JPH0145248B2 - - Google Patents
Info
- Publication number
- JPH0145248B2 JPH0145248B2 JP2095580A JP2095580A JPH0145248B2 JP H0145248 B2 JPH0145248 B2 JP H0145248B2 JP 2095580 A JP2095580 A JP 2095580A JP 2095580 A JP2095580 A JP 2095580A JP H0145248 B2 JPH0145248 B2 JP H0145248B2
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- tuning
- section
- resistor
- transistor
- 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
Links
- 230000001105 regulatory effect Effects 0.000 claims description 19
- 230000033228 biological regulation Effects 0.000 claims description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000004891 communication Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J5/00—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner
- H03J5/24—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection
- H03J5/246—Discontinuous tuning; Selecting predetermined frequencies; Selecting frequency bands with or without continuous tuning in one or more of the bands, e.g. push-button tuning, turret tuner with a number of separate pretuned tuning circuits or separate tuning elements selectively brought into circuit, e.g. for waveband selection or for television channel selection using electronic means
Landscapes
- Channel Selection Circuits, Automatic Tuning Circuits (AREA)
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明はテレビジヨン受信装置に於いて、受信
可能周波数範囲を制限した選局装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a channel selection device that limits the receivable frequency range in a television receiver.
(技術背景)
一般にテレビジヨン受信装置では、選局装置中
の使用部品の誤差、経時変化、或は温度変化等に
より、受信可能な周波数の上限或は下限が大きく
変化するのを予め見越し、専らテレビジヨン放送
を確実に受信出来ることのみを主眼に置いて、受
信可能な周波数帯域(以下、スイープ範囲とい
う)を実際の放送周波数帯域(以下、有局範囲と
いう)より十分広く設計している。(Technical background) In general, television receivers are designed in advance to anticipate that the upper or lower limit of receivable frequencies will change significantly due to errors in parts used in the channel selection device, changes over time, changes in temperature, etc. The receivable frequency band (hereinafter referred to as "sweep range") is designed to be sufficiently wider than the actual broadcast frequency band (hereinafter referred to as "stationed range") with the sole focus of ensuring that television broadcasts can be received reliably.
チユーナ部に同調素子として可変容量ダイオー
ドを使用した所謂「電子同調チユーナ」に於いて
は、従来より第7図に示す如き選局装置が装備さ
れている。選局部4は、定電圧ダイオード31を
具えた電源3から供給される基準電圧Vzを分圧
して受信チヤンネル毎の同調電圧を形成する複数
の可変抵抗器6を具え、各可変抵抗器の出力端は
夫々スイツチング用ダイオード51を介して互い
に連結し、該連結点は、温度補償を施す為のトラ
ンジスター71を介してチユーナ1の同調電圧入
力端子18に接続している。 A so-called "electronic tuning tuner" using a variable capacitance diode as a tuning element in the tuner section has conventionally been equipped with a tuning device as shown in FIG. The tuning section 4 includes a plurality of variable resistors 6 that divide a reference voltage Vz supplied from a power supply 3 equipped with a constant voltage diode 31 to form a tuning voltage for each reception channel, and the output terminal of each variable resistor are connected to each other via switching diodes 51, and the connection point is connected to the tuning voltage input terminal 18 of the tuner 1 via a transistor 71 for temperature compensation.
上記選局装置に於いては、何れか1つ又は複数
の可変抵抗器6を可変範囲の全域に亘つて操作す
るスイープ動作により、同調電圧Vtが例えば
0.2V〜33±3Vの範囲で変動し、同調電圧Vtが例
えば24Vの時に有局範囲の上限、数Vの時に下限
が受信出来る様に設計している。 In the above channel selection device, the tuning voltage Vt can be adjusted, for example, by a sweep operation in which one or more variable resistors 6 are operated over the entire variable range.
It fluctuates in the range of 0.2V to 33±3V, and is designed so that the upper limit of the stationed range can be received when the tuning voltage Vt is, for example, 24V, and the lower limit can be received when it is several volts.
第6図は、横軸に同調電圧Vt、左側の2本の
縦軸に夫々VHFハイバンド及びVHFローバンド
の周波数、右側の縦軸にUHFバンドの周波数を
とつて、各縦軸にはバンド毎のチヤンネル番号を
付し、VHFハイバンド、VHFローバンド、及び
UHFバンドにおけるチユーナの受信特性の一例
をグラフ化したものである。ここで、VHFハイ
バンドの有局範囲はE5〜E12チヤンネルであり、
VHFローバンドの有局範囲はE2〜E4チヤンネル
であり、UHFバンドの有局範囲はE21〜E60チヤ
ンネルである。 In Figure 6, the horizontal axis shows the tuning voltage Vt, the two vertical axes on the left show the VHF high band and VHF low band frequencies, the right vertical axis shows the UHF band frequency, and each vertical axis shows each band. VHF high band, VHF low band, and
This is a graph showing an example of the reception characteristics of a tuner in the UHF band. Here, the VHF high band station range is E5 to E12 channels,
The VHF low band coverage is E2 to E4 channels, and the UHF band coverage is E21 to E60 channels.
