GB528310A - Improvements in or relating to thermionic valve circuits - Google Patents
Improvements in or relating to thermionic valve circuitsInfo
- Publication number
- GB528310A GB528310A GB626639A GB626639A GB528310A GB 528310 A GB528310 A GB 528310A GB 626639 A GB626639 A GB 626639A GB 626639 A GB626639 A GB 626639A GB 528310 A GB528310 A GB 528310A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- pulse
- pulses
- impulses
- network
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
- H04N5/06—Generation of synchronising signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/04—Synchronising
- H04N5/08—Separation of synchronising signals from picture signals
- H04N5/10—Separation of line synchronising signal from frame synchronising signal or vice versa
Abstract
528,310. Television ; valve generating circuits; impedance networks. BLUMLEIN, A. D. Feb. 25, 1939, No. 6266. [Classes 40 (iii) and 40 (v)] Delay networks with mismatched terminations producing reflection are used for producing timed impulses or for separating long and short impulses, e.g. line and frame synchronizing impulses. The network may be open-circuited or short-circuited so that the reflected impulses are of the same or opposite polarity. Producing impulses of predetermined duration from sawtoothwaves, or from impulses of longer duration, or at timed intervals. The network 4, Fig. 1, is short-circuited at 10 and terminated at its input end by an impedance 1, 2, 3 equal to the characteristic impedance of the network. Pulses, produced or repeated by valve 1, reaching the tapping point 5 render the valve 7 conductive, and the reflected pulses of opposite polarity render it non-conductive. The duration of the pulses at the anode of valve 7 is thus equal to twice the time taken by the pulse to travel from 5 to 10. The valve 7 may be replaced by a pair of valves in push-pull, as in Specification 482,740. Two consecutive pulses may be generated from a single input pulse by the arrangement shown in Fig. 2, in which the valves 14, 15 are so biased that when one is conducting the other is not. The initial pulse reaching the tapping 16 renders the valve 14 conducting until the pulse reaches tapping 17 and makes valve 15 conducting and valve 14 non-conducting. After an interval during which the pulse travels to 18 and back to 17, the valve 15 is rendered non- conducting and the valve 14 conducting until the pulse reaches 16 and renders 14 non-conduct. ing. The output of the double-frequency pulses may be obtained from either 14 or 15, their duration and the interval between them being determined by the position of the tappings 16, 17. A circuit similar to that shown in Fig. 1 may be used for producing (for A.V.C. or D.C. insertion) a pulse of, say, 4 microseconds beginning slightly after and ending slightly before an observation pulse of 5 microseconds following the line synchronizing pulse, Fig. 3 (not shown). Other similar applications are described. Separating vision, line and frame synchronizing impulses. The network is open-circuited so that the reflected impulse is of the same polarity as the initial pulse, and the delay caused by the network is greater than the duration of the line pulse but less than that of the frame pulse ; the reflected frame pulse reinforces the initial pulse so that the line and frame pulses may be separated by an amplitude filter. In the circuit shown in Fig. 4, vision signals are taken off by lead 31 from a valve 29 of the cathode follower type, the line synchronizing pulses are separated by valve 32, the cathode of which is connected by a self-biasing resistance-capacity combination 33, 34 to the cathode of valve 29 and the frame synchronizing pulses are derived from a valve 37 connected to the input end of the delay network so as to be influenced by the reflected overlapping frame pulses. During synchronizing signals, the valve 32 absorbs current which would normally flow to valve 29, thus increasing the current change due to synchronizing signals in valve 29 and producing large signals across the delay network. The delay in the derivation of the frame pulse is useful in interlaced scanning. Impedance networks. The coils of adjacent sections may be coupled, and m-derived sections may adjoin the terminations. As the delay is not constant for frequencies approaching the cut-off, the first coil or coils may be shunted with high resistance to attenuate the high frequencies. Specifications 422,906, 449,242, 458,585, 491,728, 496,119, 514,065, 514,271 also are referred to. Reference has been directed by the Comptroller to Specifications 531,712 and 538,553.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB626639A GB528310A (en) | 1939-02-25 | 1939-02-25 | Improvements in or relating to thermionic valve circuits |
FR874393D FR874393A (en) | 1939-02-25 | 1940-02-24 | Improvement in circuits including thermionic lamps |
DE1950E0001995 DE837251C (en) | 1939-02-25 | 1950-08-25 | Circuit arrangement for generating or separating electrical pulses |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB626639A GB528310A (en) | 1939-02-25 | 1939-02-25 | Improvements in or relating to thermionic valve circuits |
Publications (1)
Publication Number | Publication Date |
---|---|
GB528310A true GB528310A (en) | 1940-10-28 |
Family
ID=9811387
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB626639A Expired GB528310A (en) | 1939-02-25 | 1939-02-25 | Improvements in or relating to thermionic valve circuits |
Country Status (3)
Country | Link |
---|---|
DE (1) | DE837251C (en) |
FR (1) | FR874393A (en) |
GB (1) | GB528310A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE961809C (en) * | 1941-07-08 | 1957-04-11 | Int Standard Electric Corp | Multivibrator |
DE1029877B (en) * | 1952-11-28 | 1958-05-14 | Philips Nv | Circuit arrangement for generating pulses |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2922965A (en) * | 1956-08-09 | 1960-01-26 | Bell Telephone Labor Inc | Aperture equalizer and phase correction for television |
-
1939
- 1939-02-25 GB GB626639A patent/GB528310A/en not_active Expired
-
1940
- 1940-02-24 FR FR874393D patent/FR874393A/en not_active Expired
-
1950
- 1950-08-25 DE DE1950E0001995 patent/DE837251C/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE961809C (en) * | 1941-07-08 | 1957-04-11 | Int Standard Electric Corp | Multivibrator |
DE1029877B (en) * | 1952-11-28 | 1958-05-14 | Philips Nv | Circuit arrangement for generating pulses |
Also Published As
Publication number | Publication date |
---|---|
DE837251C (en) | 1952-04-21 |
FR874393A (en) | 1942-08-05 |
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