GB1196647A - Recording and/or Playback Apparatus - Google Patents

Recording and/or Playback Apparatus

Info

Publication number
GB1196647A
GB1196647A GB4439667A GB4439667A GB1196647A GB 1196647 A GB1196647 A GB 1196647A GB 4439667 A GB4439667 A GB 4439667A GB 4439667 A GB4439667 A GB 4439667A GB 1196647 A GB1196647 A GB 1196647A
Authority
GB
United Kingdom
Prior art keywords
filter
lamp
signal level
recording
amplifier
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
Application number
GB4439667A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
PHILLIPS ELECTRONIC AND ASSOCI
Original Assignee
PHILLIPS ELECTRONIC AND ASSOCI
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by PHILLIPS ELECTRONIC AND ASSOCI filed Critical PHILLIPS ELECTRONIC AND ASSOCI
Publication of GB1196647A publication Critical patent/GB1196647A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G1/00—Details of arrangements for controlling amplification
    • H03G1/0005—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal
    • H03G1/0035—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements
    • H03G1/0047—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal using continuously variable impedance elements using photo-electric elements
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
    • G11B23/0007—Circuits or methods for reducing noise, for correction of distortion, or for changing density of recorded information
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/16—Automatic control
    • H03G5/18—Automatic control in untuned amplifiers
    • H03G5/22—Automatic control in untuned amplifiers having semiconductor devices
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H11/00—Networks using active elements
    • H03H11/02—Multiple-port networks
    • H03H11/04—Frequency selective two-port networks
    • H03H11/0405—Non-linear filters

Abstract

1,196,647. Automatic volume and tone concontrol. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 29 Sept., 1967 [4 Oct., 1966], No. 44396/67. Heading H4R. A recording and/or playback amplifier Fig. 4 includes a low pass filter 12 having a circuit element, e.g. lamp 18, whose impedance depends on signal level so that the cut off frequency of the filter is reduced as the signal level reduces, to reduce the disturbing effects of high frequency noise components. The filter may alternatively be formed by a series negative temperature coefficient resistor and a shunt capacitor. As shown the lamp 18 is also used to provide automatic gain control by varying the resistance of the photo sensitive resistor 20 in the negative feedback path 19 of the amplifier.
GB4439667A 1966-10-04 1967-09-29 Recording and/or Playback Apparatus Expired GB1196647A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEN0029282 1966-10-04

Publications (1)

Publication Number Publication Date
GB1196647A true GB1196647A (en) 1970-07-01

Family

ID=7345030

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4439667A Expired GB1196647A (en) 1966-10-04 1967-09-29 Recording and/or Playback Apparatus

Country Status (7)

Country Link
BE (1) BE704624A (en)
CH (1) CH464558A (en)
DE (1) DE1499809A1 (en)
ES (1) ES345668A1 (en)
GB (1) GB1196647A (en)
NL (1) NL6713244A (en)
SE (1) SE328712B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3798559A (en) * 1971-04-20 1974-03-19 Matsushita Electric Ind Co Ltd Noise reduction system

Also Published As

Publication number Publication date
ES345668A1 (en) 1968-11-16
CH464558A (en) 1968-10-31
NL6713244A (en) 1968-04-05
DE1499809A1 (en) 1970-02-19
BE704624A (en) 1968-04-03
SE328712B (en) 1970-09-21

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees