KR910005003Y1 - Apparatus for selecting broad-casting station through scanning automatically - Google Patents

Abstract

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Description

Local and seek automatic tuning

1 is a circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

100: receiving station unit 10: digital tuning unit

1: detector 2: station detector

IC ₁ : Integrated Circuit IF: Intermediate Frequency Amplifier

RF: Wireless Intermediate Amplifier IFT: Intermediate Frequency Trans

Mixer: Mixer Q ₁ : Low Switching Transistor

Q ₂ : Seek Switching Transistor SW ₁ : Button Switch for Local + Seek (Scan)

SW ₂ : Button switch for seat (scan)

According to the present invention, in a car stereo / home stereo / cassette and the like, especially when operating an automatic tuning device such as a seek and a scan, the bad reception is not tuned in. The present invention relates to a low-calk and seek (automatic) tuning device capable of simultaneously performing operations of a local button switch and a seek button switch by tuning only good broadcasts.

In the conventional automatic tuning device of the electronic tunign radio, in order to tune only a broadcast having a good reception condition during automatic tuning, a local device (called a local button switch) is operated first, and then a seek or scan device is used again. To operate only automatic tuning.

However, in the conventional automatic tuning device, the user has to operate the low button switch and the seek button or the scan button switch. There was a problem in that the reception sensitivity was lowered because it was continuously in operation, and an error occurred when the low-com button switch had to be automatically tuned in the operation state and in the case of broadcasting a weak reception state.

The present invention is intended to solve this problem. In more detail, in order to tune to a broadcast with good reception, the low-calk + seek button switch and seek can be simultaneously performed to operate the low-calk + seek button scan and the seek button switch simultaneously. Using the scan button switch transistor of the scan button switch, the digital tuning unit can perform the seek operation and at the same time, a flip-flop that drives the low-calk + scan button switch. The reception selection unit is configured so that the local operation is performed at the same time by setting, and the low frequency operation can be released by setting the flip-flop. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In order to amplify the mixed signal through the intermediate frequency transformer (IFT) and the mixer (Mix) that mixes and outputs the amplified signal and the RF to receive and amplify the signal received from the antenna (ANT) An intermediate circuit amplifier IF and an output terminal of the intermediate frequency amplifier IF are connected to an integrated circuit unit IC ₁ composed of a detector 1 and a station detector 2 for tuning only broadcasts having good reception conditions. On the base side of the station detector 2 and the low switching transistor Q ₁ , a flip-flop FF _{1 for} turning on / off the low switching transistor through resistors R ₁ , R ₄ and R ₅ , respectively. The output terminal Q and the reset R terminal are respectively connected, and a low-cal + sheet (scan) button switch is connected between the set S terminal of the flip-flop FF ₁ , the connection point A, and the input signal terminal INT. To simultaneously perform the operation of the seek button and the seek button switch Low-Cal + Sheet (Switch) Button Switch (SW ₁ ) Seek (Scan) Button Switch (SW ₂ ), Switching Transistor (Q ₂ ) for Chic (Scan), Digital Tuning Unit (10) and Resistor (R ₂ ) It is configured by connecting the receiving station unit 100.

L ₁ , L ₂ , and L ₂ are tuning coils and capacitors of the antenna, C ₁ is a coupling capacitor, R ₃ is a resistor, and OSC is a local oscillator.

Referring to the effect of the present invention configured as described above are as follows.

First, when the user “turns on” the button switch SW ₁ for the local + sheet (scan) in order to tune only to a broadcast having a good reception state, the signal (high) input to the input signal terminal INT becomes a resistor (R _2). And a high signal is applied to the base side of the switching transistor Q ₂ for driving the turn switch SW ₂ of the seek (scan) through the low-calk + seek button switch SW ₂ . The switching transistor Q ₂ is " conducted ", so the seek (scan) button switch SW ₂ is also operated (on), so that the digital tuning unit 10 receives a good reception state, but scans to tune the broadcast. It will work.

In addition, when the "high" signal is input to the set terminal S for setting the flip-flop FF ₁ through the low-cal + sheet (scan) button switch SW ₁ , the input myth is the flip-flop FF ₁ . The signal (high) set by setting at is again applied to the base side of the local switching transistor Q ₁ through the output terminal Q and the resistor R ₁ of the flip-flop FF ₁ . The local switching transistor Q ₁ is "conducted." At this time, a signal having a poor reception state among the signals received from the antenna ANT is grounded to the emitter side of the low switching transistor Q ₁ through the coupling capacitor C ₁ , so that it is tuned and amplified in the RF amplifier. The station detector 2 which tunes only good broadcasts does not operate because it is very difficult to do so.

Since the station detector 2 does not operate as described above, the digital tuning unit 10 continues to scan.

On the other hand, when a broadcast with a good reception state received from the antenna ANT is received, the received signal is inputted to the radio intermediate amplifier (RF), amplified by the radio intermediate amplifier, and then the amplified signal is input to the mixer (Mix) in the mixer. After mixing again, the mixed signal is input to the intermediate frequency amplifier IF through the intermediate frequency transformer ITF. As the input myth is amplified by the intermediate frequency amplifier (IF), the station detector (2) inputs the station detection signal to the station detection terminal (SD) of the digital tuning unit 10, and the digital tuning unit scans it. Since the operation is stopped, only the broadcast signal having a good reception state can be tuned.

On the other hand, the station sensing signal output from the station detector 2 becomes "low" at the output terminal Q of the flip-flop FF ₁ , and the low signal is connected to the low cal switching transistor Q ₁ through the resistor R ₁ . In addition to the base axis, the low-frequency switching transistor Q ₁ becomes "non-conducting" so that low-local operation can be canceled.

The present invention, which operates as described above, operates only the automatic polar pole by first turning on the low button and then turning on the seek or scan button switch in order to tune only a broadcast having a good reception state during automatic tuning. However, in the present invention, two operations can be performed simultaneously with only one low-calk + scan (scan) button switch in order to tune only to a broadcast with good reception conditions, thereby simplifying the operation and reducing the cost of parts. Since the curl operation is automatically released, not only the reception sensitivity is improved but also an error is prevented even when receiving a weak reception state.

Claims (1)

Synchronization coils L ₁ and L ₂ and condensers C ₁ and C ₂ , which tune the broadcast signal input through the antenna ANT, an amplifier RF that amplifies the tuned radio signal, and an oscillator OSC. Mixer (MIX) for mixing the signal of the signal and the amplifier (RF), the intermediate frequency transformer (IFT) for generating the intermediate frequency signal of the mixed signal and the intermediate frequency amplifier (IF) for amplifying the intermediate frequency signal, and traffic stations A low-frequency and seek (scan) automatic tuning device of a car stereo having an integrated circuit (IC ₁ ) comprising a detector (2) and a detector (1) for detecting an amplified intermediate frequency signal; A switch (SW ₁ ) for operating at a traffic broadcasting station and a traffic broadcasting station; A switching transistor (Q ₂ ) for providing a signal for broadcasting station to the digital tuner (10) when the switch (SW ₁ ) is operated; A flip-flop (FF ₁ ) which generates a high state signal when the station is tuned and is reset when a good station is tuned; Low-channel and seek (scan), characterized in that the switching transistor (Q ₁ ) for detecting only the broadcast in a good reception state by the high state signal output from the flip-flop (FF ₁ ) when the broadcasting station is tuned Automatic tuning device.