CN2236706Y - Z8-Z16 channel receiver for closed-circuit TV set - Google Patents
Z8-Z16 channel receiver for closed-circuit TV set Download PDFInfo
- Publication number
- CN2236706Y CN2236706Y CN 95239047 CN95239047U CN2236706Y CN 2236706 Y CN2236706 Y CN 2236706Y CN 95239047 CN95239047 CN 95239047 CN 95239047 U CN95239047 U CN 95239047U CN 2236706 Y CN2236706 Y CN 2236706Y
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- CN
- China
- Prior art keywords
- output
- frequency
- circuit
- amplifier
- network
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
Abstract
The utility model relates to a television channel receiver. A cable television signal input socket is connected with an output plug of the receiver by a straight-pass matching circuit and a switch, and meanwhile, the input socket is connected with a high-pass matching network. Signals enter a frequency-limited amplifier by a high-frequency amplifier, and an output of the frequency-limited amplifier is connected with an input of a frequency changer by a matching absorbing network. A local oscillating circuit is also connected with the input of a frequency changer by the matching absorbing network. The output of the frequency changer is connected with the output plug, and an n-shaped attenuator is arranged between the input socket and the output plug.
Description
The utility model relates to a kind of receiver, particularly a kind of cable television channels receiver.
At present, cable TV promotes the popularization use in increasing scope, and just the problem that faces of users is that television set can not receive Z
8-Z
16The program of channel is because the high-frequency tuner of television set can not cover these channels.For addressing this problem, sell in market has television channel to augment device, and it is to control realization with the method for frequency synthesis by computer, its complex circuit, and the cost height, about 400 yuan of price is difficult for being accepted by users, is difficult to penetration and promotion.
The purpose of this utility model is exactly in order to address the above problem, and provides that a kind of circuit is simple, cost is low, the cable TV Z of dependable performance
8-Z
16The channel receiver.
Technical solution of the present utility model:
A kind of cable TV Z
8-Z
16The channel receiver, it is by straight-through match circuit (1), towering type attenuator (2), high pass matching network A
1, high-frequency amplifier A
2, frequently current limiting amplifier (3), coupling absorb network (4), local oscillation circuit (5) and frequency converter (6) composition, it is characterized in that cable TV signal input socket Z
1By straight-through match circuit (1) and K switch
1With receiver output plug Z
2Connect Z
1Meet high pass matching network A simultaneously
1, A
1Output through high-frequency amplifier A
2Be directly coupled to current limiting amplifier (3) frequently, frequently the output of current limiting amplifier (3) absorbs network (4) by coupling and links to each other with the input of frequency converter (6), local oscillation circuit (5) also absorbs network (4) by coupling and connects frequency converter (6), the output of frequency converter (6) and receiver output plug Z
2Link to each other, at Z
1With Z
2Between be connected to towering type attenuator (2).
The utility model is controlled direct circuit and Z by switch
8-Z
16Conversion between the receiving circuit, it uses simple, can guarantee that television set normally receives DS1-DS12, Z by direct circuit
4-Z
7The TV programme of channel can receive Z by receiving circuit again
8-Z
16Cable television program, its dependable performance, good stability, cheap, be easy to popularization and application.
Fig. 1 is a theory diagram of the present utility model;
Fig. 2 is an electrical schematic diagram of the present utility model.
