CN201113926Y - Intermediate frequency pre-amplifying circuit - Google Patents
Intermediate frequency pre-amplifying circuit Download PDFInfo
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- CN201113926Y CN201113926Y CNU2007201717106U CN200720171710U CN201113926Y CN 201113926 Y CN201113926 Y CN 201113926Y CN U2007201717106 U CNU2007201717106 U CN U2007201717106U CN 200720171710 U CN200720171710 U CN 200720171710U CN 201113926 Y CN201113926 Y CN 201113926Y
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- resistance
- intermediate frequency
- triode
- amplifying circuit
- electrically connected
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- 230000003321 amplification Effects 0.000 abstract description 6
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 6
- 238000000034 method Methods 0.000 abstract description 3
- 230000007547 defect Effects 0.000 abstract 1
- 239000003990 capacitor Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
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Abstract
The utility model relates to an intermediate frequency pre-amplifying circuit for a television, comprising a triode, wherein, in the triode, a collecting electrode biasing supply voltage is more than that of a base electrode biasing supply voltage; the intermediate frequency pre-amplifying circuit of the utility model adopts a method of separating the collecting electrode supply from the base electrode supply and making the collecting electrode supply voltage bigger than the base electrode supply voltage, together with the setup of proper parameters, so that quiescent operating points after the intermediate frequency amplification can be accurately placed in a linear amplification area so as to avoid distortion; because the collecting electrode voltage is increased, one inductance element can be saved; moreover, because the inductance element does not need to be mounted, the defect caused by a poor choice of a frequency selective network in the design can be avoided, that is, the damage of intermediate signals due to unreasonable selection of the inductance element, thereby improving the reliability of the intermediate frequency circuit.
Description
Technical field
The utility model relates to technical field of television sets, more particularly, relates to the pre-amplifying circuit of a kind of intermediate frequency.
Background technology
The method that the pre-amplifying circuit of the intermediate frequency of existing television set adopts is that the base bias power supply is identical with the collector bias power supply and its magnitude of voltage is relatively low, is generally 5V.As shown in Figure 1.
By calculating as can be known: the static working current I of transistor emitter
E={ [1/ (1+3)] * 5-0.7}/33 ≈ 16.7mA, the quiescent operation voltage U between transistor collector and emitter
CEQ=5-I
E* 33=4.45V.The i.e. Q1 point of the quiescent point of this amplifying circuit in Fig. 3, though this point also is to be positioned at the linear amplification district, but it is near the triode saturation region, intermediate-freuqncy signal be easy in the course of the work enter the saturation region sometime, cause the intermediate-freuqncy signal saturation distortion, cause TV images adjacent channel to occur and disturb and the selectivity variation.
And in the prior art, in order to make U
CEQEnough big, collector electrode place must have an inductance element and R
CParallel connection, as shown in Figure 1, inductance L 102 is in parallel with resistance R 110.This inductance element plays resistance and exchanges perfectly straight stream.If inductance L 102, U are not installed
CEQ=5-I
E* (33+470) ≈-3.4V is negative voltage, then the amplifying circuit cisco unity malfunction.And because intermediate-freuqncy signal will be through herein, the selection of inductance need be considered the selecting frequency characteristic of a precision, if select badly, perhaps device wears out through working long hours and makes precision accurate inadequately, can cause the frequency-selecting error, intermediate-freuqncy signal is damaged, and the reliability of television set is reduced.
The utility model content
The technical problems to be solved in the utility model is, occurs the intermediate-freuqncy signal saturation distortion easily at the pre-amplifying circuit of above-mentioned existing intermediate frequency, and reliability is subject to the shortcoming of inductance choosing value influence, provides the high intermediate frequency of a kind of reliability pre-amplifying circuit.
The technical scheme that the utility model solves the problems of the technologies described above is, provides a kind of intermediate frequency pre-amplifying circuit, comprises a triode, and the collector bias supply voltage of described triode is greater than the base bias supply voltage.
In the pre-amplifying circuit of described intermediate frequency described in the utility model, described collector bias supply voltage is 12 volts of direct currents, and described base bias supply voltage is 5 volts of direct currents.