第7図に示す同調周波数プリセツト用の何れか
1つ又は複数の可変抵抗器6を一端から他端まで
摺動させて、全域に亙るスイープ動作を行なう場
合、同調電圧の可変範囲は可変抵抗器の接触抵抗
を見込んでも上述の如く0.2〜30V程度の広い範
囲となる。そのため該電圧範囲の上下端にまで同
調電圧を変化させると、下記の如く余分なスイー
プ動作が行なわれる。 When one or more variable resistors 6 for presetting the tuning frequency shown in FIG. 7 are slid from one end to the other to perform a sweep operation over the entire range, the variable range of the tuning voltage is Even if the contact resistance is taken into account, it will be in a wide range of about 0.2 to 30V as mentioned above. Therefore, when the tuning voltage is changed to the upper and lower ends of the voltage range, an extra sweep operation is performed as described below.
即ち、第6図に示す受信特性から明らかな通
り、VHFローバンドでは、有局範囲の下限チヤ
ンネルE2に対応する同調電圧が略2.5Vで、上限
チヤンネルE4に対応する同調電圧が略10Vである
が、スイープ動作はこの領域を越えて0.2Vから
30Vの範囲で行なわれるから、0.2Vから2.5Vの変
化に相当するチヤンネル変化(E2チヤンネルよ
りも略8MHz低い受信周波数からE2チヤンネルま
で)と、略10Vから30Vまでの変化に相当するチ
ヤンネル変化(E4チヤンネルからE5チヤンネル
を少し越ええるまでの略1.5チヤンネルに相当)
が余分なスイープ動作となる。 That is, as is clear from the reception characteristics shown in Figure 6, in the VHF low band, the tuning voltage corresponding to the lower limit channel E2 of the station range is approximately 2.5V, and the tuning voltage corresponding to the upper limit channel E4 is approximately 10V. , the sweep operation goes beyond this region from 0.2V
Since it is carried out in the 30V range, there is a channel change equivalent to a change from 0.2V to 2.5V (from the reception frequency approximately 8MHz lower than the E2 channel to the E2 channel), and a channel change equivalent to a change from approximately 10V to 30V (from the receiving frequency approximately 8MHz lower than the E2 channel). (Equivalent to approximately 1.5 channels from E4 channel to slightly beyond E5 channel)
is an extra sweep operation.
同様に、VHFハイバンドでは、有局範囲の下
限チヤンネルE5に対応する同調電圧が略4.5Vで、
上限チヤンネルE12に対応する同調電圧が略18V
であるが、スイープ動作はこの領域を越えて
0.2Vから30Vの範囲で行なわれるから、0.2Vから
4.5Vの変化に相当するチヤンネル変化分(数チ
ヤンネル分に相当)と、略18Vから30Vまでの変
化に相当するチヤンネル変化分(E12チヤンネル
から上方へ略2チヤンネル分に相当)が余分なス
イープ動作となる。 Similarly, in the VHF high band, the tuning voltage corresponding to the lower limit channel E5 of the stationed range is approximately 4.5V,
The tuning voltage corresponding to upper limit channel E12 is approximately 18V
However, the sweep operation goes beyond this area.
Since it is carried out in the range of 0.2V to 30V, from 0.2V to
The channel change corresponding to a change of 4.5V (corresponding to several channels) and the channel change corresponding to a change from approximately 18V to 30V (corresponding to approximately 2 channels upward from the E12 channel) are extra sweep operations. becomes.
更にUHFバンドでは、有局範囲の下限チヤン
ネルE21に対応する同調電圧が略3Vで、上限チヤ
ンネルE60に対応する同調電圧が略19Vであるが、
スイープ動作はこの領域を越えて0.2Vから30Vの
範囲で行なわれるから、0.2Vから3Vの変化に相
当するチヤンネル変化分(E21よりも略10チヤン
ネル分低い受信周波数からE21まで)と、略19V
から30Vまでの変化に相当するチヤンネル変化分
(E60チヤンネルから上方へ略13チヤンネル分に
相当)が余分なスイープ動作となる。 Furthermore, in the UHF band, the tuning voltage corresponding to the lower limit channel E21 of the station range is approximately 3V, and the tuning voltage corresponding to the upper limit channel E60 is approximately 19V.
Since the sweep operation is performed in the range from 0.2V to 30V beyond this region, the channel change corresponding to a change from 0.2V to 3V (from the receiving frequency approximately 10 channels lower than E21 to E21) and approximately 19V
The channel change corresponding to the change from to 30V (corresponding to approximately 13 channels upward from the E60 channel) is an extra sweep operation.
一方、通信手段として電波の需要が増加するに
従い、利用可能な周波数帯域を有効に使う為、近
年テレビ標準放送周波数帯の極く近傍まで私的或
は公的通信用として周波数が割り当てられる様に
なつた結果、通常のテレビジヨン装置に於いて
も、何ら改造することなく私的通信の一部が受信
される様になり、通信の秘密を如何に維持するか
が問題となつてきた。 On the other hand, as the demand for radio waves as a means of communication increases, in order to make effective use of the available frequency bands, in recent years, frequencies have been allocated for private and public communications up to the very vicinity of the standard television broadcasting frequency band. As a result, it has become possible for ordinary television equipment to receive some private communications without any modification, and the question of how to maintain the confidentiality of communications has become a problem.
