JPS56129485A - Reproduction circuit for dc component - Google Patents
Reproduction circuit for dc componentInfo
- Publication number
- JPS56129485A JPS56129485A JP3266680A JP3266680A JPS56129485A JP S56129485 A JPS56129485 A JP S56129485A JP 3266680 A JP3266680 A JP 3266680A JP 3266680 A JP3266680 A JP 3266680A JP S56129485 A JPS56129485 A JP S56129485A
- Authority
- JP
- Japan
- Prior art keywords
- diodes
- emitter
- collector
- clamp
- switching 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
- H04N5/18—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level by means of "clamp" circuit operated by switching circuit
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Picture Signal Circuits (AREA)
- Manipulation Of Pulses (AREA)
Abstract
PURPOSE:To prevent the damage of switching transistor due to abnormal voltage caused by in-tube discharge of CRT and the system down, by connecting one or a plurality of diodes in parallel between the emitter and collector of switching transistor for pulse clamp. CONSTITUTION:At every time when synchronizing pulse is inputted to the synchronizing signal input terminal 2, the switching transistor TR5 is conductive and the output side of a capacitor 3 is fixed to the clamp level set with a variable resistor 9, and the black level of video signal from the video signal input terminal 1 is fixed to the clamp level. When TR5 is conductive, the voltage between the emitter and collector of TR5 is selected smaller than the forward voltage of diodes 12, 13 between the emitter and collector of TR5 so that the diodes 12, 13 cannot give any effect on normal clamp operation. Further, when in-tube discharge is caused in CRT and high voltage is given to the output terminal 11, the diodes 12, 13 are conducted to prevent the damage of TR5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3266680A JPS56129485A (en) | 1980-03-17 | 1980-03-17 | Reproduction circuit for dc component |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3266680A JPS56129485A (en) | 1980-03-17 | 1980-03-17 | Reproduction circuit for dc component |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS56129485A true JPS56129485A (en) | 1981-10-09 |
Family
ID=12365187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3266680A Pending JPS56129485A (en) | 1980-03-17 | 1980-03-17 | Reproduction circuit for dc component |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56129485A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58100576A (en) * | 1981-12-11 | 1983-06-15 | Hitachi Ltd | Video clamp circuit |
| JP2010258813A (en) * | 2009-04-24 | 2010-11-11 | Mitsumi Electric Co Ltd | Image signal input circuit |
| CN109474246A (en) * | 2018-10-31 | 2019-03-15 | 西安微电子技术研究所 | Voltage clamp protects structure and operational amplifier input stage structure |
-
1980
- 1980-03-17 JP JP3266680A patent/JPS56129485A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58100576A (en) * | 1981-12-11 | 1983-06-15 | Hitachi Ltd | Video clamp circuit |
| JP2010258813A (en) * | 2009-04-24 | 2010-11-11 | Mitsumi Electric Co Ltd | Image signal input circuit |
| CN109474246A (en) * | 2018-10-31 | 2019-03-15 | 西安微电子技术研究所 | Voltage clamp protects structure and operational amplifier input stage structure |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4470066A (en) | Circuit arrangement for adjusting the direct current level of a video signal | |
| US2933625A (en) | Multiple delay circuit | |
| US2820153A (en) | Electronic counter systems | |
| GB1121021A (en) | Noise protection circuit | |
| JPS56129485A (en) | Reproduction circuit for dc component | |
| US3283259A (en) | Pulse distribution amplifier | |
| US3821564A (en) | Control circuit for a thyristor | |
| US2956118A (en) | Selective amplitude discriminatory circuit | |
| US2295346A (en) | Television and like system | |
| US3001086A (en) | Linear sweep circuit arrangements | |
| US3532811A (en) | Circuit for separating sync signals from a composite video signal | |
| US3906304A (en) | High voltage protection circuit | |
| US2713119A (en) | Switching equipment | |
| US3793540A (en) | Constant current source for time delay device | |
| GB1267979A (en) | Synchronizing separator circuits | |
| GB2146862A (en) | Electronic switching circuits | |
| SU966899A1 (en) | Device for setting logic elements into initial state | |
| JPS6446328A (en) | Input protection circuit device for signal receiver | |
| US3979605A (en) | Integrating circuit for separating a wide pulse from a narrow pulse | |
| US3363055A (en) | Arrangement for reinserting the d.c. component into a signal with periodically recurrent reference values | |
| GB1220955A (en) | Protection circuit | |
| US4155101A (en) | Gating circuit for use with camera incorporating highlight overload protection | |
| GB928172A (en) | Improvements relating to telephone exchange systems | |
| MY105908A (en) | Video recorder with generation of a text signal. | |
| US3953747A (en) | AC wave switching circuit using at least one switching transistor |