US2226259A - Amplifier - Google Patents
Amplifier Download PDFInfo
- Publication number
- US2226259A US2226259A US222810A US22281038A US2226259A US 2226259 A US2226259 A US 2226259A US 222810 A US222810 A US 222810A US 22281038 A US22281038 A US 22281038A US 2226259 A US2226259 A US 2226259A
- Authority
- US
- United States
- Prior art keywords
- cathode
- voltage
- resistance
- potentiometer
- tube
- 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 - Lifetime
Links
- 239000004020 conductor Substances 0.000 description 7
- 230000010355 oscillation Effects 0.000 description 5
- 238000012216 screening Methods 0.000 description 2
Images
Classifications
-
- 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
- H03F1/08—Modifications of amplifiers to reduce detrimental influences of internal impedances of amplifying elements
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/02—Manually-operated control
- H03G3/14—Manually-operated control in frequency-selective amplifiers
- H03G3/16—Manually-operated control in frequency-selective amplifiers having discharge tubes
-
- 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
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
- H04B1/1018—Means associated with receiver for limiting or suppressing noise or interference noise filters connected between the power supply and the receiver
Definitions
- Such a circuit arrangement is preferably utilized in a television receiver since in this case it is frequently impossible to provide in that porl tion of the cathode lead which is common to the grid circuit and to the anode circuit, a resistance component which determines the average brightr ness of the received image and of which it is undesired to be sup-plied to the grid of the high 25 or intermediate frequency amplifying tubes.
- an improvement in the circuit arrangement with which the invention is concerned is obtained by providing filters which suppress the high or intermediate frequen- 30 cy oscillations in the conductors by means of which the grid and the cathode of the tube or tubes to be controlled are connected to the potentiometer resistance from which the variable grid bias is taken.
- Fig. 1 represents a circuit arrangement with which the invention is concerned.
- Fig. 2 represents one mode of realization of a high or intermediate frequency amplifier according to the invention.
- the circuit arrangement shown in Fig. 1 com prises a high frequency amplifying tube l to the input circuit 2 of which the high frequency oscillations received in an aerial 3 are supplied and the output circuit of which includes an impedance 4 from which the oscillations amplified by the tube 1 are taken.
- the anode voltage ofv the tube l is determined by the drop of voltage in a resistance 5 across which occurs part of the voltage of a source of voltage 6, which part is determined by the ratio between the resistances 5 and 1.
- the grid bias of the tube l is taken from a potentiometer resistance 8 which is connected in j 5 parallel with that part of the source of voltage -6 which is determined by the value of the resistance 1.
- decoupling condensers 9 and l 0 are provided which bridge the resistances 8 and 1 respectively for the oscillations to be 10 amplified while a condenser II is connected in parallel with the source of voltage 6.
- the above described circuit arrangement has the drawback that for the oscillations to be amplified the condensersli: and I0 do not form complete short circuit but that due to the dielectric losses in these condensers and to the selfinductance of the connecting wires, high frequency voltages are set up between the points denoted by l2. and I3 and the earth. These voltages may be capacitativelytransmitted to the aerial 3, which gives rise to an undesired feedback.
- This drawback arises in particular if the ampliher is constructed as shown in Fig. 2 wherein the volume control of the apparatus can be efiected from a distance.
- the conductors by means of which 40 the grid and the cathode of the tube l are connected to the potentiometer resistance 8 have connected to them screen resistances l8 and I9 of which the screening member is earthed.
- resistance I9 is provided in the conductor connecting the cathode to the potentiometer resistance 8 in such manner that the anode direct current does not pass through this resistance.
- a tuned resonant circuit connected between the control electrode and cathode, a potentiometer having two end terminals and a tapped terminal included in the connection of the tuned resonant circuit to the cathode, a first shielded resistor' connected from the tuned resonant circuit to said tapped terminal of the potentiometer, a second shielded resistor connected to the cathode and one of said end terminals of the potentiometer, a source of voltage for supplying energy to the anode of the tube, a voltage divider connected across the source of voltage, and connections from said second shielded resistor to a portion of the voltage divider.
- a radio frequency amplifier comprising a thermionic tube having an anode, control electrode and cathode, a source of voltage for supplying said another with power, volume control means comprising a. potentiometer connected in parallel with at least a portion of said source of voltage, and low pass filters connected between said potentiometer and said control electrode and between'said potentiometer and said cathode for suppressing radio frequency components.
- a radio frequency amplifier comprising a thermionic tube having an anode, control electrode and cathode, a tuned resonant circuit connected between the control electrode and cathode, a source of voltage for supplying said anode with power, volume control means comtween said potentiometer and said cathode for suppressing radio frequency components.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Particle Accelerators (AREA)
- Microwave Tubes (AREA)
- Microwave Amplifiers (AREA)
Description
Dec. 24, 1940.
c. L. RICHARDS ET AL AMPLIFIER Filed Aug. 3, 1938 hu-M luvsN'r-oni CLAUDE LANGDON R/CHA 0S FEEDER/K KERKHOF Patented Dec. 24, 1940 UNITED" STATES PATENT OFFICE" AMPLIFIER Claude Langdon Richards and Frederik Kerkhof, Eindhoven, Netherlands, assignors, by mesne' assignments, to Radio Corporation of America, New York, N. Y., a corporation of Delaware Application August a, 1938, scrim No. 222,810 In the Netherlands August 25, 1937 4 Claims.