In the pre-amplifying circuit of intermediate frequency described in the utility model, described collector bias power supply only is connected to the collector electrode of triode by a resistance.
In the pre-amplifying circuit of intermediate frequency described in the utility model, also comprise three electric capacity and five resistance, wherein, frequency input terminal in one termination of first electric capacity, the other end is electrically connected to the base stage of described triode, the base stage while and first resistance of triode, second resistance, one end of second electric capacity is electrically connected, the other end ground connection of first resistance, the other end of second resistance is electrically connected to 5 volts of DC power supply, the other end of second electric capacity is electrically connected to an end of the 3rd resistance, the other end of the 3rd resistance is electrically connected to the collector electrode of triode, the collector electrode of triode is electrically connected with an end of the 4th resistance and the 3rd electric capacity simultaneously, and the other end of the 4th resistance is electrically connected to 12 volts of DC power supply, and the other end of the 3rd electric capacity is as medium frequency output end, the emitter of triode is electrically connected to an end of the 5th resistance, and the other end of the 5th resistance is connected to ground.
The pre-amplifying circuit of a kind of intermediate frequency of the utility model, adopt base supply to separate, and make the collector supply voltage method bigger, add the suitable parameters configuration than base voltage with collector supply, the quiescent point that can make the intermediate frequency amplification is avoided distortion accurately in linear amplification region.Because the raising of collector voltage can be saved an inductance element.In addition because inductance is not installed can avoid in the design because selecting frequency characteristic design shortcoming, promptly inductance element is selected unreasonablely or aging to cause accuracy error and cause intermediate-freuqncy signal is caused damage, has strengthened the reliability of intermediate-frequency circuit.
Description of drawings
The utility model is described in further detail below in conjunction with drawings and Examples, in the accompanying drawing:
Fig. 1 is the circuit diagram of the pre-amplifying circuit of intermediate frequency of prior art;
Fig. 2 is the circuit diagram of the pre-amplifying circuit of a kind of intermediate frequency of the utility model.
Fig. 3 is the comparison diagram of the quiescent point of the utility model and prior art.
Embodiment
As shown in Figure 2, it is the circuit diagram of the pre-amplifying circuit of a kind of intermediate frequency of the utility model, frequency input terminal in one termination of capacitor C 102, the other end is electrically connected to the base stage of triode V103, the base stage while and the resistance R 106 of triode, resistance R 107, one end of capacitor C 104 is electrically connected, the other end ground connection of resistance R 106, the other end of resistance R 107 is electrically connected to the 5V power supply, the other end of capacitor C 104 is electrically connected to an end of resistance R 108, the other end of resistance R 108 is electrically connected to the collector electrode of triode V103, the collector electrode of triode V103 is electrically connected with an end of resistance R 110 and capacitor C 103 simultaneously, the other end of resistance R 110 is electrically connected to the 12V power supply, the other end of capacitor C 103 is as medium frequency output end, and the emitter of triode V103 is electrically connected to an end of resistance R 109, and the other end of resistance R 109 is connected to ground.
In the pre-amplifying circuit of this intermediate frequency, base supply and collector supply separate, and base supply is direct current 5V, and collector supply is direct current 12V.Guaranteeing by strengthening collector voltage, to improve U under the base current situation identical with prior art
CEQVoltage.
By calculating as can be known: the static working current I of transistor emitter
E={ [1/ (1+3)] * 5-0.7}/33 ≈ 16.7mA, the quiescent operation voltage U between transistor collector and emitter
CEQ=12-I
E* (270+33) ≈ 6.94V.
In the utility model, electric current I
EValue identical with electric current of the prior art, but voltage U
CEQThan voltage height in the prior art, make the quiescent point of the pre-amplifying circuit of intermediate frequency be in the centre in linear amplification district, the Q2 place as Fig. 3 has so farthest avoided saturation distortion and cutoff distortion.
In the utility model,, inductance element can be installed because collector voltage is brought up to 12V.
The above; it only is the preferable embodiment of the utility model; but protection range of the present utility model is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the variation that can expect easily or replacement all should be encompassed within the protection range of the present utility model.Therefore, protection range of the present utility model should be as the criterion with the protection range of claim.
Claims (4)
1, the pre-amplifying circuit of a kind of intermediate frequency comprises a triode, it is characterized in that, the collector bias supply voltage of described triode is greater than the base bias supply voltage.
2, the pre-amplifying circuit of intermediate frequency as claimed in claim 1 is characterized in that, described collector bias supply voltage is 12 volts of direct currents, and described base bias supply voltage is 5 volts of direct currents.
3, the pre-amplifying circuit of intermediate frequency as claimed in claim 1 is characterized in that, described collector bias power supply only is connected to the collector electrode of triode by a resistance.
4, the pre-amplifying circuit of intermediate frequency as claimed in claim 1, it is characterized in that, also comprise three electric capacity and five resistance, wherein, frequency input terminal in one termination of first electric capacity, the other end is electrically connected to the base stage of described triode, the base stage while and first resistance of triode, second resistance, one end of second electric capacity is electrically connected, the other end ground connection of first resistance, the other end of second resistance is electrically connected to 5 volts of DC power supply, the other end of second electric capacity is electrically connected to an end of the 3rd resistance, the other end of the 3rd resistance is electrically connected to the collector electrode of triode, the collector electrode of triode is electrically connected with an end of the 4th resistance and the 3rd electric capacity simultaneously, the other end of the 4th resistance is electrically connected to 12 volts of DC power supply, the other end of the 3rd electric capacity is as medium frequency output end, and the emitter of triode is electrically connected to an end of the 5th resistance, and the other end of the 5th resistance is connected to ground.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201717106U CN201113926Y (en) | 2007-09-05 | 2007-09-05 | Intermediate frequency pre-amplifying circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2007201717106U CN201113926Y (en) | 2007-09-05 | 2007-09-05 | Intermediate frequency pre-amplifying circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201113926Y true CN201113926Y (en) | 2008-09-10 |
Family
ID=39965674
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2007201717106U Expired - Fee Related CN201113926Y (en) | 2007-09-05 | 2007-09-05 | Intermediate frequency pre-amplifying circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201113926Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101957599A (en) * | 2010-10-15 | 2011-01-26 | 北京联合大学生物化学工程学院 | Single-stage amplifying circuit with automatically adjustable quiescent point |
| CN102033500A (en) * | 2010-10-15 | 2011-04-27 | 北京联合大学生物化学工程学院 | Emitter follower circuit capable of automatically regulating quiescent operation point |
-
2007
- 2007-09-05 CN CNU2007201717106U patent/CN201113926Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101957599A (en) * | 2010-10-15 | 2011-01-26 | 北京联合大学生物化学工程学院 | Single-stage amplifying circuit with automatically adjustable quiescent point |
| CN102033500A (en) * | 2010-10-15 | 2011-04-27 | 北京联合大学生物化学工程学院 | Emitter follower circuit capable of automatically regulating quiescent operation point |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Dongguan Konka Electronics Co., Ltd. Assignor: Konka Group Co., Ltd. Contract record no.: 2010440000374 Denomination of utility model: Intermediate frequency pre-amplifying circuit Granted publication date: 20080910 License type: Exclusive License Record date: 20100412 |
|
| EC01 | Cancellation of recordation of patent licensing contract |
Assignee: Dongguan Konka Electronics Co., Ltd. Assignor: Konka Group Co., Ltd. Contract record no.: 2010440000374 Date of cancellation: 20100517 |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20080910 Termination date: 20130905 |
|
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Dongguan Konka Electronics Co., Ltd. Assignor: Konka Group Co., Ltd. Contract record no.: 2010440000591 Denomination of utility model: Intermediate frequency pre-amplifying circuit Granted publication date: 20080910 License type: Exclusive License Record date: 20100602 |
|
| LICC | Enforcement, change and cancellation of record of contracts on the licence for exploitation of a patent or utility model |