KR970004659Y1 - Automatic frequency control circuit - Google Patents
Automatic frequency control circuit Download PDFInfo
- Publication number
- KR970004659Y1 KR970004659Y1 KR2019940035882U KR19940035882U KR970004659Y1 KR 970004659 Y1 KR970004659 Y1 KR 970004659Y1 KR 2019940035882 U KR2019940035882 U KR 2019940035882U KR 19940035882 U KR19940035882 U KR 19940035882U KR 970004659 Y1 KR970004659 Y1 KR 970004659Y1
- Authority
- KR
- South Korea
- Prior art keywords
- capacitor
- aft
- diode
- variable capacitance
- automatic frequency
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
- Superheterodyne Receivers (AREA)
Abstract
내용없음.None.
Description
제 1 도는 종래의 자동 주파수 조정회로도1 is a conventional automatic frequency adjustment circuit diagram
제 2 도는 본 고안의 자동 주파수 조정회로도2 is an automatic frequency adjustment circuit diagram of the present invention
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
R11, R12: 저항 VD11∼VD14: 가변용량 다이오드R 11 and R 12 : resistance VD 11 to VD 14 : variable capacitance diode
C11∼C12: 콘덴서 L11, L12: 코일C 11 to C 12 : condenser L 11 , L 12 : coil
본 고안은 튜너부의 국부발진기가 항상 일정한 주파수로 발진되게 하는 자동 주파수 조정회로(이하, 'AFT회로'라고 약칭함)에 관한 것으로 특히 UHF 밴드용 AFT회로와 VHF 밴드용 AFT회로를 분리하여 상호간에 간섭현상이 발생되지 않도록 하는 자동 주파수 조정회로에 관한 것이다.The present invention relates to an automatic frequency adjustment circuit (hereinafter, abbreviated as 'AFT circuit') that allows the local oscillator of the tuner to always oscillate at a constant frequency. In particular, the UHF band AFT circuit and the VHF band AFT circuit are separated from each other. The present invention relates to an automatic frequency adjustment circuit for preventing interference from occurring.
종래의 AFT회로는 제 1 도에 도시된 바와 같이, 입력되는 AFT 신호가 저항(R1)을 통해 가변용량 다이오드(VD11)에 인가되게 접속하고, 그 접속점을 콘덴서(C1)롤 통해 접지코일(L1)과, 직렬로 접속된 가변용량 다이오드(VD2) 및 접진 콘덴서(C2)에 접속하여 가변용량 다이오드(VD2) 및 접지 콘덴서(C2)의 접속점에 전원(B+)이 인가되게 함과 아울러 콘덴서(C1), 접지코일(L1) 및 가변용량 다이오드(VD2)에 접속점에 콘덴서(C3)(C4)의 일측단자를 접속하여 콘덴서(C3)(C4)의 타측단자에서 제1 AFT신호가 출력되게 제1 AFT조정부(1)를 구성하였다.In the conventional AFT circuit, as shown in FIG. 1, the input AFT signal is connected to the variable capacitance diode VD 11 through the resistor R1, and the connection point is connected to the ground coil through the capacitor C 1 roll. applied to (L 1) and a power source (B +) at the junction of the variable capacitance diode (VD 2) and jeopjin capacitor connected to (C 2) variable capacitance diode (VD 2) and a ground capacitor (C 2) connected in series presented hereinafter as well as a capacitor (C 1), the ground coil (L 1) and a variable capacitance diode capacitor to the connection point to the (VD 2) (C 3) capacitor (C 3) and connecting the one terminal of the (C 4) (C 4 The first AFT adjusting unit 1 is configured such that the first AFT signal is output from the other terminal.
그리고 저항(R1) 및 가변용량 다이오드(VD1)의 접속점을 콘덴서(C5)를 통해 접지코일(L2)과 직렬로 접속된 가변용량 다이오드(VD3) 및 접지 콘덴서(C6)에 접속하여 가변용량 다이오드(VD3) 및 접지 콘덴서(C6)의 접속점에 전원(B+)이 인가되게 함과 아울러 콘덴서(C5), 접지코일(L2) 및, 가변용량 다이오드(VD33)의 접속점에 콘덴서(C7)(C8)의 일측단자를 접속하여 콘덴서(C7)(C8)의 타측단자에서 제2 AFT신호가 출력되게 제2AFT조정부(2)를 구성하였다.The connection point of the resistor R 1 and the variable capacitor diode VD 1 is connected to the variable capacitor diode VD 3 and the ground capacitor C 6 connected in series with the ground coil L 2 through the capacitor C 5 . By connecting power supply B + to the connection point of the variable capacitor diode VD 3 and the ground capacitor C 6 , the capacitor C 5 , the ground coil L 2 , and the variable capacitor diode V 3 3 the connection point of the capacitor (C 7) connected to one terminal of the capacitor to (C 8) (C 7) the 2AFT adjuster (2) to be the second AFT signal is output from the other terminal of the (C 8) was constructed.