上記問題に対処する為、テレビジヨン受信機に
於ける受信可能範囲を、商業用のテレビ放送のみ
に法律的に規制する動きが各国で起つている。 In order to deal with the above-mentioned problems, there is a movement in various countries to legally limit the reception range of television receivers to only commercial television broadcasts.
例えば西ドイツに於けるFTZ規格、或はカナ
ダに於けるDOC規格がそれで、何れもテレビ受
信機に於けるスイープ範囲の上限及び下限を厳し
く規制している。FTZ規格を例にとると、第6
図に示すUHFバンドに対して878MHzの上限規制
があり、VHFローバンドに対しては、E2チヤン
ネルよりも7MHz低い値に下限が規制されている。 For example, the FTZ standard in West Germany or the DOC standard in Canada both strictly regulate the upper and lower limits of the sweep range in television receivers. Taking the FTZ standard as an example, the 6th standard
The UHF band shown in the figure has an upper limit of 878MHz, and the VHF low band has a lower limit of 7MHz lower than the E2 channel.
上記規格を満足させる簡便な方法として、同調
電圧の可変範囲の最低値Vl(例えば0.5V)に合せ
て各バンドの下限周波数を一致させ、可変範囲の
最高値(例えば30V)で上限周波数に一致する様
に、夫々チユーナの同調周波数を調節することが
考えられる。しかし、同調電圧Vtの可変範囲は
選局部4によつて夫々バラツキがある為、チユー
ナ単独で同調周波数の調節を行なつても、同調電
圧のバラツキによつて同調周波数にずれが生じる
こととなる。従つて、この場合、受信機にチユー
ナを組み込んだ後に受信可能範囲の調節を行なう
必要があり、生産上極めて面倒である。又、同調
電圧Vtの可変範囲下限である0.5V前後の同調電
圧では、チユーナの特性が低下して実用化出来な
い等、問題が多い。 A simple method to satisfy the above standards is to match the lower limit frequency of each band to the lowest value Vl (for example, 0.5V) of the tuning voltage variable range, and match the upper limit frequency at the highest value of the variable range (30V, for example). It is conceivable to adjust the tuning frequency of each tuner so as to do so. However, since the variable range of the tuning voltage Vt varies depending on the tuning section 4, even if the tuning frequency is adjusted by the tuner alone, a shift in the tuning frequency will occur due to the variation in the tuning voltage. . Therefore, in this case, it is necessary to adjust the receivable range after incorporating the tuner into the receiver, which is extremely troublesome in terms of production. Further, when the tuning voltage is around 0.5V, which is the lower limit of the variable range of the tuning voltage Vt, there are many problems such as the characteristics of the tuner deteriorate and it cannot be put to practical use.
(発明の要旨)
本発明は、従来は温度補償を図る為に同調電圧
出力端とチユーナの同調電圧入力端子との間に介
装されているトランジスター71を利用し、該ト
ランジスター71のコレクタ端を上限電圧規制用
の抵抗器を介して電源に繋ぐと共に、エミツタ端
を下限電圧規制用の抵抗器を介して電源に繋い
で、同調電圧の最高値及び最低値を設定すること
により、従来回路に軽微な設計変更を施すだけ
で、性能を落とすことなく容易且つ確実にスイー
プ範囲の規制を行なうことが出来る選局装置を明
らかにするものである。(Summary of the Invention) The present invention utilizes a transistor 71 which has conventionally been interposed between a tuning voltage output terminal and a tuning voltage input terminal of a tuner for temperature compensation, and connects the collector terminal of the transistor 71 to By connecting to the power supply via a resistor for regulating the upper limit voltage and connecting the emitter end to the power supply via a resistor for regulating the lower limit voltage to set the maximum and minimum values of the tuning voltage, it is possible to adapt to the conventional circuit. The purpose of the present invention is to reveal a channel selection device that can easily and reliably regulate the sweep range without degrading performance by making only minor design changes.
(実施例)
以下図面に示す実施例に基づき、本発明を具体
的に説明する。(Example) The present invention will be specifically described below based on an example shown in the drawings.
なお実施例は西ドイツに於けるFTZ規格を想
定して記載したが、他の規格に於いても同様に実
施出来ることは勿論である。 Note that although the embodiment has been described assuming the FTZ standard in West Germany, it goes without saying that it can be implemented in the same way for other standards as well.
第5図は、チユーナ1の一実施例を示すもので
あつて、受信されたVHF及びUHF信号は夫々、
高周波増幅器13で増幅された後、ミキサー14
に於いて、局部発振器15から入力される信号と
混合され、中間周波数IFに変換される。この信
号は更に、従来と同様な信号処理を行ない画像再
生する。局部発振器15には、同調素子として可
変容量ダイオード2が使われており、該ダイオー
ド2に後記する選局部4から出力される同調電圧
Vtを印加することによつて、局部発振器15の
発振周波数を変え、受信周波数を変更する。 FIG. 5 shows an embodiment of the tuner 1, in which the received VHF and UHF signals are
After being amplified by the high frequency amplifier 13, the mixer 14
At , it is mixed with the signal input from the local oscillator 15 and converted into an intermediate frequency IF. This signal is further subjected to signal processing similar to conventional methods to reproduce an image. A variable capacitance diode 2 is used as a tuning element in the local oscillator 15, and a tuning voltage output from a tuning section 4, which will be described later, is applied to the diode 2.
