GB580815A - Improvements in or relating to piezo-electric crystal discriminator circuits - Google Patents
Improvements in or relating to piezo-electric crystal discriminator circuitsInfo
- Publication number
- GB580815A GB580815A GB2854/44A GB285444A GB580815A GB 580815 A GB580815 A GB 580815A GB 2854/44 A GB2854/44 A GB 2854/44A GB 285444 A GB285444 A GB 285444A GB 580815 A GB580815 A GB 580815A
- Authority
- GB
- United Kingdom
- Prior art keywords
- condenser
- coil
- crystal
- centre
- neutralizing
- 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
- 239000013078 crystal Substances 0.000 title abstract 7
- 230000003472 neutralizing effect Effects 0.000 abstract 4
- 238000006386 neutralization reaction Methods 0.000 abstract 3
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
- H03J7/02—Automatic frequency control
- H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
- H03D3/00—Demodulation of angle-, frequency- or phase- modulated oscillations
- H03D3/02—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal
- H03D3/06—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators
- H03D3/16—Demodulation of angle-, frequency- or phase- modulated oscillations by detecting phase difference between two signals obtained from input signal by combining signals additively or in product demodulators by means of electromechanical resonators
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
- H03H9/545—Filters comprising resonators of piezoelectric or electrostrictive material including active elements
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Oscillators With Electromechanical Resonators (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
580,815. Phase modulation; automatic tuning correction. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 16, 1944, No. 2854. Convention date, Feb. 16, 1943. [Class 40 (v)] In a piezo-electric crystal discriminator circuit employing a condenser for neutralizing the capacity of the crystal holder, further condensers are provided connected respectively in shunt to the crystal and to the neutralizing condenser to afford under-neutralization and over-neutralization characteristics at the inputs to a pair of opposed rectifiers. Fig. 1 shows a phase-modulation receiver in which IF carrier is fed to a pentode valve 1 having a tuned anode circuit coupled to a centre-tapped coil 7, one end of which is connected to the crystal P and the other to a neutralizing condenser 13. The other terminals of the crystal P and condenser 13 are connected to each other and through isolating condensers 9, 9<1> to the anodes of rectifiers A, B. The ends of the coil 7 are also connected to the rectifier anodes through an under-neutralization condenser 21 and an overneutralization condenser 22. The rectifiers are shunted by resistances 19, 20 and are in series with resistances 14, 15 the respective junctions being connected to the centre tap of the coil 7. One rectifier cathode B is earthed, and the voltage taken from the other cathode contains both the detected PM signal, and a slowlyvarying component for use in tuning the local oscillator. The anode of rectifier A supplies a voltage representing any amplitude modulation of the carrier. The centre-tapped coil 7 may be connected as a tuned coil in the anode circuit of the valve 1 (Fig. 4, not shown). In Fig. 5, the tuned anode coil 4 is connected to one end of the centre-tapped coil 30 by the crystal P, and to the other end by the neutralizing condenser 13. The isolating condensers 9, 9<1> and the under- and over-neutralizing condensers 21, 22 are connected similarly to Fig. 1. The centre-tapped coil 30 is tuned by the condenser 31 to one side or the other of the carrier frequency. U.S.A. Specification 2,204,575 is referred to.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US476052A US2397840A (en) | 1943-02-16 | 1943-02-16 | Phase modulation detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB580815A true GB580815A (en) | 1946-09-20 |
Family
ID=23890305
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2854/44A Expired GB580815A (en) | 1943-02-16 | 1944-02-16 | Improvements in or relating to piezo-electric crystal discriminator circuits |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2397840A (en) |
| GB (1) | GB580815A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB569339A (en) * | 1941-12-19 | 1945-05-18 | British Thomson Houston Co Ltd | Circuit arrangement for producing trains of sinusoidal oscillations |
| US2561149A (en) * | 1945-09-10 | 1951-07-17 | Rca Corp | Frequency modulation detector circuits |
| US2540512A (en) * | 1946-07-27 | 1951-02-06 | Rca Corp | Interference reducing impulse amplitude detector |
| US2461956A (en) * | 1946-10-10 | 1949-02-15 | Gen Electric | Frequency response circuits |
| US2630558A (en) * | 1948-04-29 | 1953-03-03 | Rca Corp | Improvement in balanced phase splitting network |
| US2702343A (en) * | 1949-01-06 | 1955-02-15 | Rca Corp | Piezoelectric crystal filter for exalted carrier and discriminator circuits |
| US2724089A (en) * | 1949-12-09 | 1955-11-15 | Du Mont Allen B Lab Inc | Crystal discriminator |
| US2772378A (en) * | 1951-12-11 | 1956-11-27 | United Aircraft Corp | Speed control circuits |
| CA578158A (en) * | 1953-04-21 | 1959-06-23 | Westinghouse Electric Corporation | Frequency shift receiver |
| US3122707A (en) * | 1957-06-10 | 1964-02-25 | Atlantic Refining Co | Discriminator for frequency modulated seismic signals |
-
1943
- 1943-02-16 US US476052A patent/US2397840A/en not_active Expired - Lifetime
-
1944
- 1944-02-16 GB GB2854/44A patent/GB580815A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US2397840A (en) | 1946-04-02 |
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