JPS6271622U - - Google Patents
Info
- Publication number
- JPS6271622U JPS6271622U JP16444785U JP16444785U JPS6271622U JP S6271622 U JPS6271622 U JP S6271622U JP 16444785 U JP16444785 U JP 16444785U JP 16444785 U JP16444785 U JP 16444785U JP S6271622 U JPS6271622 U JP S6271622U
- Authority
- JP
- Japan
- Prior art keywords
- current
- mirror circuit
- circuit
- constant current
- added
- 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.)
- Pending
Links
- 238000006243 chemical reaction Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 1
Landscapes
- Exposure Control For Cameras (AREA)
- Shutters For Cameras (AREA)
- Indication In Cameras, And Counting Of Exposures (AREA)
Description
第１図は本考案による一実施例を示す回路図、
第２図は同回路の動作を説明するための光電流と
積分電流及び報知信号の関係図である。
Ｑ１：ホトトランジスタ、Ｃ：積分用コンデン
サ、Ｉｒｅｆ：定電流、Ｑ２，Ｑ３，Ｑ５，Ｑ８
，Ｑ４，Ｑ１０，Ｑ１２，Ｑ１３，Ｑ９，Ｑ１１
：カレントミラ回路、Ｑ６，Ｑ７：報知信号形成
トランジスタ。
FIG. 1 is a circuit diagram showing an embodiment of the present invention;
FIG. 2 is a relationship diagram of photocurrent, integral current, and notification signal for explaining the operation of the circuit. Q 1 : Phototransistor, C: Integrating capacitor, I ref : Constant current, Q 2 , Q 3 , Q 5 , Q 8
, Q 4 , Q 10 , Q 12 , Q 13 , Q 9 , Q 11
: Current mirror circuit, Q 6 , Q 7 : Notification signal forming transistor.
Claims (1)
を加えて、両電流の差の電流をカレントミラ回路
に入力し、該カレントミラ回路の出力電流に、第
２の定電流を加えてシヤツタ制御のための積分電
流を形成するシヤツタ制御回路において、 上記カレントミラ回路の出力電流がベースに与
えられたＰＮＰトランジスタを設けてなり、該Ｐ
ＮＰトランジスタのコレクタ電流のオン・オフで
光電流が予め定められたリミツタ作動域にあるか
否かの判定信号とすることを特徴とする低輝度報
知回路。[Claims for Utility Model Registration] A first constant current is added to the photocurrent generated in the photoelectric conversion element, the difference between the two currents is inputted to a current mirror circuit, and the output current of the current mirror circuit is added to the first constant current. A shutter control circuit that adds a constant current of 2 to form an integral current for shutter control is provided with a PNP transistor whose base is given the output current of the current mirror circuit,
A low brightness alarm circuit characterized in that turning on and off a collector current of an NP transistor is used as a determination signal for determining whether a photocurrent is within a predetermined limiter operating range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16444785U JPS6271622U (en) | 1985-10-23 | 1985-10-23 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16444785U JPS6271622U (en) | 1985-10-23 | 1985-10-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6271622U true JPS6271622U (en) | 1987-05-07 |
Family
ID=31093572
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16444785U Pending JPS6271622U (en) | 1985-10-23 | 1985-10-23 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6271622U (en) |
-
1985
- 1985-10-23 JP JP16444785U patent/JPS6271622U/ja active Pending