CN1004783B - Antenna input circuit for receiver - Google Patents
Antenna input circuit for receiver Download PDFInfo
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- CN1004783B CN1004783B CN85107775.7A CN85107775A CN1004783B CN 1004783 B CN1004783 B CN 1004783B CN 85107775 A CN85107775 A CN 85107775A CN 1004783 B CN1004783 B CN 1004783B
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- Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Abstract
To prevent an insulating resistance value from decreasing to a dangerous value by predicting a time until the decrease in the insulating resistance arrives at the dangerous value, and presuming the rising time of a space heater to start the operation of a heater.In an insulating resistance recovery unit having an insulating resistance measuring unit for measuring the insulating resistance of a rotary electric machine 1 and a space heater 3 for drying the machine 1, time (t) until the insulating resistance value arrives at a limited value R0 on the basis of the measured value of the measuring unit is predicted. When the time (t) becomes equal to the predetermined time T from the start of the operation of the heater 3 to the start of the recovery in the insulating resistance value, the heater 3 is started. Thus, the insulating resistance value does not decrease to the value R0.
Description
The present invention is the antenna input circuit of relevant receiver, especially about the improvement problem of the receiver antenna input circuit that adopts loop aerial.
Compare with the receiver of the sort of employing ferrite bar antenna in the past, this equipment can be simplified tracking, reduce the cost of antenna itself, therefore in recent years, deliver as " the open communique of the practical new case of Japan " 151041/1982 and " the open communique of Japan's special permission " 1335/1983 are disclosed, released the receiver of employing Low ESR loop aerial.
In the receiver antenna input circuit that adopts this Low ESR loop aerial, each wave band according to medium wave, long wave etc. is provided with several corresponding tuning circuits.When wave band is changed, control the switching circuit that constitutes by elements such as transistors, the signal transmission line of conversion from the loop aerial to the tuning circuit, and the signal that loop aerial is responded to put on and the corresponding tuning circuit of selected wave band, so just can choose needed frequency.
Adopt the receiver antenna input circuit of this loop aerial to have some problems, more as number of components, control the switching circuit that switching transistor, the switch of each wave band antenna lotus root zygonema circle one end ground connection are controlled the switching diode of the signal transmission line between each wave band antenna lotus root zygonema circle and high-frequency amplifier circuit and made these switch elements actions selectively such as switching transistor, the switch of the aerial coupling coil one end ground connection that is used for making each wave band, circuit structure complexity in addition, manufacturing cost is also high.
Characteristics of the present invention are summarized as follows: loop aerial has the 1st and the 2nd end, the 1st input coil is connected with the 1st end of above-mentioned loop aerial, the 2nd input coil is connected with the 2nd end of above-mentioned loop aerial, the 1st antenna tuning circuit is connected with above-mentioned the 1st input coil, and the 2nd antenna tuning circuit is connected with above-mentioned the 2nd input coil; In receiver antenna input circuit with these loop aerials, the 1st input coil, the 2nd input coil, the 1st antenna tuning circuit and the 2nd antenna tuning circuit, according to the wave band conversion, make above-mentioned the 1st end or the 2nd end ground connection of above-mentioned loop aerial selectively.In above-mentioned the 1st input coil or the 2nd input coil, make the pairing input coil short circuit in the above-mentioned end that is grounded, and in above-mentioned the 1st antenna tuning circuit or the 2nd antenna tuning circuit, owing to adopt switching circuit, and make with the corresponding antenna tuning circuit of above-mentioned short circuit input coil inoperative.
According to other aspects of the invention, contain 1 switch element that is used for changing in the switching circuit, its effect is the direct ground connection in the 1st end or the 2nd end that conversion makes above-mentioned loop aerial according to wave band.
According to other aspects of the invention, switching circuit also contains 1 switch element, and its effect is that conversion makes above-mentioned the 1st input coil or the 2nd input coil short circuit selectively according to wave band.Therefore make the 1st end or the 2nd end ground connection of loop aerial indirectly.
According to other aspects of the invention, contain have two terminals and be connected the 1st antenna tuning circuit and the 2nd antenna tuning circuit between variable-capacitance element.Switching circuit is changed according to wave band, makes an end or the other end ground connection of variable capacitance directly or indirectly, thereby makes the 1st antenna tuning circuit or the action of the 2nd antenna tuning circuit selectively.