By applying Vt, the oscillation frequency of the local oscillator 15 is changed and the reception frequency is changed.
選局部4は第1の図の如く、UHFバンド、
VHFハイバンド及びVHFローバンドの選択を行
なうバンド切換部44と、選択したチヤンネルに
対応する同調電圧Vtを出力するチヤンネル切換
部5を具え、チヤンネル切換部5から出力され同
調電圧は更に、同調電圧規制回路7にて後記の如
く上下限が規制される。 As shown in the first diagram, the tuning section 4 selects the UHF band,
It includes a band switching unit 44 that selects between VHF high band and VHF low band, and a channel switching unit 5 that outputs a tuning voltage Vt corresponding to the selected channel. The upper and lower limits are regulated by the circuit 7 as described later.
バンド切換部44は、選択可能なチヤンネル数
に対応する数の切換スイツチ45を具え、該スイ
ツチの各固定接点を夫々チユーナ1のバンド切換
端子に繋ぐと共に、摺動接点はダイオード46を
介して、チヤンネル切換部5の切換スイツチ51
に繋ぐ。 The band switching unit 44 includes a number of changeover switches 45 corresponding to the number of selectable channels, and each fixed contact of the switch is connected to a band changeover terminal of the tuner 1, and the sliding contact is connected via a diode 46. Changeover switch 51 of channel changeover section 5
Connect to.
チヤンネル切換部5は、複数組の可変抵抗器
6,6の一端を夫々並列に繋いだ後、定電圧ダイ
オード31で入力電圧Viを安定化する電源3と
接続し、他端は夫々チヤンネル切換スイツチ51
に繋ぐ。該スイツチ51は、チヤンネルボタン
(図示せず)の押圧操作と連繋してオンするトラ
ンジスタスイツチであつて、本実施例ではIC化
したものを使用している。更に各可変抵抗器6の
摺動電極は、スイツチング用ダイオード61を介
して並列接続した後、同調電圧規制回路7に接続
すると共に、バイアス電圧印加用の抵抗R1を介
し電源3に繋ぐ。 The channel switching section 5 connects one end of a plurality of sets of variable resistors 6, 6 in parallel, and then connects it to a power source 3 that stabilizes the input voltage Vi with a constant voltage diode 31, and the other end is connected to a channel switching switch, respectively. 51
Connect to. The switch 51 is a transistor switch that is turned on in conjunction with the pressing operation of a channel button (not shown), and is implemented as an IC in this embodiment. Further, the sliding electrodes of each variable resistor 6 are connected in parallel via a switching diode 61, and then connected to a tuning voltage regulating circuit 7 and to a power source 3 via a bias voltage applying resistor R1.
同調電圧規制回路7は、NPN型トランジスタ
71のベース端をチヤンネル切換部5に繋ぎ、エ
ミツタ端は抵抗R2介して接地すると共に、コレ
クタ端は上限電圧規制用抵抗部8を介して電源3
に繋ぐ。更にNPN型トランジスタ71のエミツ
タ端は、ダイオードDを介してベース端へ接続
し、且つ下限電圧規制用の抵抗部9を介して電源
3へ夫々接続すると共に、フイルタ部Cを通した
後、チユーナ1の同調電圧入力端子18に繋ぐ。 The tuning voltage regulation circuit 7 connects the base end of the NPN type transistor 71 to the channel switching section 5, the emitter end is grounded via the resistor R2 , and the collector end is connected to the power source 3 via the upper limit voltage regulation resistor section 8.
Connect to. Further, the emitter end of the NPN transistor 71 is connected to the base end via the diode D, and is connected to the power supply 3 via the resistor section 9 for lower limit voltage regulation, and after passing through the filter section C, to the tuner. Connect to the tuning voltage input terminal 18 of No. 1.
尚、本実施例では、上限及び下限電圧規制用の
抵抗部8,9として、固定抵抗器R3,R4を使用
しているが、半固定抵抗器に変更しても可い。 In this embodiment, fixed resistors R 3 and R 4 are used as the upper and lower limit voltage regulating resistors 8 and 9, but they may be changed to semi-fixed resistors.
然して、チヤンネルスイツチ51が第2図aの
如くオフ状態の場合、該スイツチ51に繋がれた
可変抵抗器6の出力側に具えたダイオード61の
両端には逆バイアス電圧が印加される為、オフ状
態となる。このとき、他の全てのチヤンネルスイ
ツチ51もオフであれば、同調電圧Vtは出力さ
れない。 However, when the channel switch 51 is in the OFF state as shown in FIG. state. At this time, if all other channel switches 51 are also off, the tuning voltage Vt is not output.
