GB378539A - Improvements in or relating to audio frequency amplifier arrangements - Google Patents
Improvements in or relating to audio frequency amplifier arrangementsInfo
- Publication number
- GB378539A GB378539A GB12661/31A GB1266131A GB378539A GB 378539 A GB378539 A GB 378539A GB 12661/31 A GB12661/31 A GB 12661/31A GB 1266131 A GB1266131 A GB 1266131A GB 378539 A GB378539 A GB 378539A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- audio frequency
- resistance
- gain
- low
- 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
- 230000003247 decreasing effect Effects 0.000 abstract 2
- 230000004048 modification Effects 0.000 abstract 2
- 238000012986 modification Methods 0.000 abstract 2
- 230000003321 amplification Effects 0.000 abstract 1
- 238000013459 approach Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 abstract 1
- 238000003199 nucleic acid amplification method Methods 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G9/00—Combinations of two or more types of control, e.g. gain control and tone control
- H03G9/02—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers
- H03G9/04—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers having discharge tubes
- H03G9/10—Combinations of two or more types of control, e.g. gain control and tone control in untuned amplifiers having discharge tubes for tone control and volume expansion or compression
Landscapes
- Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
- Control Of Amplification And Gain Control (AREA)
Abstract
378,539. Valve amplifying circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Marconi House, Strand, London.- (Assignees of Roberts, W. van B. ; 155, Hodge Road, Princetown, New Jersey, U.S.A.) April 29, 1931, No. 12661. Convention date, April 29, 1930. [Class 40 (v).] In an audio frequency amplifier means are provided to control automatically the amplification and also the ratio of high to low frequency in accordance with the input. The Figure shows a three stage amplifier 62, 70, 81 in which the low note response is decreased with increase in input by decreasing the bias of valve 62 so that the choke L approaches saturation. The gain is simultaneously increased by increasing the screen grid voltage of valve 70. The voltage variations are effected by resistance 53 through which amplified, rectified and smoothed current from the input passes. Alternatively the pilot amplifier C is dispensed with and the voltage variations to effect the control are taken from resistance 76<1> instead of resistance 53. In a modification, Fig. 2 (not shown), separate amplifiers are used for the high and low frequencies and have different degrees of control applied to them by variation of the screen grid voltage of amplifying valves. In a further modification, Fig. 3 (not shown) a screen-grid valve is transformer coupled to the following amplifying valve and is shunted by a triode. The bias of this valve is controlled by the signal strength so that its impedance is reduced with low inputs thus reducing the gain and particularly the high audio frequency gain.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US378539XA | 1930-04-29 | 1930-04-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB378539A true GB378539A (en) | 1932-08-18 |
Family
ID=21896729
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB12661/31A Expired GB378539A (en) | 1930-04-29 | 1931-04-29 | Improvements in or relating to audio frequency amplifier arrangements |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB378539A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE754915C (en) * | 1934-08-04 | 1953-02-23 | Hazeltine Corp | Circuit for amplifying electrical vibrations, especially for low frequency amplification |
| DE881058C (en) * | 1938-05-19 | 1953-06-25 | Western Electric Co | Arrangement for reducing the distortion in character transmission systems |
-
1931
- 1931-04-29 GB GB12661/31A patent/GB378539A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE754915C (en) * | 1934-08-04 | 1953-02-23 | Hazeltine Corp | Circuit for amplifying electrical vibrations, especially for low frequency amplification |
| DE881058C (en) * | 1938-05-19 | 1953-06-25 | Western Electric Co | Arrangement for reducing the distortion in character transmission systems |
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