이와 같이 구성된 종래의 AFT회로는 전원(B+)이 인가되면, 인가된 전원(B+)에 의해 가변용량 다이오드(VD2)(VD3)는 일정한 용량을 가지게 되고, 입력되는 AFT신호는 저항(R1)을 통해 가변용량 다이오드(VD1)에 인가되어 가변용량 다이오드(VD1)는 입력되는 AFT신호는 레벨에 따라 용량이 가변된다.In the conventional AFT circuit configured as described above, when the power source B + is applied, the variable capacitance diode VD 2 (VD 3 ) has a constant capacity by the applied power source B +, and the input AFT signal is a resistor R 1) is applied to the variable capacitance diode (VD 1) variable-capacity diode (VD 1) through the AFT signal is inputted, the capacity is varied according to the level.
이와 같은 상태에서 제1 밴드 즉, UHF밴드에서는 가변용량 다이오드(VD1) 및 콘멘서(C1)가 동조되어 UHF밴드의 신호가 제1 AFT조정부(1)에 입력되고, 콘덴서(C3)(C4)를 통해 제1 AFT신호로 출력되어 국부발진 주파수를 조정하게 된다.In this state, in the first band, that is, the UHF band, the variable capacitance diode VD 1 and the capacitor C 1 are tuned so that a signal of the UHF band is input to the first AFT adjusting unit 1, and the capacitor C 3 is provided. Through (C 4 ) is output as the first AFT signal to adjust the local oscillation frequency.
그리고 제2 밴드 즉 VHF 멘드에서는 가변용량 다이오드(VD1) 및 콘덴서(C5)가 동조되어 VHF 밴드의 신호가 제2 AFT 조정부(2)에 입력되고, 콘덴서(C7)(C8)롤 통해 제2 AFT신호로 출력되어 국부발진 주파수를조정하게 된다.In the second band, that is, the VHF men, the variable capacitor diode VD 1 and the capacitor C 5 are tuned so that the signal of the VHF band is input to the second AFT adjusting unit 2 and the capacitor C 7 (C 8 ) rolls. Through the second AFT signal is output to adjust the local oscillation frequency.
그러나 상기와 같은 종래의 AFT회로는 제1 및 제2 AFT 조정부(1)(2)가 가변용량 다이오드(VD1)를 공용하므로 제1 AFT 조정부(1)의 동작시 콘멘서(C5)의 간섭을 받게 되고, 제2 AFT 조정부(2)의 동작시 콘덴서(C1)의 간섭을 받게 되고, 이로 인하여 국부발진기의 발진 주파수를 정확하게 조정하지 못함은 물론 온도특성이 나쁘게 되는 등의 문제점이 있었다.However, conventional AFT circuit as described above of the first and the second AFT adjusting section (1) and (2) a variable capacity diode during operation cones menseo (C 5) of the first AFT adjusting section (1), so share a (VD 1) There is a problem that the interference of the condenser (C 1 ) during the operation of the second AFT control unit 2, due to the interference does not accurately adjust the oscillation frequency of the local oscillator, as well as the temperature characteristics are bad. .
본 고안은 상기와 같은 종래의 제반 문제점들을 해결하기 위하여 고안한 것으로서 제1 및 제2 AFT 조정부를 완전히 분리 구성하여 상호간의 간섭이 발생되지 않도록 함으로써 국부발진기의 발진 주파수를 정확하게 조정하고, 온도특성을 향상시킬 수 있도록 하는 자동 주파수 조정회로를 제공하는 데 그 목적이 있는 것으로 이를 첨부된 제 2 도의 도면을 참조하여 상세히 설명한다.The present invention has been devised to solve the above-mentioned problems, and the first and second AFT adjusting parts are completely separated so that the mutual interference does not occur, thereby accurately adjusting the oscillation frequency of the local oscillator and improving the temperature characteristics. It is an object of the present invention to provide an automatic frequency adjustment circuit that can be improved, which will be described in detail with reference to the accompanying drawings of FIG.