According to other aspects of the invention, contain 1 two terminals are arranged and be connected the 1st antenna tuning circuit and the 2nd antenna tuning circuit between variable-capacitance element.Switching circuit is made of 2 switch elements, and the effect of 1 switch element is according to wave band conversion, is used for short circuit the 1st input coil, and makes an end ground connection of the variable-capacitance element that the 1st antenna tuning circuit connects; The effect of 1 switch element is according to the wave band conversion in addition, makes the input side or the outlet side ground connection of the 2nd input coil.
Therefore, main purpose of the present invention provides an antenna input circuit that can reduce number of elements, simplify the receiver of circuit structure.
Second purpose of the present invention provides one can prevent non-receiver side input aerial in advance, disturbs the receiver antenna input circuit of receiver side input aerial.
The 3rd purpose of the present invention provide one can reduce medium wave with the stray capacitance of tuning circuit to finish the receiver antenna input circuit of accurate tuning action.
Major advantage of the present invention is only to use the input aerial of a switching circuit with regard to energy converting antenna and the non-receiver side of short circuit.
Another advantage of the present invention is to adopt the switching circuit that makes the short circuit of non-receiver side input coil according to wave band conversion, an end or other end ground connection with variable-capacitance element, therefore selectively variable-capacitance element is connected with antenna tuning circuit, and can carries out the tuner operation of each wave band by unique variable-capacitance element.
These contents of the present invention and purpose, feature, situation, advantage, in conjunction with the adjunct circuit figure of back, it is as follows to be elaborated:
The simple declaration of circuit diagram:
The 1st figure is the circuit diagram of expression the present invention the 1st embodiment.
The 2nd figure is the circuit diagram of expression the present invention the 2nd embodiment.
The 3rd figure is the circuit diagram that expression changes the 1st figure embodiment.
The 4th figure is the circuit diagram of expression the present invention the 3rd embodiment.
The 5th figure is the circuit diagram of expression the present invention the 4th embodiment.
Circuit shown in the 6th figure is a kind of conversion of the 5th figure illustrated embodiment.
The explanation of most preferred embodiment:
The 1st figure is the circuit diagram of expression the present invention the 1st embodiment.At first with reference to the 1st figure, the formation of the 1st embodiment of the present invention is illustrated.In the 1st figure, an end (X) of loop aerial 1 is connected with input coil 2 with medium wave (MW), and the other end (Y) is connected with input coil 3 with long wave (LW).Input coil 2 and 3 is made of aerial coil 2a, 3a, syntonizing coil 2b, 3b and base winding 2c, 3c respectively.The 1st trimmer capacitor 4 is connected in parallel with syntonizing coil 2b, and the 2nd trimmer capacitor 5 is connected in parallel with syntonizing coil 3b.Base winding 2c and 3c be connected in series and do not have diagram with high-frequency amplifier circuit RF(by capacitor 6) be connected.In addition, between the two ends of loop aerial 1 (X), (Y), connect 1 switch 7 with band switch (do not have diagram) interlock, the long wave side point LW of this switch 7 is connected on the end (X) of loop aerial 1, medium wave side point (MW) is connected on the other end (Y) of loop aerial 1, and shared end points COM ground connection.In addition, between the syntonizing coil 3b of the syntonizing coil 2b of input coil 2 and input coil 3,1 switch 8 with band switch (not having diagram) interlock is set equally.The long wave side point LW of this switch 8 is connected on long wave with on the syntonizing coil 3b of input coil 3, and medium wave side point MW is connected on medium wave with on the syntonizing coil 2b of input coil 2, and shared end points COM is connected in tuning with on the variable capacitor 9.
The action of the 1st embodiment of explanation the 1st the present invention who illustrates now.At first, when medium wave receives, band switch (not having diagram) is converted to medium wave one side.Like this, switch 7 and 8 respectively with this band switch interlock, and be transformed on the MW end.Its result, the other end of loop aerial 1 (Y) is through switch 7 ground connection, and therefore, long wave uses the aerial coil 3a of input coil 3 by short circuit.On the other hand, variable capacitor 9, by switch 8, the parallel circuits of forming with the syntonizing coil 2b and the 1st trimmer capacitor 4 of input coil 2 with medium wave is connected in parallel, and constitutes the antenna tuning circuit to medium wave.
Therefore, the signal responded to of loop aerial 1 imposes on the aerial coil 2a of medium wave with input coil 2.According to selecting needed frequency with the antenna tuning circuit that syntonizing coil 2b, the 1st trimmer capacitor 4 and the variable capacitor 9 of input coil 2 constitutes, be sent to high-frequency amplifier circuit RF from base winding 2c through capacitor 6 then by medium wave.
In addition, when long wave receives, convert band switch (not having diagram) to long wave one side.Like this, switch 7 and 8 respectively with this band switch interlock, and convert LW end to.Its result, an end (X) of loop aerial 1 is by switch 7 ground connection, so medium wave uses the aerial coil 2a of input coil 2 by short circuit.In addition, variable capacitor 9 is connected in parallel on the parallel circuits that long wave constitutes with the syntonizing coil 3b of input coil 3 and the 2nd trimmer capacitor 5 by switch 8, and forms the antenna tuning circuit to long wave.
Therefore, the signal that loop aerial 1 is responded to imposes on long wave with on the aerial coil 3a of input coil 3, select required frequency by long wave with the antenna tuning circuit that syntonizing coil 3b, the 2nd trimmer capacitor and the variable capacitor 9 of input coil 3 constituted, give high-frequency amplifier circuit RF from base winding 3c through base winding 2c and capacitor 9 then.
As mentioned above, the 1st embodiment according to the present invention with the input aerial of 1 switch 7 with regard to energy converting antenna and the non-receiver side of short circuit, therefore makes circuit structure simple.And input coil that can also the non-receiver side of short circuit, so can prevent the antenna of the antenna interference receiver side of non-receiver side in advance.
The 2nd figure is the circuit diagram of expression the present invention the 2nd embodiment.The 2nd circuit that illustrates is except following problem, and is identical with the 1st circuit that illustrates.That is, long wave is with being connected with varicap 10 between the syntonizing coil 3b of input coil 3 and the syntonizing coil 2b of medium wave with input coil 2.The capability value of this varicap 10 is by the control voltage control, and control voltage is to add from capacitor 11 and resistance 12 that end points 13 is used through high frequency bypass.
The following describes the action of the 2nd the present invention who illustrates the 2nd embodiment.When medium wave receives, band switch (not having diagram) is transformed into medium wave one side.Like this, switch 7 and this band switch interlock, and convert MW terminal one side to.Its result, an end (X) of loop aerial 1 is through switch 7 ground connection, and therefore, long wave uses the aerial coil 3a of input coil 3 by short circuit.
So, be transferred into the aerial coil 2a of medium wave with input coil 2 by the signal of loop aerial 1 induction.At this moment, because the aerial coil 3a of long wave input coil 3 is by short circuit, so the tuning circuit used of varicap 10, syntonizing coil 2b and trimmer capacitor 4 common formation medium waves, and its capability value is changed by the control voltage that terminal 13 adds.
Thereby, select required frequency with medium wave with tuning circuit after, deliver to the signal of medium wave with the aerial coil 2a of input coil 2, imposing on high-frequency amplifier circuit RF(from base winding 2c through base winding 3c does not have diagram).
In addition, when long wave receives, convert band switch (not having diagram) to long wave one side.Like this, switch 7 and this band switch interlock, and be converted to LW and hold a side.Its result, the other end of loop aerial 1 (Y) therefore makes the aerial coil 2a short circuit of medium wave with input coil 2 through switch 7 ground connection.
So the signal of loop aerial 1 induction is transferred to the aerial coil 3a of long wave with input coil 3.At this moment and since medium wave with the aerial coil 2a of input coil 2 by short circuit, so varicap 10, syntonizing coil 3b and trimmer capacitor 5 constitute the long wave tuning circuit together, the control voltage that applies by terminal 13 changes its capability value.
Yet, be transferred to the signal of long wave with the aerial coil 3a of input coil 3, after long wave was selected required frequency with tuning circuit, from base winding 3c, being applied in to high-frequency amplifier circuit RF(did not have diagram).
As described above, the 2nd embodiment according to the present invention by 1 variable-capacitance element 10, just can carry out the tuner operation of several wave bands, therefore makes circuit structure become simple.
The 3rd figure is the circuit diagram of expression conversion example,, in the 1st embodiment that the 1st illustrates, constitutes switching circuit with thyristor that is.In the 3rd figure, transistor 16 is in parallel with input coil 14 with long wave, and transistor 17 is in parallel with input coil 15 with medium wave.When medium wave receives, high level signal is delivered to terminal 21, so transistor 16 conductings, long wave uses input coil 14 by short circuit.Its result makes an end (X) of loop aerial 1 indirect earthed, and is converted into the medium wave antenna.In addition, when long wave receives, to terminal 22 transmission high level signals, so transistor 17 conductings, medium wave uses input coil 15 by short circuit.Its result, the other end of loop aerial 1 (Y) is by indirect earthed, and is converted into the long wave antenna.The tuning circuit corresponding with each input coil comprises varicap 18,19, and the capability value of varicap 18 and 19 is controlled by the control voltage that is applied on the terminal 20.
The 4th figure is the circuit diagram of expression the present invention the 3rd embodiment.The formation of the 4th the present invention who illustrates the 3rd embodiment at first is described.In the 4th figure, an end (X) of loop aerial 1 is connected on medium wave (MW) with on the Low ESR tap 23c of input coil 23, and the other end (Y) is connected on long wave (LW) with on the Low ESR tap 24c of input coil 24.And then trimmer 25 is in parallel with the primary side coil 23a of input coil 23 with medium wave, and trimmer 26 is in parallel with the primary side coil 24a of input coil 24 with long wave.In addition, medium wave is connected on the collector electrode of switching transistor 29 with the primary side coil 23a of input coil 23, and the grounded emitter of switching transistor 29.Simultaneously, the base stage of switching transistor 29 is connected with terminal 31 by resistance 30.For this terminal 31, when long wave receives, apply high level signal (voltage); When medium wave receives, apply low level signal (voltage), in addition, long wave is connected on the collector electrode of switching transistor 32 grounded emitter of switching transistor 32 with the primary side coil 24a of input coil 24.And then the base stage of switching transistor 32 is connected with terminal 35 through resistance 34.When long wave receives, this terminal 35 is applied low level signal (voltage), when medium wave receives, apply high level signal.Between the collector electrode of the collector electrode of switching transistor 29 and switching transistor 32, the varicap 27 of the tuning usefulness of connecting and bolcking condenser 33.The capability value of this varicap 27 changes according to the control voltage that is added on the terminal 28.
The below action of explanation the 4th the present invention who illustrates the 3rd embodiment.When medium wave receives, band switch (not having diagram) is transformed into medium wave one side.Thereupon, low level signal is imposed on terminal 31, high level signal imposes on terminal 35.Therefore switching transistor 32 conductings, long wave use the primary side coil 24a of input coil 24 by short circuit.Consequently, (Y) is indirect earthed in the end of loop aerial 1, and loop aerial 1 is converted into the medium wave antenna.In addition, an end ground connection of capacitor 33 so varicap 27 is connected with input coil 23 with medium wave, and constitutes the tuning circuit that medium wave is used with primary side coil 23a, trimmer capacitor 25 together.
Therefore, when medium wave received, the signal of being responded to by loop aerial 1 was added to medium wave input coil 23 outward.Select required receive frequency by the medium wave that primary side coil 23a, trimmer capacitor 25 and varicap 27 are constituted with tuning circuit, afterwards, from the secondary coil 23b of medium wave with input coil 23, signal is transferred to high-frequency amplifier circuit RF(does not have diagram).
