JPH02153656A - Telephone set ringing tone circuit - Google Patents

Abstract

PURPOSE:To freely adjust the sound volume of ringing tone even after the assembly of a telephone set ringing tone circuit is completed by installing a sound volume adjustment device which calls the telephone set ringing tone circuit and which can variably adjust the sound volume of ringing tone by means of an external operation. CONSTITUTION:The sound volume adjustment device 6 which is switched and controlled in four levels by a controller 9 is connected between a resistance 4 and a transistor 3. Transistors 7a and 7b in the sound volume adjustment device 6 are turned on and off in correspondence with the switching of four levels of a micro computer device in the controller 9, and the combination of ON/OFF comes to four kinds. The value of a base current in the transistor 3, which is decided by the rate of the resistance 4 and resistances 8a and 8b, and the sound volume of ringing tone from a buzzer 1 changes in four levels. Thus, the sound volume of ringing tone can be adjusted by designation from outside after completion of the circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telephone ringing circuit capable of adjusting the volume of the telephone ringing tone.

[Conventional technology]

FIG. 3 is a circuit diagram showing a conventional telephone ringer circuit. In the figure, 1 is a buzzer as a sounding body that produces a ringer, 2 is a protection diode for absorbing reverse voltage by the coil of the buzzer 1, and 3 is the above-mentioned protection diode. A transistor serves as a driver for turning the buzzer 1 on and off to generate sound, a resistor 4 controls the base current of the transistor 3, and an oscillator 5 serves as a driver for generating a pulse signal for turning the transistor 3 on and off.

A pulse signal generated by an oscillator 5, the operation of which will be described next, turns the transistor 3 on and off, and accordingly the voltage applied to the buzzer 1 changes, producing a ringing tone. In this case, the back electromotive force generated when the voltage difference between the buzzer 1 suddenly becomes zero is absorbed by the protection diode 2, and the transistor 3 is prevented from being destroyed.

(Problems to be Solved by the Invention) Since the conventional telephone ringer circuit is configured as described above, the volume of a sounding body such as a buzzer is determined by the power supply voltage, etc., and after the circuit is completed, instructions from the outside cannot be received. There was a problem in that the volume could not be changed by

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a telephone ringing tone circuit in which the volume of the ringing tone can be adjusted by an instruction from the outside after the circuit is completed.

[Means to solve the problem]

The telephone ringer circuit according to the present invention allows the volume of the telephone ringer to be adjusted by an externally operated volume adjustment device such as an external switch.

[Effect]

The volume adjustment device according to the present invention allows the volume of the ringing tone to be freely varied by simple operation of an external switch or the like.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 to 5 are completely the same as the above-mentioned conventional circuit, 6 is a volume adjustment device that variably adjusts the volume of the ringing tone from the buzzer 1, and 7a and 7b constitute this volume adjustment device 6. 8a and 8b are resistors for adjusting the transistors 7a and 7b, and 9 is an external switch, for example, for switching the volume in four stages. It is a control device for

Next, the operation will be explained. Between the resistor 4 and the transistor 3, there is a volume adjustment device that is switched and controlled in four stages by the control device 9! ! 6 is connected, the volume adjustment device 16 can be adjusted according to the four-stage switching operation of the external switch of the control device 9.
Transistor 7a inside.

7b is turned on and off, and there are four types of combinations of on and off. Therefore, resistor 4 and resistor 8a.

The value of the base current of the transistor 3 determined by the ratio of 8b also changes in four steps, and the volume of the ringing tone from the buzzer 1 also changes in four steps.

Note that in the above embodiment, the volume adjustment device 6 includes a transistor 7.
Although analog switches 10a and 7b are used, analog switches 10a and 10b may be provided as shown in FIG.

Further, in the above embodiment, the volume adjustment device 6 has four levels of volume switching, but of course the present invention is not limited to this.

Furthermore, the sounding body is not limited to a buzzer.

〔Effect of the invention〕

As described above, according to the present invention, the telephone ringer circuit is configured with a volume adjustment device that can variably adjust the volume of the ringer by an external operation such as an external switch, so that the volume of the ringer can be adjusted. This has the advantage that it can be freely adjusted even after the telephone ringer circuit is assembled.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a telephone ringer circuit according to an embodiment of the present invention, FIG. 2 is a modified circuit diagram of a volume adjustment device 6, and FIG.
The figure is a circuit diagram of a conventional telephone ringer circuit. 1 is a buzzer (sounding body), 3 is a transistor (driver),
5 is an oscillator (driver), 6 is a volume adjustment device, 9 is a control device, and 10a and 10b are analog switches (driver). Note that the same reference numerals in each figure indicate the same or corresponding parts. Figure 2 Patent applicant Mitsubishi Electric Corporation

Claims (1)

[Claims] A telephone set comprising: a sounding body that produces a ring tone of the telephone; a driving body that drives the sounding body to generate the sound; a volume adjustment device that adjusts the volume of the ring tone; and a control device that controls the volume adjustment device. Ringer circuit.