제 2 도는 븐 고안의 자동 주파수 조정회로도로서 이에 도시된 바와 같이, 입력되는 AFT신호가 저항(R11)(R12)을 각기 통해 가변용량 다이오드(VD11)(VD12)에 인가되게 접속하고, 그 접속점을 콘덴서(C11)(C15)를 통해 접지코일(L11)(L12)과, 직렬로 접속된 가변용량 다이오드(VD12)(V13) 및 접지 콘덴서(C12)(C13)에 접속하여 가변용량 다이오드(VD12)(VD13) 및 접지 콘덴서(C12)(C13)의 접속점에 전원(B+)이 인가되게 함과 아울러 콘덴서(C11)(C15), 접지코일(L11)(L12) 및 가변용량 다이오드(VD12)(VD13)의 접속점에 콘덴서(C13, C14)(C17, C18)의 일측단자를 접속하여 콘덴서(C13, C14)(C17, C18)의 타측단자에서 제1AFT신호 및 제2 AFT신호가 각기 출력되게 구성하였다.2 is an automatic frequency adjustment circuit diagram of the invention of the present invention, as shown therein, the input AFT signal is connected to the variable capacitor diode (VD 11 ) (VD 12 ) through the resistor (R 11 ) (R12), respectively, The connection point is connected to the ground coil (L 11 ) (L 12 ) through the capacitor (C 11 ) (C 15 ), the variable capacitance diode (VD 12 ) (V 13 ) and the ground capacitor (C 12 ) (C connected in series. 13 ), the power supply (B +) is applied to the connection point of the variable capacitance diode (VD 12 ) (VD 13 ) and the ground capacitor (C 12 ) (C 13 ), and the capacitor (C 11 ) (C 15 ), ground coil (L 11) (L 12) and a variable capacitance diode (VD 12) capacitors to the connection point of the (VD 13) (C 13, C 14) a capacitor (C 13 by connecting the one terminal of the (C 17, C 18) , C 14 ) (C 17 , C 18 ) are configured to output the first and second AFT signals, respectively.
이와 같이 구성된 본 고안의 AFT회로는 전원(B+)이 인가되면, 인가된 전원(B+)에 의해 가변용량 다이오드(VD12)(VD14)는 일정한 용량을 가지게 되고, 입력되는 AFT신호는 저한(R11)(R12)을 통해 가변용량 다이오드(VD12)(VD13)에 각기 인가되어 가변용량 다이오드(VD11)(VD13)는 입력되는 AFT신호의 레벨에 따라 용량이 가변된다.In the AFT circuit of the present invention configured as described above, when the power source B + is applied, the variable capacitance diode VD 12 (VD 14 ) has a constant capacitance by the applied power source B +, and the input AFT signal is low ( R 11 ) and R 12 are respectively applied to the variable capacitance diodes VD 12 and VD 13 so that the capacitances of the variable capacitance diodes VD 11 and VD 13 vary according to the level of the input AFT signal.
그러므로 제1 밴드 즉. UHF밴드에서는 가변용량 다이오드(VD11) 및 콘덴서(C11)가 동조되어 UHF밴드의 신호가 저항(R11)을 통해 가변용량 다이오드(VD11)에 인가되고, 콘덴서(C11)롤 다시 통해 코일(L11) 및 가변용량 다이오드(VD12)에 인가된 후 콘덴서13)(C14)롤 통해 제1 AFT신호로 출력되어 UHF밴드의 국부발진기의 발진주파수롤 조정하게 된다.Hence the first band i.e. In the UHF band, the variable capacitor diode (VD 11 ) and the capacitor (C 11 ) are tuned so that the signal of the UHF band is applied to the variable capacitor diode (VD 11 ) through the resistor (R 11 ), and the capacitor (C 11 ) rolls back through. coil is first outputted to the AFT signal (11 L) and the variable capacitance diode through the condenser and then 13) (C 14) applied to the roll (VD 12) thereby adjusting the oscillation frequency of the local oscillator of the UHF band roll.