In addition, when long wave receives, band switch (not having diagram) is transformed into long wave one side.Thereupon, high level signal is added to terminal 31, low level signal adds to terminal 35.Like this, switching transistor 29 is switched on, and medium wave uses the primary side coil 23a of input coil 23 by short circuit.Its result, (X) is indirect earthed in the end of loop aerial, and loop aerial 1 is switched to long wave with on the antenna.Like this, because the plus earth of varicap 27, so varicap 27 is connected long wave with on the input coil 24, and constitutes the tuning circuit that long wave is used with primary side coil 24a, trimmer capacitor 26,
So, when long wave receives, the signal that loop aerial is responded to is applied in to long wave input coil 24, and use the long wave of forming by primary side coil 24a, trimmer capacitor 26 and varicap 27 to select needed receive frequency with tuning circuit, with the secondary coil 24b coils 23b of input coil 24 signal is delivered to high-frequency amplifier circuit RF(from long wave then and does not have diagram).
As implied above, the 3rd embodiment according to the present invention, its structure is to adopt the switching circuit of the input coil short circuit that makes non-receiver side, selectively variable-capacitance element is connected on the input coil of receiver side, therefore just can carry out the tuner operation of each wave band with 1 variable-capacitance element, and circuit structure is simplified.
In addition, among the 4th embodiment that illustrates, when medium wave receives, the capacitance between the collector-base of switching transistor 29, and the capacitance between collector electrode-emitter is medium wave with the stray capacitance of tuning circuit, probably can disturb tuning action.
The 5th figure is the circuit diagram of expression the present invention the 4th embodiment, is in order to solve above-mentioned stray capacitance problem.The structure of the 5th the present invention who illustrates the 4th embodiment at first is described.In the 5th figure, an end (X) of loop aerial 1 is connected with the Low ESR tap 36c of long wave (LW) with input coil 36.Simultaneously, trimmer capacitor 38 is in parallel with the primary side coil 36a of input coil 36 with long wave, and trimmer capacitor 39 is in parallel with the primary side coil 37a of input coil 37 with medium wave.In addition, long wave is connected with the collector electrode of switching transistor 42 with the primary side coil 36a of input coil 36, and the grounded emitter of switching transistor 42.The base stage of switching transistor 42 is connected with terminal 44 by resistance 43.To this terminal 44, when receiving, long wave applies low level signal (voltage), when receiving, medium wave applies high level signal (voltage).On the other hand, medium wave is connected on the collector electrode of switching transistor 42 through bolcking condenser 46 and varicap 40 with the primary side coil 37a of input coil 37.The control voltage that is applied on the terminal 41 changes the capability value of this varicap 40.In addition, the end of loop aerial 1 (Y) is connected with the collector electrode of switching transistor 45 with the Low ESR tap 37c of medium wave with input coil 37, and the grounded emitter of switching transistor 45.The base stage of switching transistor 45 is connected on the terminal 48 by resistance 47.To this terminal 48, long wave applies high level signal (voltage) when receiving, and medium wave applies low level signal (voltage) when receiving.
The following describes the action of the 5th the present invention who illustrates the 4th embodiment.When medium wave receives, earlier band switch (not having diagram) is transformed into medium wave one side.Subsequently, terminal 44 is applied high level signal, terminal 48 is applied low level signal.Like this, switching transistor 42 is switched on, and long wave uses the primary side coil 36a of input coil 36 by short circuit.Its result, (X) is indirect earthed in the end of loop aerial 1, and loop aerial 1 is converted into the medium wave antenna.Because the plus earth of varicap 40, therefore, varicap 40 is connected with input coil 37 with medium wave, and constitutes the medium wave tuning circuit together with primary side coil 37a, trimmer capacitor 39.
Therefore, when medium wave receives, signal by loop aerial 1 induction is applied in to medium wave input coil 37, medium wave tuning circuit with primary side coil 37a, trimmer capacitor 39 and varicap 40 formations, after the receive frequency that select to need, signal is passed through coil 36b from medium wave with the secondary coil 37b of input coil 37 give high-frequency amplifier circuit RF(and do not have diagram).
At this moment, because switching transistor 45 is connected on the connection line of medium wave with the end (Y) of the tap 37c of input coil 37 and loop aerial 1, so, compare with the 4th figure embodiment, can obviously reduce the stray capacitance of medium wave with tuning circuit.
In addition, when long wave receives, band switch (not having diagram) is transformed into long wave one side.In view of the above, terminal 44 is applied low level signal, end points 48 is applied high level signal.So switching transistor 45 is switched on, the end of loop aerial 1 (Y) ground connection.Like this, if switching transistor 45 is switched on, then medium wave just becomes by the state of equivalent ground connection, therefore with input coil 37, varicap 40 is connected in long wave with on the input coil 36, and constitutes the long wave tuning circuits jointly with primary side input coil 36a, trimmer capacitor 38.
So, when long wave receives, by the signal of loop aerial 1 induction be added in long wave with the long wave of forming on the input coil 36 and by primary side coil 36a, trimmer capacitor 38 and varicap 40 with the required frequency of tuning circuit selection after, just signal is delivered to high-frequency amplifier circuit RF from long wave with the secondary coil 36b of input coil 36.
The 6th figure is the translation circuit figure of expression the 5th figure embodiment.In the 6th figure, the collector electrode of switching transistor 45 is connected medium wave with on the secondary coil 37b of input coil 37.When long wave receives, make switching transistor 45 conductings, and make secondary coil 37b short circuit.In this case, compare, also can obviously reduce medium wave with the stray capacitance of tuning circuit and carry out tuning accurately action with the 4th figure embodiment.
More than the invention has been described, and detailed diagram is arranged.Above-mentioned explanation just illustrates, and does not limit summary of the invention, and the claim that essence of an invention and scope are only added restriction.
Claims (3)
1, a kind of antenna input circuit of receiver, comprise loop aerial with the 1st end and the 2nd end, be connected on the 1st input coil on above-mentioned loop aerial the 1st end, be connected on the 2nd input coil of above-mentioned loop aerial the 2nd end, the 1st antenna tuning circuit that is connected with above-mentioned the 1st input coil, the 2nd antenna tuning circuit that is connected with above-mentioned the 2nd input coil, it is characterized in that: also comprise a switch, this switch in the wave band conversion simultaneously, make the 1st end or the 2nd end ground connection of above-mentioned loop aerial selectively, and make the input coil short circuit of corresponding above-mentioned earth terminal in above-mentioned the 1st input coil or the 2nd input coil, and make in above-mentioned the 1st antenna tuning circuit or the 2nd antenna tuning circuit corresponding above-mentioned antenna tuning circuit inoperative by the input coil of short circuit.
2, the antenna input circuit of receiver according to claim 1 is characterized in that: above-mentioned switch comprises switching transistor, and corresponding wave band conversion makes the 1st end of above-mentioned loop aerial or the 2nd end ground connection directly or indirectly.
3, according to the antenna input circuit of claim 1 or 2 described receivers, it is characterized in that: also comprise one one above-mentioned first antenna tuning circuit of termination and the other end connects the variable-capacitance element of above-mentioned the 2nd antenna tuning circuit, the corresponding wave band conversion of above-mentioned switch makes an end or the other end ground connection of above-mentioned variable-capacitance element, like this, after receiving above-mentioned variable-capacitance element on above-mentioned the 1st antenna tuning circuit or the 2nd antenna tuning circuit selectively, just can make above-mentioned the 1st antenna tuning circuit or the 2nd antenna tuning circuit work.
Applications Claiming Priority (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP151357/84 | 1984-10-05 | ||
| JP151357/1984 | 1984-10-05 | ||
| JP15135784U JPS6168538U (en) | 1984-10-05 | 1984-10-05 | |
| JP152503/1984 | 1984-10-09 | ||
| JP15250284U JPS6168539U (en) | 1984-10-09 | 1984-10-09 | |
| JP15250384U JPS6168540U (en) | 1984-10-09 | 1984-10-09 | |
| JP152502/1984 | 1984-10-09 | ||
| JP153872/1984 | 1984-10-11 | ||
| JP15387284U JPS6170448U (en) | 1984-10-11 | 1984-10-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN85107775A CN85107775A (en) | 1986-08-06 |
| CN1004783B true CN1004783B (en) | 1989-07-12 |
Family
ID=27473081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN85107775.7A Expired CN1004783B (en) | 1984-10-05 | 1985-10-05 | Antenna input circuit for receiver |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1004783B (en) |
-
1985
- 1985-10-05 CN CN85107775.7A patent/CN1004783B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CN85107775A (en) | 1986-08-06 |
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