As Fig. 1,2, straight-through match circuit of the present utility model (1) is by resistance R
1, R
10And K switch
1Constitute R
1Be connected on cable TV signal input socket Z
1Heart yearn and ground between, R
10Be connected on receiver output plug Z
2Heart yearn and ground between, K
1Be double-point double-throw switch, two contact a, b of its first cutter are connected on Z
1With Z
2Heart yearn between, two contact c, d of its second cutter are connected in the receiver power supply E supply line, and K
1A, b and c, d contact on off operating mode each other, K
1A, b contact be Z when being communicated with
1, Z
2Pass-through state.Towering type attenuator (2) is still by resistance R
1, R
10And resistance R
11Form R
11Be attempted by K switch
1On two contact a, the b of first cutter, work as K
1A, b contact when disconnecting, R
1, R
10And R
11Just form towering type attenuator, thereby with Z
1And Z
2Keep apart, its attenuation is 60db.High pass matching network A
1By capacitor C
1, CA
1With inductance L A
1Form, they are connected to a bit altogether, CA
1The other end be connected to line TV signal input socket Z
1Heart yearn, LA
1Other end ground connection, C
1The other end as high pass matching network A
1Output meet high-frequency amplifier A
2High pass matching network A
1Function two, the first effects of finishing high pass filter are arranged, its cut-off frequency is 220MHZ, second finishes input socket Z
1With high-frequency amplifier A
2The coupling of input impedance.High-frequency amplifier A
2Put pipe TA by height
1, biasing resistor R
2, load resistance R
4And inductance L A
2Form TA
1Base stage and high pass matching network A
1Output be capacitor C
1An end connect TA
1Collector electrode as high-frequency amplifier A
2Output connect current limiting amplifier (3) frequently, pass through R simultaneously
2And LA
2Connect the circuit output end of pressure-stabilizing of power supply E, because the high input impedance charcteristic of frequency current limiting amplifier (3), so A
2Amount of gain greater than 10db.Frequently current limiting amplifier (3) is by transistor T
1, resistance R
5, R
6, inductance L
1Form T
1Base stage meet high-frequency amplifier A
2Output be height put the pipe TA
1The current collection level, constitute direct-coupled circuit, T
1Collector electrode on be connected to R successively
6, L
1, R
5The load circuit of serial connection, R
5The other end link to each other T with the positive pole of power supply E
1Emitter by emitter resistance RA
1Ground connection, the output of current limiting amplifier (3) is from R frequently
6And L
1Tie point draw.Resistance R
6Work to suppress Intermodulation Interference.Coupling absorbs network (4) by resistance R
7, capacitor C
3, C
4Inductance L
2With little charged sense L
3MForm, wherein L
3M, L
2, C
4Be serially connected R
7An end and C
3An end link to each other their tie point and L
3MAn end link to each other, form T type circuit, and L
3M, L
2Outputting inductance L with local oscillation circuit (5)
6Be coupled, local oscillation circuit (5) is by resistance R
12-R
15, capacitor C
6-C
8, inductance L
5, L
6, transistor T
3The common base Colpitts oscillator of being formed, C
8Be variable capacitance, be used for changing the frequency of local oscillator.Resistance R
7The other end just be connected capacitor C with the output of frequency current limiting amplifier (3) as the input that coupling absorbs network (4)
3The other end just absorb the output of network (4) as coupling.Frequency converter (6) is by little band transistor T
2, biasing resistor R
8, load R
9With little charged sense L
4MThe common emitter microstrip line frequency converter of being formed, its input is T
2Base stage connect the output that coupling absorbs network (4), its output is T
2Collector electrode pass through capacitor C
5With receiver output plug Z
2Heart yearn link to each other.The optimum range of output frequency is 654-670MHZ.The indicating circuit of the utility model power supply and voltage stabilizing circuit are by resistance R
3, luminous tube D, filter capacitor C
2Form R with power supply E
3Be the divider resistance of luminous tube D, again with C
2Form decoupling circuit.Luminous tube D is luminous indicator tube, is again voltage-stabiliser tube, the output burning voltage.Height is put pipe TA
1The working point be that voltage stabilizing circuit is stablized because high-frequency amplifier A
2And be direct-coupled circuit between the frequency current limiting amplifier (3).So TA
1Collector stabilization current potential transistor T just
1The burning voltage of base stage, T like this
1Dc point also be stable.
The utility model when work, the input plug of cable TV signal is inserted input socket Z of the present utility model
1, with receiver output plug Z
2Insert user's television set.Receive the DS1-DS12 and the Z of cable TV as the user
4-Z
7During the program of channel, K switch
1Be in a, b contacting and position that c, d contact disconnect, be in no power supply state because power supply E of the present utility model is disconnected this moment, have only straight-through match circuit (1) connection work, the cable television program signal just directly passes through Z like this
1And K
1A, b contact and Z
2Send into television set, under this state, the resistance R in the straight-through match circuit (1)
1, R
10Equivalence is a build-out resistor, is equivalent to cable TV signal and directly sends into television set, makes television set normally receive DS wave band and Z
4-Z
7The program of channel.