次に第2図bの如く、チヤンネル切換スイツチ
51をオンすると、ダイオード61の両端には順
方向電圧が印加するのでオンし、ダイオード61
のアノード側には、可変抵抗器6からの出力電圧
V0と、ダイオード61の順方向電圧降下Vの和
電圧が出力される。該和電圧(V0+VD)がトラ
ンジスタ71のベース端に印加されると、電圧値
に応じたコレクタ電流が流れ、抵抗器R2の両端
に電圧Vtが出力される。ここでトランジスタ7
1のベース・エミツタ間電圧をVBEとすると、次
の関係式が成立する。 Next, as shown in FIG. 2b, when the channel changeover switch 51 is turned on, a forward voltage is applied to both ends of the diode 61, so the diode 61 is turned on.
The output voltage from variable resistor 6 is on the anode side of
The sum voltage of V 0 and the forward voltage drop V of the diode 61 is output. When the sum voltage (V 0 +V D ) is applied to the base end of the transistor 71, a collector current according to the voltage value flows, and a voltage Vt is output across the resistor R 2 . Here transistor 7
Letting the base-emitter voltage of 1 be V BE , the following relational expression holds true.
V0+VD=Vt+VBE
∴Vt=V0+(VD−VBE) ……(1)
(1)式でVD及びVBEの値及び特性を同一に設定す
ると両者はキヤンセルされ、温度変化によりVD、
VBEの値が変化しても常に
Vt=V0 ……(2)
となつて、定電圧ダイオード31によつて安定化
された基準電圧Vzを可変抵抗器6で分圧した値
V0がそのまま、同調電圧Vtとしてチユーナ1に
印加されるのである。 V 0 +V D = Vt + V BE ∴Vt = V 0 + (V D −V BE ) ...(1) If the values and characteristics of V D and V BE are set to be the same in equation (1), both are canceled and the temperature Due to the change V D ,
Even if the value of V BE changes, Vt=V 0 ...(2) and the value obtained by dividing the reference voltage Vz stabilized by the voltage regulator diode 31 by the variable resistor 6.
V 0 is directly applied to the tuner 1 as the tuning voltage Vt.
尚、フイルタ用コンデンサCは、同調電圧入力
端子18に誘起するリプル電圧吸収用であり、
又、ダイオードDは、可変抵抗器6からの出力電
圧V0が電圧から低圧に急に変化した場合、コン
デサCに充電された電荷をバイパスすることによ
り、応答速度を速めている。 Note that the filter capacitor C is for absorbing ripple voltage induced in the tuning voltage input terminal 18.
Furthermore, when the output voltage V 0 from the variable resistor 6 suddenly changes from a low voltage to a low voltage, the diode D bypasses the charge stored in the capacitor C, thereby increasing the response speed.
次に、可変抵抗器6の摺動電極を低電位側にス
ライドして行くと、スライド位置に応じて出力電
圧は低下して行く。ここでトランジスタ71のエ
ミツタ端には、抵抗R4,R2の接続点が繋がれて
いる為、基準電圧Vzを抵抗R4,R2で分圧した値
をVlとすると、
Vl=Vz/R2+R4×R2≒R2/R4×Vz ……(3)
(ただしR4≫R2)
となり、ベース端の電圧(V0+VD)が第2図c
の如くVl以下になるとトランジスタ71はオフ
され、一定電圧Vlがチユーナ1に印加されるの
である。 Next, when the sliding electrode of the variable resistor 6 is slid toward the lower potential side, the output voltage decreases depending on the sliding position. Here, since the connection point of resistors R 4 and R 2 is connected to the emitter terminal of the transistor 71, if the value obtained by dividing the reference voltage Vz by the resistors R 4 and R 2 is Vl, then Vl=Vz/ R 2 + R 4 × R 2 ≒ R 2 / R 4 × Vz ……(3) (However, R 4 ≫ R 2 ), and the voltage at the base end (V 0 + V D ) is shown in Figure 2c.
When the voltage falls below Vl, the transistor 71 is turned off and a constant voltage Vl is applied to the tuner 1.
上記とは反対に、第2図dの如く、可変抵抗器
6からの出力電圧を上昇させ、トランジスタ71
のベース電流を増加させていくと、最終的に該ト
ランジスター71は飽和領域に達して、コレクタ
電流Icの増加が停止する。この結果、トランジス
タ71のエミツタ端の電圧は、飽和状態に達した
時点コレクタ電圧Vcよりもエミツタ・コレクタ
間電圧VCEだけ低い値Vhに、上限が規制されるの
である。ここで、該エミツタ端の電圧は後述の如
く抵抗R3の値によつて規定される。 In contrast to the above, as shown in FIG. 2d, the output voltage from the variable resistor 6 is increased, and the transistor 71
As the base current of the transistor 71 is increased, the transistor 71 eventually reaches a saturation region and the collector current Ic stops increasing. As a result, the upper limit of the voltage at the emitter terminal of the transistor 71 is regulated to a value Vh lower by the emitter-collector voltage VCE than the collector voltage Vc at the time the transistor 71 reaches the saturated state. Here, the voltage at the emitter terminal is defined by the value of the resistor R3 , as will be described later.
