KR790001918Y1 - Tone-dail generator - Google Patents

Abstract

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Description

Tone Dial Generator

1 is a block diagram of the tone dial generator of the present invention.

2 is a detailed circuit diagram of FIG.

The present invention can be used in combination with an existing automatic impulse telephone, and can use both an impulse dial and a tone dial, and a telephone auxiliary device designed to use a tone dial in combination with an idle telephone. It is about.

There are two types of telephone subscriber calling methods: Impulse Dial and Tone Dial. Impulse Dial generates a designated pulse signal as a call signal by turning the dial. Instead of turning the dial, press the button to send the exchange connection signal to the specified tone. The present invention provides the function to use the tone dial for the impulse phone and is installed next to the telephone set. When using the generated signal as a subscriber call signal by acoustic coupling to the talker through a speaker or when calling a subscriber using a mobile telephone, a separately made pad (PAD) is inserted into the jack of the present invention. One end can be used as a call signal by connecting to the microphone input terminal of a wireless telephone device. Frequencies are given in Table 1.

Table 1 Signal Frequency

As shown in Table 1, when one button is pressed, one signal selected from the high frequency group and the low group frequency is synthesized and transmitted, and the signal generator is shown in Figure 1.

IC internal structure used in the present invention

1) 2 sets of frequency divider

2) 2 sets of digital counter

3) 2 sets of decoder

4) Two sets of sine wave generators

5) Comprising the main oscillator and multiple key disable circuit, the frequency divider identifies the number pressed on the key board so that the frequency oscillated from the main oscillator corresponds to the corresponding key. Frequency dividing and control of the counter circuit to make the tone signal equal to 1, the counter circuit counts the divided frequency and sends it to the decoder. The decoded signal from the decoder is sent to the sine wave generator, and the sine wave generator generates a sine wave corresponding to the signal sent from the decoder.

The frequency divider, the digital counter, and the decoder have two sets of each because the lower frequency and the higher frequency are processed separately.

The main oscillator oscillates by connecting an external crystal (X-TAL), and the Multiple Key Disable circuitry monitors which keys are pressed on the keyboard.

Using the detailed circuit diagram of the present invention, for example, the terminal of the built-in power supply is grounded and the terminal is connected to one of the terminals C ₃ and R ₄ in the emitter of the Q ₁ PNP transistor. It is connected. Q ₁ is the switching TR, and in STANDBY, the intermediate contact of R ₄ of R ₃ is assumed to be blocked when the + coin is stuck between the emitter and the base, and then the license plate is pressed. is grounded in the plates causes a voltage drop on R ₄ both ends wherein Q ₁ is the collector and the IC's are forward biased (forward bias) is an operating state after via the R ₂ a power supply voltage produced by the constant voltage by the D ₁ Q ₂ VDD Supply the voltage. At this time, logic “1” or High voltage is supplied to all buttons except IC PIN 3 and 12 terminals connected to the number plate, and only terminals corresponding to No. 1 are operated. Oscillate sine wave

In order to generate the frequency as shown in Table 1 corresponding to the number pressed on the keyboard, the oscillating output is processed in the IC internal structure. outputting a frequency (Higher frequency), and this output is balanced (bALANCE) in VR ₁ and the wake (Filtering) by R _2, C ₁ C ₂ of the collector circuit by supplying to the base of Q ₂ is Q ₂ operates the speaker and Tone signal is generated through the volume control door speaker with VR ₂ connected in series. It can be used by using wireless subscriber calling method and tone dial method by attaching jack terminal 있는 which can be connected to the output circuit to the outside, and malfunction of call signal due to excessive or weak output from jack It is supposed to adjust VR ₂ to prevent it.

The relationship between the signal frequency and IC PIN according to the button of the number board is shown in Table 2, and the generated signal is sent to the central station as a subscriber call signal through the handset of the telephone handset.

TABLE 2

Claims (1)

By the switching operation of the transistor (Q ₁₎ the zener diode (D ₁₎ to creates a constant voltage balanced by the tone signal output from the IC to the variable resistor (VR ₁₎ in to operate the transistor (Q ₂₎ transistors (Q ₂₎ Tone dial generating device, characterized in that the speaker connected to the emitter of the tone signal to convert the sound signal to a telephone call of the telephone to combine the subscriber call signal.