telephone switching device, it is possible to increase the display function of the telephone outlet B without increasing the number of light emitting display elements Lm and Lb.
For example, when turning on and off the red light emitting display element La, the voltage of the display control signal is changed from IOV to 15V and 15V as shown in FIG.
→ Just switch to IOV.

However, when the voltage of the display control signal is switched in this manner, there is a problem in that a popping noise is generated from the speaker SP of the telephone outlet B.

Therefore, it is possible to insert a capacitor in order to slow down the rise of the display control signal, but the problem is that the display control signal waveform in this case becomes as shown in Figure 8, and it is not possible to obtain much improvement. Ta.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide an information control device that does not generate any abnormal noise even when the light emitting display element is turned off. It is in.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes an A/A converter that has a multi-bit input and can set the output voltage in multiple stages, and adjusts the voltage at the voltage change point of the display control signal. It is designed to gradually change in multiple stages.

[Effect 1] As described above, the present invention allows the output change to be set in multiple stages.
By using a /A converter, voltage changes are smoothed and noise is less likely to be generated from the speaker.

[Example] An embodiment of the present invention is shown in FIGS. 1 to 3.

In the following description, the notification control device of this embodiment will be explained in comparison with a conventional circuit. As shown in FIG. 5, the display control circuit 1 of the conventional notification control device sets one of four outputs from a CPU (not shown) that controls the operation of the exchange device main body A to a low level. bias voltage 5
V was divided into voltages, and the output thereof was DC amplified by an amplifier 2 and outputted to a control line l. Therefore, the only improvement that could be made was to insert a capacitor to slow down the rise of the output. However, in this embodiment, as shown in FIG. 1, a D/A converter 3 having an 8-bit input is provided before the amplifier 2, so the output can be changed in 64 steps per state. Therefore, at the voltage change point of the display control signal, the voltage can be gradually changed in multiple steps, and as shown in FIG. 2, the voltage change can be made smooth, making it difficult to generate noise from the speaker.

Here, the audio signal is inputted from an IC for generating a melody sound included in the main body A of the exchange device through a switch 4 made up of a transistor Q0, and the amplified output from the 7-channel amplifier 5 is superimposed on the display control signal. ing. In addition,
The switch 4 is controlled by the CPU.

The internal circuit of telephone outlet) B has the configuration shown in Figure 3, with a capacitor C inserted in series with the speaker SP.
1 to extract the audio signal, and Zener diode ZD, ~
The output of the voltage detection circuit 6 configured by combining ZD3 and transistor QQ is used to detect the respective light emitting display elements La,
Controls the lighting of Lb.

[Effect of the Invention 1] As described above, the present invention has a multi-bit input and is capable of setting the output voltage in multiple steps. Since it is designed to vary, the voltage change is smooth,
This makes it difficult to generate noise from the speakers.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an alarm control device according to an embodiment of the present invention, Fig. 2 is an output waveform diagram of the same as above, Fig. 3 is a circuit diagram of a telephone outlet as an alarm, and Fig. 4 is a simple household replacement. System configuration diagram of the device, Figure 5 is a circuit diagram of a conventional notification control device,
FIG. 6 is an explanatory diagram of the display operation, FIG. 7 is an output waveform diagram of the display control signal same as above, and FIG. 8 is an output waveform diagram of the display control signal ffi when the rise is blunted by a capacitor. 1 is a display control circuit, and 3 is a D/A converter. Agent Patent Attorney Ishi 1) Chief 7116

Claims (1)

[Claims] (1) In addition to displaying operation information using a light emitting element, an audio signal is superimposed on a display control signal consisting of a DC voltage signal and sent to an alarm device that emits an alarm sound from a speaker to switch the voltage value of the display control signal. An announcement control device that performs display switching control and emits various notification tones from a speaker by using different audio signals. An information control device characterized in that the voltage is gradually changed in multiple stages at a voltage change point of a display control signal.