従つて、抵抗R3の値によつてトランジスタ7
1のエミツタ電圧Vhの上限を規制することが出
来る。 Therefore, depending on the value of resistor R3 , transistor 7
The upper limit of the emitter voltage Vh of 1 can be regulated.
上記選局装置の組立工程に於けける受信可能周
波数範囲の調整は、次の様にして行なわれる。 Adjustment of the receivable frequency range in the assembling process of the above-mentioned channel selection device is performed as follows.
VHFローバンドに於けるスイープ範囲に下限
を設定する場合、先ず、FTZ規格等の規制をク
リア出来る下限の周波数(第6図ではE2チヤン
ネルよりも7MHz低い周波数)を決めた後、第6
図のVHFローバンド受信特性から、前記下限周
波数を越え且つ下限チヤンネルE2の受信が可能
となる様な下限の同調電圧Vlを求める。 When setting a lower limit for the sweep range in the VHF low band, first determine the lower limit frequency that can clear regulations such as the FTZ standard (in Figure 6, the frequency is 7MHz lower than the E2 channel), and then
From the VHF low band reception characteristics shown in the figure, a lower limit tuning voltage Vl that exceeds the lower limit frequency and makes it possible to receive the lower limit channel E2 is determined.
前記下限同調電圧Vlは、(3)式の如く抵抗R4と
R2の比によつて規制されるから、(3)式を満足す
る様、抵抗R4を設計する。この結果、可変抵抗
器6を下限一杯まで廻したときに、チユーナ1に
は下限同調電圧Vlが印加されることになる。 The lower limit tuning voltage Vl is determined by the resistance R 4 and the resistance R 4 as shown in equation (3).
Since it is regulated by the ratio of R 2 , design the resistor R 4 to satisfy equation (3). As a result, when the variable resistor 6 is turned to its lower limit, the lower limit tuning voltage Vl is applied to the tuner 1.
更に、前記下限電圧Vlの下で、チユーナ1の
受信範囲を調節すれば、下限周波数の調整は完了
する。 Further, by adjusting the receiving range of the tuner 1 under the lower limit voltage Vl, the adjustment of the lower limit frequency is completed.
次にUHFバンドに於ける受信可能周波数の上
限を設定する場合、上限同調電圧Vhは第6図の
受信特性から決定される。即ち上限同調電圧Vh
を、図中のAで示したバラツキ範囲内(略19V〜
略27V)におさまる様に決定すると、上限同調電
圧が該範囲内の最小値(略19V)となつても、有
局範囲の上限チヤンネルE60の受信可能であり、
然も上限同調電圧が該範囲内の最大値(略27V)
となつても、FTZ規格による規制値(878MHz)
を越えることはない。 Next, when setting the upper limit of the receivable frequency in the UHF band, the upper limit tuning voltage Vh is determined from the reception characteristics shown in FIG. That is, the upper limit tuning voltage Vh
within the variation range shown by A in the figure (approximately 19V~
If the upper limit tuning voltage is determined to be within the range (approximately 27V), even if the upper limit tuning voltage is the minimum value within the range (approximately 19V), it is possible to receive the upper limit channel E60 of the stationed range,
However, the upper limit tuning voltage is the maximum value within the range (approximately 27V)
However, the regulated value according to the FTZ standard (878MHz)
It never exceeds.
又、上限同調電圧Vhを、図中のBで示すバラ
ツキ範囲内(略24.5V〜略27V)におさまる様に
決定すると、上限同調電圧が該範囲内の最小値
(略24.5V)となつても、西ドイツ以外のヨーロ
ツパ各国に於ける有局範囲の上限チヤンネルE69
の受信が可能となり、テレビジヨン放送の受信に
支障がなくなる。 Also, if the upper limit tuning voltage Vh is determined to fall within the variation range shown by B in the figure (approximately 24.5V to approximately 27V), the upper limit tuning voltage will be the minimum value within the range (approximately 24.5V). Also, channel E69 is the upper limit of the station coverage in European countries other than West Germany.
can be received, and there will be no problem in receiving television broadcasts.
次に、第2図dの如く可変抵抗器6を上限一杯
まで廻した時のコレクタ電流Ic及びコレクタ・エ
ミツタ間電圧VCEを求める。この時のエミツタ電
圧Vhは、
Vh=Vz−VCE−Ic×R3 ……(4)
であるから、上限電圧規制用の抵抗部8の抵抗値
R3を(4)式から決定する。この結果、可変抵抗器
6を上限一杯まで廻したときに、チユーナ1には
上限同調電圧Vhが印加されることになる。 Next, as shown in FIG. 2d, the collector current Ic and the collector-emitter voltage VCE when the variable resistor 6 is turned to its upper limit are determined. The emitter voltage Vh at this time is Vh=Vz−V CE −Ic×R 3 ...(4), so the resistance value of the resistor section 8 for regulating the upper limit voltage is
Determine R 3 from equation (4). As a result, when the variable resistor 6 is turned to the full upper limit, the upper limit tuning voltage Vh is applied to the tuner 1.
