GB768987A - Improvements in or relating to transistor amplifiers - Google Patents
Improvements in or relating to transistor amplifiersInfo
- Publication number
- GB768987A GB768987A GB13191/55A GB1319155A GB768987A GB 768987 A GB768987 A GB 768987A GB 13191/55 A GB13191/55 A GB 13191/55A GB 1319155 A GB1319155 A GB 1319155A GB 768987 A GB768987 A GB 768987A
- Authority
- GB
- United Kingdom
- Prior art keywords
- transistor
- circuit
- impedance
- selectivity
- fed
- 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
- 239000003990 capacitor Substances 0.000 abstract 2
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
-
- 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
- H03G1/0017—Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal the device being at least one of the amplifying solid state elements of the amplifier
-
- 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
- H03G9/20—Combinations of two or more types of control, e.g. gain control and tone control in frequency-selective amplifiers
- H03G9/24—Combinations of two or more types of control, e.g. gain control and tone control in frequency-selective amplifiers having semiconductor devices
Landscapes
- Amplifiers (AREA)
Abstract
768,987. Transistor gain control circuits. 'PHILIPS ELECTRICAL INDUSTRIES, Ltd. May 6, 1955 [May 11, 1954], No. 13191/55. Class 40(6) In a circuit controlled by a variable current i, the inductor 7 and capacitor 8, Fig. 2, form a series circuit with the input impedance of the transistor 2. An impedance 9 having a value lying between the minimum and maximum of the transistor input impedance shunts the transistor to reduce variations in selectivity with varying control current. By employing a large capacitor 6 the effective impedance between'emitter and base is resistive. In a modification, Fig. 3, the resistor 9 is made of greater value to reduce the loss in gain the circuit being fed from an earlier stage 12. The transistor 12 is connected to a parallel resonant circuit 1, the selectivity of which will vary in the opposite manner from that of circuit 7, 8. The control current i is 'applied to transistor 12 and an amplified version is fed to the emitter circuit of transistor 2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL331070X | 1954-05-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB768987A true GB768987A (en) | 1957-02-27 |
Family
ID=19784372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB13191/55A Expired GB768987A (en) | 1954-05-11 | 1955-05-06 | Improvements in or relating to transistor amplifiers |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE538059A (en) |
| CH (1) | CH331070A (en) |
| DE (1) | DE969352C (en) |
| GB (1) | GB768987A (en) |
| NL (2) | NL187486B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1145236B (en) * | 1958-12-15 | 1963-03-14 | Telefunken Patent | Circuit arrangement for the automatic gain control of high or intermediate frequency amplifiers with transistors above a threshold value |
| DE1267286B (en) * | 1959-03-05 | 1968-05-02 | Philips Nv | Receive circuit with gain control |
| DE1204286B (en) * | 1961-03-23 | 1965-11-04 | Telefunken Patent | Selective controllable transistor amplifier |
| DE2259675C2 (en) * | 1972-12-06 | 1982-03-04 | Robert Bosch Gmbh, 7000 Stuttgart | High frequency amplifier |
-
0
- BE BE538059D patent/BE538059A/xx unknown
- NL NL85795D patent/NL85795C/xx active
- NL NLAANVRAGE8700830,A patent/NL187486B/en unknown
-
1955
- 1955-05-06 GB GB13191/55A patent/GB768987A/en not_active Expired
- 1955-05-08 DE DEN10618A patent/DE969352C/en not_active Expired
- 1955-05-09 CH CH331070D patent/CH331070A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE969352C (en) | 1958-05-22 |
| CH331070A (en) | 1958-06-30 |
| NL85795C (en) | |
| NL187486B (en) | |
| BE538059A (en) |
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