GB636101A - Improvements in and apparatus for converting recorded sound waves to frequency-modulated currents - Google Patents
Improvements in and apparatus for converting recorded sound waves to frequency-modulated currentsInfo
- Publication number
- GB636101A GB636101A GB4185/44A GB418544A GB636101A GB 636101 A GB636101 A GB 636101A GB 4185/44 A GB4185/44 A GB 4185/44A GB 418544 A GB418544 A GB 418544A GB 636101 A GB636101 A GB 636101A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequencies
- frequency
- capacities
- output
- march
- 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
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/06—Gramophone pick-ups using a stylus; Recorders using a stylus
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/10—Angle modulation by means of variable impedance
- H03C3/28—Angle modulation by means of variable impedance using variable impedance driven mechanically or acoustically
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/04—Microphones
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Electrophonic Musical Instruments (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
Abstract
636,101. Frequency-modulation. BRITISH THOMSON-HOUSTON CO., Ltd. March 7, 1944, No. 4185. Convention date, March 9, 1943. [Class 40 (v)] [Also in Group XXXIX] In a circuit for deriving a frequency-modulated output from an electrostatic gramophone pick-up, capacities 65, 66 varied by an electrode 10 vibrated between relatively fixed electrodes 11, 12 are included in oscillating circuits having different frequencies and comprising valves 40, 41, inductances 42, 43, capacity 44, grid resistances 47 and grid byepass capacities 48. The greater frequency is arranged to be less than twice the smaller frequency and the valve circuits are maintained in oscillation by feed-back through resistances 45, 46. The output taken from the mid-point of the output resistance 54 of the valves 40, 41 is fed to a detector diode 56, whose output at resistance 57 includes voltages of frequencies corresponding to the frequencies of the oscillators and also corresponding to the sum and difference of these frequencies. A filter circuit 62, 63, 64 removes all frequencies except the difference frequencies corresponding to the push-pull variation of the capacities 65, 66. Additional tuning capacitors 67, 68 which are preferably adjustable, may be utilized to reduce or compensate for, harmonic distortion.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US478565A US2386049A (en) | 1943-03-09 | 1943-03-09 | Apparatus for converting sound to frequency modulated currents |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB636101A true GB636101A (en) | 1950-04-26 |
Family
ID=23900441
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB4185/44A Expired GB636101A (en) | 1943-03-09 | 1944-03-07 | Improvements in and apparatus for converting recorded sound waves to frequency-modulated currents |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2386049A (en) |
| GB (1) | GB636101A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2445990A (en) * | 1943-06-12 | 1948-07-27 | Rca Corp | Signal translating apparatus |
| US2423208A (en) * | 1944-05-30 | 1947-07-01 | Rca Corp | Electrostatic pickup |
| US2559454A (en) * | 1945-07-18 | 1951-07-03 | Stewart Warner Corp | Capacitor type translating system having a varying reactance |
| US2515791A (en) * | 1945-12-15 | 1950-07-18 | Colonial Radio Corp | Circuit for capacity microphones or pickups |
| US2532060A (en) * | 1946-05-27 | 1950-11-28 | Robert H Dicke | Electrostatic vibration detector |
| US2522870A (en) * | 1946-09-30 | 1950-09-19 | Bendix Aviat Corp | Phonograph pickup system |
| US2589091A (en) * | 1948-10-15 | 1952-03-11 | Rca Corp | Mechanical modulator |
| US2655630A (en) * | 1949-01-29 | 1953-10-13 | A V Roe Canada Ltd | Electronic control for contour milling machines |
| US2641741A (en) * | 1949-02-21 | 1953-06-09 | Phillips Petroleum Co | Crystal controlled modulated oscillator |
| NL160670B (en) * | 1950-04-22 | Thomson Houston Comp Francaise | PROCEDURE FOR THE MANUFACTURE OF A MULTI-WIRE SUPER-CONDUCTIVE CABLE, AND CABLE MANUFACTURED ACCORDING TO THIS PROCESS. | |
| US3239803A (en) * | 1957-06-10 | 1966-03-08 | Atlantic Refining Co | Variable capacitance geophone assembly for seismic prospecting |
-
1943
- 1943-03-09 US US478565A patent/US2386049A/en not_active Expired - Lifetime
-
1944
- 1944-03-07 GB GB4185/44A patent/GB636101A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US2386049A (en) | 1945-10-02 |
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