When user's television set need receive cable TV Z
8-Z
16During the program of channel, only need K switch
1Be allocated to the another location, a, b contact disconnected and c, d contact are communicated with, like this resistance R
11Access circuit and and R
1, R
10Constitute towering type attenuator (2), thereby with Z of the present utility model
1And Z
2Keep apart.This moment is because K
1C, d contacting, make power supply E power supply, then receiver is started working, the cable television program signal is from Z
1Pass through CA
1, LA
2, C
1The high-frequency matching network A that forms
1, the following signal of 220MHZ is intercepted, and the above signal of 220MHZ is admitted to high-frequency amplifier A
2, A
2Signal between the 180-295MHZ is amplified, and amount of gain is 〉=10db.A
2Signal send into current limiting amplifier (3) frequently by direct coupling system.Frequently current limiting amplifier (3) is an initiative circuit of the present utility model, and it can be decayed the signal below the 180MHZ, and the signal between the 180-295MHZ is amplified, and amount of gain is 2-8db.Its principle is as follows, and the load of current limiting amplifier (3) is by R frequently
5, R
6, L
1Form, because L
1Very little in induction reactance that low-frequency range presented, and (R
6+ R
5) resistance also very little, this moment transistor T
1To not gain of low-band signal, again because R
5/ (R
6+ R
5) value in the 0.2-0.3 scope, so the signal of low-frequency range is R
6Decay, attenuation is about-15～-3db.Along with the rising of frequency, L
1To present high impedance with the resonant circuit that distributed capacitance constituted of circuit, because R
6Resistance less, so the high impedance of resonant circuit is depended in load, thereby make transistor T
1Obtain gain, amount of gain is 2-8db.
Another key technology of the present utility model is exactly by R
7, C
3, L
2, L
3M, C
4The coupling of being formed absorbs network (4), and this circuit is by R
7Be an arm, C
3Be an arm, with L
3M, L
2, C
4Be the T type matching network of an arm, this network not only can be finished the coupling between frequency current limiting amplifier (3) and the frequency converter (6), and L
3M, L
2And C
4Constitute series resonance and absorb circuit, its resonance point is 200MHZ, and this trap circuit can reach decays to the signal between the 180-220MHZ.
In sum, high pass matching network A of the present utility model
1Finish attenuation of the first kind, by frequency current limiting amplifier (3) signal below the 180MHZ is carried out second decay again, absorb network (4) by coupling again the signal between the 180-220MHZ is carried out the 3rd decay the following signal of 220MHZ.By above-mentioned technical finesse, not only overcome the interference of the strong signal of the following cable TV of 220MHZ, and overcome the strong interference of the following radiovision high field of 220MHZ.Have only to have solved these signals and enter the co-channel interference that frequency converter produces, after the problem of Intermodulation Interference and intermodulation distortion, could realize Z
8-Z
16The normal reception of channel.The oscillator signal that local oscillation circuit (5) is produced passes through L
6And L
2Coupling, absorb network (4) through coupling and together deliver to frequency converter (6) with cable TV signal.Because the utility model is by high-frequency amplifier A
2, current limiting amplifier (3) frequently, frequency converter (6) is to Z
BWave band (the overall gain amount of 223～295MHZ) signals about 25db, simultaneously, high pass matching network A
1Absorb network (4) to Z with coupling
BThe overall attenuation of band signal is about-15db, so the utility model is from the Z of frequency converter (6) output
8-Z
16The actual gain amount of channel signals is about 10db.Frequency converter (6) produced with frequency component promptly be the utility model output plug Z
2Interface frequency, its optimum range is 654-670MHZ, in the time of in the high-frequency tuner of television set being set in best interface frequency scope, promptly when 31 channels or 32 channels, can watch cable TV Z
8-Z
16In the cable television program of arbitrary channel.Z
8-Z
16The selection of channel program can be by regulating the local oscillator variable capacitance C in the circuit (5) that shakes
8Capacity finish.
Whole circuit of the present utility model is arranged in a 80 * 55mm
2Printed circuit board (PCB) on, additional two short-circuit line J
1, J
2, whole circuit are connected into unified movement.
Claims (9)
1, a kind of cable TV Z
8-Z
16The channel receiver, it is by straight-through match circuit (1), towering type attenuator (2), high pass matching network A
1, high-frequency amplifier A
2, frequently current limiting amplifier (3), coupling absorb network (4), local oscillation circuit (5) and frequency converter (6) composition, it is characterized in that cable TV signal input socket Z
1By straight-through match circuit (1) and K switch
1With receiver output plug Z
2Connect Z
1Meet high pass matching network A simultaneously
1, A
1Output through high-frequency amplifier A
2Be directly coupled to current limiting amplifier (3) frequently, frequently the output of current limiting amplifier (3) absorbs network (4) by coupling and links to each other with the defeated people of frequency converter (6), local oscillation circuit (5) also absorbs network (4) by coupling and connects frequency converter (6), the output of frequency converter (6) and receiver output plug Z
2Link to each other, at Z
1With Z
2Between be connected to towering type attenuator (2).
2, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that straight-through match circuit (1) is by resistance R
1, R
10And K switch
1Constitute R
1Be connected on cable TV signal input socket Z
1Heart yearn and ground between, R
10Be connected on receiver output plug Z
2Heart yearn and ground between, K
1Be double-point double-throw switch, two contact a, b of its first cutter are connected on Z
1With Z
2Between the heart yearn, two contact c, d of its second cutter are connected in the supply line of receiver power supply E, and K
1A, b and c, d contact on off operating mode each other, K
1A, b contact be Z when being communicated with
1, Z
2Pass-through state.
3, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that towering type attenuator (2) is still by resistance R
1, R
10And resistance R
11Form R
11Be attempted by K switch
1On two contact a, the b of first cutter, work as K
1Two contacts of a, b when disconnecting, R
1, R
10And R
11Just form towering type attenuator, with Z
1And Z
2Keep apart.
4, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that high pass matching network A
1By capacitor C
1, CA
1With inductance L A
1Form, they are connected to a bit altogether, CA
1The other end be connected to line TV signal input socket Z
1Heart yearn, LA
1Other end ground connection, C
1The other end as high pass matching network A
1Output meet high-frequency amplifier A
2
5, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that high-frequency amplifier A
2Put pipe TA by height
1, biasing resistor R
2, load resistance R
4And inductance L A
2Form TA
1Base stage and high pass matching network A
1Output be capacitor C
1An end connect TA
1Collector electrode as high-frequency amplifier A
2Output connect current limiting amplifier (3) frequently, pass through R simultaneously
2And LA
2Connect the output of the voltage stabilizing circuit of power supply E.
6, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that current limiting amplifier (3) is by transistor T frequently
1, load resistance R
5, R
6And inductance L
1Form T
1Base stage meet high-frequency amplifier A
2Output be height put the pipe TA
1Collector electrode, constitute direct-coupled circuit, T
1Collector electrode on be connected to R successively
6, L
1, R
5The load circuit of serial connection, R
5The other end and power supply E anodally link to each other T
1Emitter by emitter resistance RA
1Ground connection, the output of current limiting amplifier (3) is from R frequently
6And L
1Tie point is drawn.
7, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that coupling absorbs network (4) by resistance R
7, capacitor C
3, C
4, inductance L
2Be with little charged sense L
3MForm, wherein L
3M, L
2, C
4Be serially connected R
7An end and C
3An end link to each other their tie point and L
3MAn end link to each other, form T type circuit, and L
3M, L
2Outputting inductance L with local oscillation circuit (5)
6Be coupled R
7The other end input that absorbs network (4) as coupling be connected C with the output of frequency current limiting amplifier (3)
3The other end just absorb the output of network (4) as coupling.
8, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that frequency converter (6) is by little band transistor T
2, biasing resistor R
8, load R
9With little charged sense L
4MThe common emitter microstrip line frequency converter of being formed, its input is T
2Base stage connect the output that coupling absorbs network (4), its output is T
2Collector electrode pass through capacitor C
5With receiver output plug Z
2Heart yearn link to each other, the optimum range of output frequency is 654-670MHZ.
9, by the described cable TV Z of claim 1
8-Z
16The channel receiver is characterized in that Xiang Gaofang pipe TA
1Limit amplifier tube T with frequency
1The voltage stabilizing circuit that the stable DC working point is provided is by resistance R
3, capacitor C
2, light-emitting diode D forms.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95239047 CN2236706Y (en) | 1994-08-18 | 1995-01-14 | Z8-Z16 channel receiver for closed-circuit TV set |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN94242414 | 1994-08-18 | ||
| CN94242414.X | 1994-08-18 | ||
| CN 95239047 CN2236706Y (en) | 1994-08-18 | 1995-01-14 | Z8-Z16 channel receiver for closed-circuit TV set |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2236706Y true CN2236706Y (en) | 1996-10-02 |
Family
ID=34065596
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95239047 Expired - Fee Related CN2236706Y (en) | 1994-08-18 | 1995-01-14 | Z8-Z16 channel receiver for closed-circuit TV set |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2236706Y (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1062102C (en) * | 1997-02-26 | 2001-02-14 | 王龙善 | Channel selecting editing device for television set |
-
1995
- 1995-01-14 CN CN 95239047 patent/CN2236706Y/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1062102C (en) * | 1997-02-26 | 2001-02-14 | 王龙善 | Channel selecting editing device for television set |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |