JPH0532872Y2 - - Google Patents
Info
- Publication number
- JPH0532872Y2 JPH0532872Y2 JP14657185U JP14657185U JPH0532872Y2 JP H0532872 Y2 JPH0532872 Y2 JP H0532872Y2 JP 14657185 U JP14657185 U JP 14657185U JP 14657185 U JP14657185 U JP 14657185U JP H0532872 Y2 JPH0532872 Y2 JP H0532872Y2
- Authority
- JP
- Japan
- Prior art keywords
- current
- brightness
- resistor
- differential amplifier
- inverting input
- 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 - Lifetime
Links
- 230000003321 amplification Effects 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Landscapes
- Control Of Amplification And Gain Control (AREA)
- Amplifiers (AREA)
- Television Receiver Circuits (AREA)
Description
【考案の詳細な説明】
（技術分野）
この考案はオシロスコープ等の輝度制御回路の
改良に関するものである。[Detailed Description of the Invention] (Technical Field) This invention relates to improvement of brightness control circuits for oscilloscopes and the like.
（従来技術とその問題点）
第３図に従来の輝度制御回路を示す。１は輝度
電流制御用可変抵抗器で、２は電圧を電流に変換
するための抵抗器で、３はNPN形トランジスタ
で、４は輝度増幅器で、５はブラウン管である。
その動作はNPN形トランジスタ３のベースーエ
ミツタ間電圧（以下、VBEと略す）と電源−Ｖと
の電位差と可変抵抗器１の移動端子と電源との間
の抵抗値R2と抵抗器２の抵抗値R1の和の合成抵
抗との除算により決定する輝度電流をNPN形ト
ランジスタ３に流し輝度増幅器４に伝達する。さ
らにブラウン管５の表示輝度を制御するものであ
る。ここで、輝度電流は抵抗器２とNPN形トラ
ンジスタ３のVBEに依存することになり抵抗値と
VBEが直接輝度電流に影響するため抵抗値は厳選
する必要があり、選択の融通性がなかつた。ま
た、トランジスタ３の自己発熱等による温度変化
によりVBEが変化し、輝度電流の安定化が困難で
あつた。(Prior art and its problems) FIG. 3 shows a conventional brightness control circuit. 1 is a variable resistor for brightness current control, 2 is a resistor for converting voltage into current, 3 is an NPN transistor, 4 is a brightness amplifier, and 5 is a cathode ray tube.
Its operation consists of the potential difference between the base-emitter voltage (hereinafter abbreviated as V BE ) of the NPN transistor 3 and the power supply -V, the resistance value R 2 between the moving terminal of the variable resistor 1 and the power supply, and the resistance of the resistor 2. A brightness current determined by dividing the sum of the values R1 by the combined resistance is passed through the NPN transistor 3 and transmitted to the brightness amplifier 4. Furthermore, the display brightness of the cathode ray tube 5 is controlled. Here, the brightness current depends on the V BE of resistor 2 and NPN transistor 3, so the resistance value and
Since V BE directly affects the brightness current, the resistance value must be carefully selected, and there is no flexibility in selection. Furthermore, V BE changes due to temperature changes due to self-heating of the transistor 3, making it difficult to stabilize the brightness current.
（目的）
この考案はこれらの欠点を除去するため、輝度
電流を決定する要素を抵抗比とすることと、差動
増幅器を有することを特徴とし、その目的は輝度
電流を決定するための抵抗定数選択に融通性をも
たせることと輝度電流の温度に対する変動を軽減
し、より安定化を図ることにある。(Purpose) In order to eliminate these drawbacks, this invention is characterized by using a resistance ratio as the element that determines the brightness current and by having a differential amplifier. The purpose is to provide flexibility in selection and to reduce fluctuations in brightness current with respect to temperature, thereby making it more stable.
（実施例）
以下にこの考案の実施例を第１図により説明す
る。６は電流増幅回路で、その構成はNPN形ト
ランジスタ３と差動増幅器７と帰還回路である抵
抗値REの抵抗器８、抵抗値RFの抵抗器９とから
成る。(Example) An example of this invention will be described below with reference to FIG. Reference numeral 6 denotes a current amplification circuit, which is composed of an NPN transistor 3, a differential amplifier 7, a feedback circuit, a resistor 8 having a resistance value R E , and a resistor 9 having a resistance value R F.
次にこの動作について説明する。差動増幅器７
の符号非反転入力を接地することにより、符号反
転入力も接地レベルとなるべく動作する。符号反
転入力には電流値Iiの入力電流１０を流すための
従来と同様の電流源回路とNPN形トランジスタ
３の電流値Io出力電流１１からの帰還回路として
の抵抗器８，９を接続する。 Next, this operation will be explained. Differential amplifier 7
By grounding the sign non-inverting input of the circuit, the sign-inverting input also operates to be at the ground level. A current source circuit similar to the conventional one for flowing an input current 10 having a current value Ii and resistors 8 and 9 as a feedback circuit from the output current 11 having a current value Io of the NPN transistor 3 are connected to the sign-inverted input.
今、差動増幅器７の符号反転入力は接地レベ
ル、すなわち0Vである。 Now, the sign-inverting input of the differential amplifier 7 is at ground level, that is, 0V.
また、この入力インピーダンスは比較的大き
い。したがつて抵抗値RFの抵抗器９に流れる電
流は電流値Iiの入力電流１０に等しい。 Also, this input impedance is relatively large. Therefore, the current flowing through the resistor 9 having the resistance value R F is equal to the input current 10 having the current value Ii.
また、抵抗値REの抵抗器８に流れる電流１２
をIEとする。さらに、NPNトランジスタのコレ
クタに流れ込む電流値IOの出力電流１１は、ほぼ
エミツタに流れる電流に等しい。抵抗器８と９の
接続点の電圧１３の電圧値をEOする。 Also, a current 12 flows through a resistor 8 having a resistance value RE .
Let I E be the current flowing into the collector of the NPN transistor. The output current 11, which has a current value I O that flows into the collector, is approximately equal to the current flowing into the emitter. Let the voltage value of the voltage 13 at the connection point between resistors 8 and 9 be E O.
以上のことから連立方程式を立てると次のよう
になる。 From the above, we can create a simultaneous equation as follows.
EO＝Ii×RF＝IE×RE
IO＝Ii＋IE ……(1)
……(2)
(1)式を変形して IE＝RF／RE×Ii ……(3)
(3)式を(2)式に代入して整理すると
IO＝（１＋RF／RE）Ii ……(4)
となる。従つて(4)式から、この電流増幅回路６の
電流増幅度はIO／Ii＝（１＋RF／RE）で表わされ
る。E O = Ii × R F = I E ×R E I O = Ii + I E ……(1) ……(2) Transforming equation (1), I E = R F /R E ×Ii ……(3 ) Substituting equation (3) into equation (2) and sorting it out, I O = (1 + R F /R E )Ii ... (4). Therefore, from equation (4), the current amplification degree of this current amplification circuit 6 is expressed as I O /Ii=(1+ RF /R E ).
すなわち、輝度電流である出力電流（IO）１１
は抵抗器（RF）９と抵抗器（RE）８との抵抗比
と入力電流（Ii）１０の積となる。 That is, the output current (I O ) 11 which is the brightness current
is the product of the resistance ratio of the resistor (R F ) 9 and the resistor (R E ) 8 and the input current (Ii) 10.
また、差動増幅器７をトランジスタを用いて第
２図の如く構成することもできる。 Further, the differential amplifier 7 can also be constructed using transistors as shown in FIG.
（効果）
この考案による輝度制御回路は抵抗値に依存し
て輝度電流を制御するのでなく抵抗比に依存して
輝度電流を制御するため所定の輝度電流を流すた
めの抵抗値の選択は従来に比べ定数の選定が容易
になる。また、従来の如く輝度電流を決定する要
因にトランジスタのベースーエミツタ間電圧が直
接関係していないため温度変化に対する輝度電流
の安定化を図ることができる。さらにこの電流増
幅回路が抵抗比により出力電流を決定できること
と、差動増幅器を採用していることに着目すると
集積回路化に適していることがわかる。集積回路
とした場合は抵抗の温度係数も一様となり、抵抗
比として、より安定な値がとれる。また、差動増
幅器のエミツタ結合対トランジスタの熱結合度も
上がるため、温度変化に対する輝度電流の安定化
を図ることができる。(Effects) The brightness control circuit according to this invention does not control the brightness current depending on the resistance value, but controls the brightness current depending on the resistance ratio. Comparison constant selection becomes easy. Further, since the base-emitter voltage of the transistor is not directly related to the factor that determines the brightness current as in the prior art, the brightness current can be stabilized against temperature changes. Furthermore, it can be seen that this current amplifier circuit is suitable for integration into an integrated circuit by noting that the output current can be determined by the resistance ratio and that it uses a differential amplifier. When an integrated circuit is used, the temperature coefficient of resistance becomes uniform, and the resistance ratio can take a more stable value. Further, since the degree of thermal coupling between the emitter-coupled transistors of the differential amplifier is also increased, it is possible to stabilize the brightness current against temperature changes.
第１図及び第２図は本考案の一実施例を示す回
路図である。第３図は従来の輝度制御回路の例を
示す図。
１……輝度電流制御用可変抵抗器、３……
NPN形トランジスタ、４……輝度増幅器、５…
…ブラウン管、６……電流増幅回路、７……差動
増幅器、１０……入力電流、１１……出力電流
（輝度電流）。
1 and 2 are circuit diagrams showing one embodiment of the present invention. FIG. 3 is a diagram showing an example of a conventional brightness control circuit. 1... Variable resistor for brightness current control, 3...
NPN transistor, 4... Brightness amplifier, 5...
... Braun tube, 6 ... Current amplification circuit, 7 ... Differential amplifier, 10 ... Input current, 11 ... Output current (luminance current).
Claims (1)
動端と直列に接続された抵抗と、該抵抗の他端に
反転入力端を接続し、非反転入力端を接地した差
動増幅器と、該差動増幅器の出力端とベースを接
続し、エミツタを抵抗を介して接地し、コレクタ
を次段の輝度増幅器に接続したトランジスタと、
該トランジスタのエミツタと前記差動増幅器の反
転入力端との間に接続した抵抗より成る輝度制御
回路。 a brightness current control variable resistor, a resistor connected in series with a sliding end of the variable resistor, a differential amplifier having an inverting input terminal connected to the other end of the resistor and a non-inverting input terminal grounded; a transistor whose output terminal and base of the differential amplifier are connected, whose emitter is grounded via a resistor, and whose collector is connected to a brightness amplifier at the next stage;
A brightness control circuit comprising a resistor connected between the emitter of the transistor and the inverting input terminal of the differential amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14657185U JPH0532872Y2 (en) | 1985-09-27 | 1985-09-27 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14657185U JPH0532872Y2 (en) | 1985-09-27 | 1985-09-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6255177U JPS6255177U (en) | 1987-04-06 |
| JPH0532872Y2 true JPH0532872Y2 (en) | 1993-08-23 |
Family
ID=31059158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14657185U Expired - Lifetime JPH0532872Y2 (en) | 1985-09-27 | 1985-09-27 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0532872Y2 (en) |
-
1985
- 1985-09-27 JP JP14657185U patent/JPH0532872Y2/ja not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6255177U (en) | 1987-04-06 |
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