GB1395919A - Device for automatic tuning of television receivers - Google Patents
Device for automatic tuning of television receiversInfo
- Publication number
- GB1395919A GB1395919A GB2408972A GB2408972A GB1395919A GB 1395919 A GB1395919 A GB 1395919A GB 2408972 A GB2408972 A GB 2408972A GB 2408972 A GB2408972 A GB 2408972A GB 1395919 A GB1395919 A GB 1395919A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signal
- sweep
- generator
- circuit
- receiver
- 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
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/50—Tuning indicators; Automatic tuning control
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/18—Automatic scanning over a band of frequencies
- H03J7/20—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element
- H03J7/24—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element using varactors, i.e. voltage variable reactive diodes
Abstract
1395919 Touch responsive switches AUTOVOX SpA 23 May 1972 24089/72 Heading G1N [Also in Division H3] In a device for automatic tuning of a TV receiver having a variable capacity diode tuner, the device has a sawtooth generator 1, Fig. 2, producing a sawtooth biasing signal g for the variable capacity diode and for a band switching circuit (2), Fig. 1 (not shown) and Fig. 3, when a video carrier signal l applied to an amplifier, limiter and discriminator circuit 4 is present a control signal is produced which is applied to operate a blocking circuit 5 so as to stop sweep operation of the sawtooth generator 1 and an electronic switch 11 is operated to allow the supply of the control signal to the blocking circuit 5 on receipt of a rectified sound intercarrier signal c so as to stop the sweep operation of the sawtooth generator 1. On switching on, transistors Q001, Q002, Fig. 3, switch on and a band feed voltage for the tuner is applied from I. The capacitor C179, Fig. 2 of the sawtooth generator 1 is charged via Q154 and the 0.3 secs sweep is ended by Q156, Q157. The change in output at g operates Q013 to turn Q003, Q004 on and turn Q001, Q002 off so as to provide a different band switching voltage at 111 and to connect different timing resistors to the sawtooth generator 1 at e, f to alter the next sweep time to 0.6 secs. Similarly at the end of this sweep Q005, Q006 turn on to connect the UHF band switching voltage and provide a further sweep time of 2 secs. At the end of this time the first stage Q001, Q002 is turned on again and the above is repeated. The transistor Q153 of the signal search circuit is maintained blocked by the negative potential at i when no television signal is received. If an I.F. sound intercarrier signal occurs at c it operates via intercarrier amplifier 6 and intercarrier detector 8 on electronic switching unit 11 so that transistor Q152 conducts to remove the negative potential at i. If an I.F. video carrier signal now occurs at I the amplifier, limiter Q151 and discriminator 4 provide an output to turn on Q153 and stop the charge of the capacitor C179 so as to hold the receiver tuned to the received signal. To restart signal seeking a touch sensitive switch (12), Fig. 1 (not shown) is touched so as to operate transistors Q045, Q046, Fig. 4 to provide a signal at b. This block Q153 so as to commence sweeping of the generator 1. Also the signal at b makes Q161 conduct to discharge C178. Transistor Q161 conducts to make i negative until C178 has charged after 3 sec when Q160 turns off. This automatic time switch 7 acts to keep the receiver tuned to a detected station even if the sound carrier of the detected station fades. Also a memory circuit 13 acts to prevent loss of the channel to which the receiver is tuned to due to temporary loss of the video carrier since loss of the video carrier causes Q163 to conduct and Q164 to block so as to prevent charging of the sweep capacitor C179. A local distant switch (14), Fig. 1, (not shown) may be switched so as to connect the output from a current generator 10 to the AGC system of the receiver so as to obtain a decrease of gain of the RF stage when a signal sweep is made. A channel indicator (3) may be connected to the band switching circuit (2), Fig. 3, and to the tuning voltage from the sweep generator 1.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR7218291A FR2185906B1 (en) | 1972-05-23 | 1972-05-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1395919A true GB1395919A (en) | 1975-05-29 |
Family
ID=9098926
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2408972A Expired GB1395919A (en) | 1972-05-23 | 1972-05-23 | Device for automatic tuning of television receivers |
Country Status (3)
Country | Link |
---|---|
CH (1) | CH532874A (en) |
FR (1) | FR2185906B1 (en) |
GB (1) | GB1395919A (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1536040A (en) * | 1975-12-26 | 1978-12-20 | Sony Corp | Automatic fine tuning circuit |
US5161019A (en) * | 1990-06-29 | 1992-11-03 | Rca Thomson Licensing Corporation | "channel guide" automatically activated by the absence of program information |
US6560461B1 (en) | 1997-08-04 | 2003-05-06 | Mundi Fomukong | Authorized location reporting paging system |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1281501B (en) * | 1967-08-31 | 1968-10-31 | Blaupunkt Werke Gmbh | Overlay receiver with an electronic automatic station search |
FR1585641A (en) * | 1968-08-06 | 1970-01-30 | ||
NL149043B (en) * | 1968-12-20 | 1976-03-15 | Matsushita Electric Ind Co Ltd | AUTOMATIC TUNING DEVICE FOR A TELEVISION RECEIVER. |
-
1972
- 1972-05-23 FR FR7218291A patent/FR2185906B1/fr not_active Expired
- 1972-05-23 GB GB2408972A patent/GB1395919A/en not_active Expired
- 1972-06-07 CH CH845172A patent/CH532874A/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
FR2185906A1 (en) | 1974-01-04 |
FR2185906B1 (en) | 1977-05-06 |
CH532874A (en) | 1973-01-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5294915A (en) | Means for locating a remote control device | |
US4280139A (en) | Muting circuit for a television receiver | |
US3632864A (en) | Signal seeking system for radio receivers with tuning indicating circuitry for controlling the signal seeking | |
US3825838A (en) | Search tune detector circuit | |
GB1483626A (en) | Broadcast receiver tuning circuit | |
US3651411A (en) | Automatic-recycling signal-seeking voltage-controlled tuner | |
US3980968A (en) | Non-proportionate AFC system | |
US3631349A (en) | Automatic signal-seeking circuitry | |
US3610817A (en) | Television signal seeking system with horizontal synchronizing pulse detector circuit for controlling the signal seeking | |
GB1395919A (en) | Device for automatic tuning of television receivers | |
US3388215A (en) | Search tune system for television receivers | |
US3714580A (en) | Electronic search tuning system | |
GB753030A (en) | Improvements in sound television receivers | |
GB1536040A (en) | Automatic fine tuning circuit | |
US4159487A (en) | Low cost memory station | |
GB1429965A (en) | Broadcast receiver including an automatic frequency control circuit | |
US4348770A (en) | Manual channel selection apparatus | |
US3643167A (en) | Automatic turnoff system for receiver with fm demodulator | |
EP0052289A2 (en) | Voltage follower amplifier | |
US3968442A (en) | Receiver tuning circuit | |
US3611155A (en) | Search-tuning system sensitive to a dc voltage change | |
US3568065A (en) | Signal seeking scanning communication receiver with lower gain during scanning | |
US3478270A (en) | Automatic programming for detent-type tv tuner | |
US3706016A (en) | Motor control circuit | |
GB925157A (en) | Circuit arrangement for effecting automatic frequency readjustment in television receivers |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |