GB552331A - Improvements in or relating to thermionic amplifiers - Google Patents

Improvements in or relating to thermionic amplifiers

Info

Publication number
GB552331A
GB552331A GB16139/41A GB1613941A GB552331A GB 552331 A GB552331 A GB 552331A GB 16139/41 A GB16139/41 A GB 16139/41A GB 1613941 A GB1613941 A GB 1613941A GB 552331 A GB552331 A GB 552331A
Authority
GB
United Kingdom
Prior art keywords
resistance
valve
output
feedback
dec
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
GB16139/41A
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.)
AT&T Corp
Original Assignee
Western Electric Co Inc
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 Western Electric Co Inc filed Critical Western Electric Co Inc
Publication of GB552331A publication Critical patent/GB552331A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/1607—Supply circuits
    • H04B1/1623—Supply circuits using tubes
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
    • H03F1/36—Negative-feedback-circuit arrangements with or without positive feedback in discharge-tube amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers without distortion of the input signal
    • H03G3/02—Manually-operated control
    • H03G3/04—Manually-operated control in untuned amplifiers
    • H03G3/06—Manually-operated control in untuned amplifiers having discharge tubes
    • H03G3/08—Manually-operated control in untuned amplifiers having discharge tubes incorporating negative feedback
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception

Abstract

552,331. Hearing aids. WESTERN ELECTRIC CO., Inc. Dec. 15, 1941. No. 16139. Convention date, Dec. 24, 1940. [Class 40 (iv)] [Also in Group XL] A valve amplifier for portable use, such as a hearing aid, includes a degenerative feedback applied over a path used to supply the valves with high tension current and the gain is controlled by varying the feedback by means of a potentiometer connected across the output load. Fig. 1 shows a three-stage amplifier in which a path 21 conducts signal and direct currents from the anode of the output valve 15 to the output of a preceding valve 14 and to the screen 28 of a preceding valve 12. Positive feedback is produced by resistance 32 to compensate for the loss of gain due to battery resistance changes due to aging of the battery. Either a crystal-type receiver 44 or an electromagnetic receiver 17 may be used, a resistance 54 being provided to simulate the effect of a constant-K network in the former case and a limiting device 52 in the latter case to protect the user from acoustic shock. The limiter may be a thyrite resistance or a thermal device if more gradual limiting is required. The resistance capacity network 35-39 is provided together with the switch 40 to control the low frequency response to protect the valves against overloading in noisy locations.
GB16139/41A 1940-12-24 1941-12-15 Improvements in or relating to thermionic amplifiers Expired GB552331A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US371498A US2342822A (en) 1940-12-24 1940-12-24 Amplifying system

Publications (1)

Publication Number Publication Date
GB552331A true GB552331A (en) 1943-04-01

Family

ID=23464205

Family Applications (1)

Application Number Title Priority Date Filing Date
GB16139/41A Expired GB552331A (en) 1940-12-24 1941-12-15 Improvements in or relating to thermionic amplifiers

Country Status (5)

Country Link
US (1) US2342822A (en)
BE (1) BE471331A (en)
FR (1) FR942174A (en)
GB (1) GB552331A (en)
NL (1) NL68241C (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481533A (en) * 1944-06-06 1949-09-13 Rca Corp Audio amplifier circuits for radio transmitters
US2710721A (en) * 1945-11-27 1955-06-14 Amasa S Bishop Electronic dividing circuit
US2541811A (en) * 1947-10-10 1951-02-13 Joseph W Crownover Hearing aid amplifier
US2761918A (en) * 1952-11-19 1956-09-04 Dictograph Products Co Inc Amplifier with gain control and power control
WO2007009483A1 (en) * 2005-07-21 2007-01-25 Freescale Semiconductor, Inc. Microphone amplification arrangement and integrated circuit therefor

Also Published As

Publication number Publication date
FR942174A (en) 1949-02-01
NL68241C (en)
US2342822A (en) 1944-02-29
BE471331A (en)

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