更に、前記上限電圧Vhの下で、チユーナ1の
受信範囲を調節すれば、上限周波数の調整は完了
する。 Further, by adjusting the reception range of the tuner 1 under the upper limit voltage Vh, the adjustment of the upper limit frequency is completed.
第3図及び第4図は本発明の他の実施例であつ
て、第3図の例では、トランジスタ71のコレク
ター端を抵抗器R5を介して接地している。この
場合、コレクター電圧Vcは、基準電圧Vzはら抵
抗R3による電圧降下分を差引いた値となり、抵
抗R3に流れる電流は、コレター電流Icと抵抗R5
に流れる電流(Vc/R5)の和となるから、次の
式が成立する。 FIGS. 3 and 4 show other embodiments of the present invention, and in the example shown in FIG. 3, the collector end of the transistor 71 is grounded through a resistor R5 . In this case, the collector voltage Vc is the value obtained by subtracting the voltage drop due to the resistor R3 from the reference voltage Vz, and the current flowing through the resistor R3 is the collector current Ic and the resistor R5.
The following equation holds true.
Vc=Vz−R3(Ic+Vc/R5
上式からVcを求めると、
Vc=(Vz/R3+R5−Ic・R3/R3+R5)×R5
なお、R3/R3+R5<1の関係があるから、両辺に
Icを乗じると、上記等式右辺の括弧内の第2項
は、
Ic・R3/R3+V5<Ic
となる。 Vc=Vz−R 3 ( Ic + Vc / R 5Vc is calculated from the above formula . 5 Since there is a relationship of <1, when both sides are multiplied by Ic, the second term in the parentheses on the right side of the above equation becomes Ic・R 3 /R 3 +V 5 <Ic.
ここで、Vz/R3+R5≫Ic
となる様に、R3、R5、Vz、Icの値を予め決める
と、上記等式の右片の括弧内の第2項の値は第1
項の値に比べて微小となる。 Here, if the values of R 3 , R 5 , Vz, and Ic are determined in advance so that Vz/R 3 +R 5 ≫Ic, then the value of the second term in the parentheses on the right side of the above equation is the first
It is very small compared to the value of the term.
従つて
Vc≒VzR5/R3+R5 ……(5)
となり、Vcの値はIcの値に拘わらず一定となつ
て、Vcの設定が容易となる。 Therefore, Vc≈VzR 5 /R 3 +R 5 (5), and the value of Vc remains constant regardless of the value of Ic, making it easy to set Vc.
第4図の実施例では、更に抵抗器R3の両端に
半固定抵抗器R6が接続されており、従つて上限
電圧の微調節が可能となる。 In the embodiment shown in FIG. 4, a semi-fixed resistor R6 is further connected to both ends of the resistor R3 , thus making it possible to finely adjust the upper limit voltage.
本発明は上記の如く、同調電圧規制回路7に装
備したトランジスター71のエミツタ端に抵抗器
R4を介装してエミツタ電圧を規制することによ
り、同調電圧の下限を規制すると共に、コレクタ
側に抵抗器R3を介装してコレクタ電圧を規制す
ることにより、同調電圧の上限を規制したので、
従来の回路の軽微な設計変更だけで製造ラインを
殆んど変更することなく容易に製造が出来、しか
も何ら性能を落とすことなく、確実且つ容易に受
信可能周波数帯域の制限を行なうことが出来る
等、優れた効果を有する。 As described above, the present invention includes a resistor at the emitter terminal of the transistor 71 installed in the tuning voltage regulating circuit 7.
By interposing R 4 to regulate the emitter voltage, the lower limit of the tuning voltage is regulated, and by interposing resistor R 3 on the collector side to regulate the collector voltage, the upper limit of the tuning voltage is regulated. So,
It can be easily manufactured with only minor design changes to conventional circuits and almost no changes to the production line, and the receivable frequency band can be reliably and easily restricted without any deterioration in performance. , has excellent effects.
第1図は本発明にかかる選局装置の一例を示す
電気回路図、第2図aはチヤンネルスイツチがオ
フ状態の時、第2図bはチヤンネルスイツチがオ
ンした時、第2図cは下限電圧の規制状況を、第
2図dは上限電圧の規制状況を夫々示す説明図、
第3図及び第4図は他の実施例を示す電気回路
図、第5図はチユーナの概略を示すブロツク図、
第6図はチユーナの受信特性の一例を示すグラ
フ、第7図は従来装置を示す電気回路図である。
1……チユーナ、2……可変容量ダイオード、
5……チヤンネル切換部、6……可変抵抗器、6
1……スイツチング用ダイオード、7……同調電
圧規制回路、8,9……抵抗部。
Fig. 1 is an electric circuit diagram showing an example of a channel selection device according to the present invention, Fig. 2a is when the channel switch is off, Fig. 2b is when the channel switch is on, and Fig. 2c is the lower limit. Figure 2d is an explanatory diagram showing the voltage regulation situation, and Fig. 2d is an explanatory diagram showing the upper limit voltage regulation situation, respectively.
3 and 4 are electric circuit diagrams showing other embodiments, and FIG. 5 is a block diagram showing an outline of the tuner.