그리고 제2 밴드 즉, VHF밴드에서는 가변용량 다이오드(VD13) 및 콘덴서(C15)가 동조되어 VHF밴드의신호가 저항(R12)을 통해 가변용량 다이오드(VD13)에 인가되고, 콘덴서(C15)를 다시 통해 코일(L12) 및 가변용량 다이오드(VD14)에 인가된 후 콘덴서(C17)(C18)롤 통해 제2 AFT신호를 출력되어 VHF 밴드의 국부발진기의 발진 주파수를 조정하게 된다.In the second band, that is, the VHF band, the variable capacitor diode VD 13 and the capacitor C 15 are tuned so that a signal of the VHF band is applied to the variable capacitor diode VD 13 through the resistor R 12 . C 15 ) is applied to the coil (L 12 ) and the variable capacitance diode (VD 14 ) again, and then the second AFT signal is output through the condenser (C 17 ) (C 18 ) to adjust the oscillation frequency of the local oscillator of the VHF band. Will be adjusted.
이상에서 상세히 설명한 바와 같이 본 고안은 UHF밴드 및 VHF 밴드의 AFT회로를 각기 구성하여 상호간에 간섭을 주지 않도록 함으로써 AFT동작을 정확하게 수행하여 UHF밴드의 국부발진기와VHF밴드의 국부발진기의 발진주파수를 정확하게 조절하고, 온도특성이 향상되는 등의 효과가 있다.As described in detail above, the present invention configures the AFT circuits of the UHF band and the VHF band so as not to interfere with each other, thereby accurately performing the AFT operation so that the oscillation frequencies of the local oscillator of the UHF band and the local oscillator of the VHF band can be precisely determined. It has an effect of adjusting and improving a temperature characteristic.
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019940035882U KR970004659Y1 (en) | 1994-12-26 | 1994-12-26 | Automatic frequency control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR2019940035882U KR970004659Y1 (en) | 1994-12-26 | 1994-12-26 | Automatic frequency control circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR960025863U KR960025863U (en) | 1996-07-22 |
| KR970004659Y1 true KR970004659Y1 (en) | 1997-05-15 |
Family
ID=19402855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR2019940035882U KR970004659Y1 (en) | 1994-12-26 | 1994-12-26 | Automatic frequency control circuit |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR970004659Y1 (en) |
-
1994
- 1994-12-26 KR KR2019940035882U patent/KR970004659Y1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR960025863U (en) | 1996-07-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4089938B2 (en) | Voltage controlled oscillator | |
| US20030164743A1 (en) | Varactor folding technique for phase noise reduction in electronic oscillators | |
| KR0153379B1 (en) | Voltage control oscillator for up-down converter of digital wireless communication system | |
| US5144264A (en) | Wideband voltage controlled oscillator having open loop gain compensation | |
| US5694092A (en) | Voltage-controlled oscillator including first and second varactors having differing rates of change in capacitance value | |
| JP3522283B2 (en) | Oscillator device with variable frequency | |
| KR20000069168A (en) | Oscillator | |
| US3959728A (en) | Local oscillation circuit for tuner having reduced inter-channel deviation in AFC sensitivity | |
| EP0227402B1 (en) | Controllable oscillator | |
| KR970004659Y1 (en) | Automatic frequency control circuit | |
| KR0176631B1 (en) | Auto fine tuning circuit | |
| US4369417A (en) | Circuit for tunable radio-frequency circuits | |
| US3940714A (en) | AFC circuit with improved sensitivity | |
| JPH09284157A (en) | Tuner provided with distribution circuit | |
| US20020130735A1 (en) | Input trap circuit and image trap circuit | |
| US4564822A (en) | TV Tuner oscillator with feedback for more low frequency power | |
| JPS5827562Y2 (en) | VHF tuner | |
| JPH0218586Y2 (en) | ||
| JPH066634Y2 (en) | Tuning circuit for local oscillation | |
| KR930002851Y1 (en) | Input/output switching circuit of pll tuner | |
| JPS6360926B2 (en) | ||
| JPH042500Y2 (en) | ||
| JP3050883B2 (en) | Electronic tuner | |
| KR900010618Y1 (en) | Local oscillator output stabilizing circuit of electronic tuner | |
| KR19990009990A (en) | Oscillator circuit of tuner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E701 | Decision to grant or registration of patent right | ||
| REGI | Registration of establishment | ||
| FPAY | Annual fee payment |
Payment date: 20000417 Year of fee payment: 4 |
|
| LAPS | Lapse due to unpaid annual fee |