FIG. 6 is a graph showing an example of reception characteristics of a tuner, and FIG. 7 is an electric circuit diagram showing a conventional device. 1... tuner, 2... variable capacitance diode,
5...Channel switching unit, 6...Variable resistor, 6
1... Switching diode, 7... Tuning voltage regulation circuit, 8, 9... Resistance section.
Claims (1)
チユーナ1と、該可変容量ダイオードへ供給すべ
き同調電圧を出力する選局部4とを装備し、該選
局部4は、所定の基準電圧Vzを分圧して受信チ
ヤンネル毎の同調電圧を形成する複数の可変抵抗
器6を具え、各可変抵抗器の出力端は夫々スイツ
チング用ダイオード61を介して互いに連結し、
該連結点に前記選局部4の同調電圧出力端を設け
た選局装置に於いて、選局部4とチユーナ1との
間に同調電圧規制回路7を介装し、該同調電圧規
制回路7はNPN型トランジスター71を具え、
該トランジスター71のベース端は選局部4の同
調電圧出力端に繋ぎ、エミツタ端はチユーナ1の
同調電圧入力端子に繋ぐと共に抵抗器を介して接
地し、且つ該トランジスターのエミツター端は下
限電圧規制用の第1抵抗部9を介して電源に繋ぐ
と共に、該トランジスター71のコレクタ端は上
限電圧規制用の第2抵抗部8を介して電源に繋
ぎ、これによつてエミツタ電圧の下限及びコレク
タ電圧の上限を規制して、出力同調電圧の下限及
び上限を規制したことを特徴とする選局装置。 2 第1抵抗部9及び第2抵抗部8は、固定又は
可変抵抗器である特許請求の範囲第1項に記載の
選局装置。 3 第2抵抗部8は、基準電圧を分圧する複数の
抵抗器を具え、該抵抗器により分圧された電圧が
トランジスター71のコレクタ端に印加されてい
る特許請求の範囲第1項に記載の選局装置。 4 第2抵抗部8は、トランジスター71のコレ
クタ端と基準電圧点との間に、第1の固定抵抗器
及び可変抵抗器を互いに並列に介装すると共に、
トランジスター71のコレクタ端は、第2の固定
抵抗器を介して接地している特許請求の範囲第1
項に記載の選局装置。[Claims] 1 Equipped with a tuner 1 equipped with a variable capacitance diode as a tuning element, and a tuning section 4 that outputs a tuning voltage to be supplied to the variable capacitance diode, the tuning section 4 It is equipped with a plurality of variable resistors 6 that divide the voltage Vz to form a tuning voltage for each reception channel, and the output terminals of each variable resistor are connected to each other via switching diodes 61, respectively.
In the tuning device in which the tuning voltage output terminal of the tuning section 4 is provided at the connection point, a tuning voltage regulating circuit 7 is interposed between the tuning section 4 and the tuner 1, and the tuning voltage regulating circuit 7 is Equipped with an NPN type transistor 71,
The base end of the transistor 71 is connected to the tuning voltage output terminal of the tuning section 4, the emitter end is connected to the tuning voltage input terminal of the tuner 1 and grounded via a resistor, and the emitter end of the transistor is used for lower limit voltage regulation. The collector end of the transistor 71 is connected to the power supply via the first resistor section 9 for regulating the upper limit voltage, and the collector end of the transistor 71 is connected to the power supply via the second resistor section 8 for regulating the upper limit voltage. A tuning device characterized in that an upper limit is regulated, and a lower limit and an upper limit of an output tuning voltage are regulated. 2. The channel selection device according to claim 1, wherein the first resistance section 9 and the second resistance section 8 are fixed or variable resistors. 3. The second resistor section 8 includes a plurality of resistors that divide the reference voltage, and the voltage divided by the resistors is applied to the collector end of the transistor 71. Channel selection device. 4. The second resistor section 8 has a first fixed resistor and a variable resistor interposed in parallel between the collector end of the transistor 71 and the reference voltage point, and
The collector end of the transistor 71 is grounded via a second fixed resistor.
The channel selection device described in section.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2095580A JPS56117419A (en) | 1980-02-20 | 1980-02-20 | Channel selector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2095580A JPS56117419A (en) | 1980-02-20 | 1980-02-20 | Channel selector |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS56117419A JPS56117419A (en) | 1981-09-14 |
JPH0145248B2 true JPH0145248B2 (en) | 1989-10-03 |
Family
ID=12041599
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2095580A Granted JPS56117419A (en) | 1980-02-20 | 1980-02-20 | Channel selector |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS56117419A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010283486A (en) * | 2009-06-03 | 2010-12-16 | Casio Computer Co Ltd | Radio wave receiver |
-
1980
- 1980-02-20 JP JP2095580A patent/JPS56117419A/en active Granted
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010283486A (en) * | 2009-06-03 | 2010-12-16 | Casio Computer Co Ltd | Radio wave receiver |
US8270922B2 (en) | 2009-06-03 | 2012-09-18 | Casio Computer Co., Ltd. | Radio wave receiver |
Also Published As
Publication number | Publication date |
---|---|
JPS56117419A (en) | 1981-09-14 |
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