Such a circuit arrangement is preferably utilized in a television receiver since in this case it is frequently impossible to provide in that porl tion of the cathode lead which is common to the grid circuit and to the anode circuit, a resistance component which determines the average brightr ness of the received image and of which it is undesired to be sup-plied to the grid of the high 25 or intermediate frequency amplifying tubes.
According to the invention, an improvement in the circuit arrangement with which the invention is concerned, is obtained by providing filters which suppress the high or intermediate frequen- 30 cy oscillations in the conductors by means of which the grid and the cathode of the tube or tubes to be controlled are connected to the potentiometer resistance from which the variable grid bias is taken.
35 The conductors by means of which the grid and the cathode are connected to the potentiometer resistance preferably have connected in them screened resistances the screening of which is earthed.
40 The invention will be explained more fully with reference to the accompanying drawing wherein:
Fig. 1 represents a circuit arrangement with which the invention is concerned.
45 Fig. 2 represents one mode of realization of a high or intermediate frequency amplifier according to the invention. v
The circuit arrangement shown in Fig. 1 com prises a high frequency amplifying tube l to the input circuit 2 of which the high frequency oscillations received in an aerial 3 are supplied and the output circuit of which includes an impedance 4 from which the oscillations amplified by the tube 1 are taken. The anode voltage ofv the tube l is determined by the drop of voltage in a resistance 5 across which occurs part of the voltage of a source of voltage 6, which part is determined by the ratio between the resistances 5 and 1. The grid bias of the tube l is taken from a potentiometer resistance 8 which is connected in j 5 parallel with that part of the source of voltage -6 which is determined by the value of the resistance 1. Furthermore, decoupling condensers 9 and l 0 are provided which bridge the resistances 8 and 1 respectively for the oscillations to be 10 amplified while a condenser II is connected in parallel with the source of voltage 6.
"The above described circuit arrangement has the drawback that for the oscillations to be amplified the condensersli: and I0 do not form complete short circuit but that due to the dielectric losses in these condensers and to the selfinductance of the connecting wires, high frequency voltages are set up between the points denoted by l2. and I3 and the earth. These voltages may be capacitativelytransmitted to the aerial 3, which gives rise to an undesired feedback. This drawback arises in particular if the ampliher is constructed as shown in Fig. 2 wherein the volume control of the apparatus can be efiected from a distance.
In the embodiment shown in Fig. 2 the ends of the resistance 8 are connected by means of conductors l4 and Hi to the amplifier proper, the
point l2 being connected through the intermediary of a conductor H to a slide contact l6 on the resistance 8. Since the conductors l5 and I1 are capacitatively coupled with the aerial 3, there exists with this circuit arrangement a very great possibility that a high frequency voltage set up between the points I2 and l 3 and the earth is supplied via the aerial 3 to the grid of the tube I.
According to the invention, in order to remove this drawback the conductors by means of which 40 the grid and the cathode of the tube l are connected to the potentiometer resistance 8 have connected to them screen resistances l8 and I9 of which the screening member is earthed. These resistances'act as filters which suppress the high frequency voltages set up between the points I2 and I3 and the earth, owing to which it is achieved that between the terminal points and the slide contact l6 of the resistance 8 and the earth there is no high frequency voltage. The
resistance I9 is provided in the conductor connecting the cathode to the potentiometer resistance 8 in such manner that the anode direct current does not pass through this resistance. A further advantage of the circuit arrange- 1. An amplifier comprising a thermionic tube having an anode, control electrode and. cathode, a tuned resonant circuit connected between the control electrode and cathode, a potentiometer having two end terminals and a tapped terminal included in the connection of the tuned resonant circuit to the cathode, a first shielded resistor' connected from the tuned resonant circuit to said tapped terminal of the potentiometer, a second shielded resistor connected to the cathode and one of said end terminals of the potentiometer, a source of voltage for supplying energy to the anode of the tube, a voltage divider connected across the source of voltage, and connections from said second shielded resistor to a portion of the voltage divider.
2. A radio frequency amplifier comprising a thermionic tube having an anode, control electrode and cathode, a source of voltage for supplying said another with power, volume control means comprising a. potentiometer connected in parallel with at least a portion of said source of voltage, and low pass filters connected between said potentiometer and said control electrode and between'said potentiometer and said cathode for suppressing radio frequency components.
3. A radio frequency amplifier as claimed in claim 2 wherein said low pass filters comprise shielded resistances, the shields of said resistances being grounded.
4. A radio frequency amplifier comprising a thermionic tube having an anode, control electrode and cathode, a tuned resonant circuit connected between the control electrode and cathode, a source of voltage for supplying said anode with power, volume control means comtween said potentiometer and said cathode for suppressing radio frequency components.
. CLAUDE LANGDON RICHARDS.
FREDERIK KERKHOF.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL2226259X | 1937-08-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2226259A true US2226259A (en) | 1940-12-24 |
Family
ID=19873916
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US222810A Expired - Lifetime US2226259A (en) | 1937-08-25 | 1938-08-03 | Amplifier |
Country Status (1)
Country | Link |
---|---|
US (1) | US2226259A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2522967A (en) * | 1948-05-21 | 1950-09-19 | Rca Corp | Video amplifier feeding constant black level output to cathoderay tube |
US2644083A (en) * | 1945-02-27 | 1953-06-30 | Us Sec War | Instantaneous automatic gain control circuit |
US2708687A (en) * | 1949-05-10 | 1955-05-17 | Motorola Inc | Combined direct current reinserter and synchronizing pulse separator |
US3069626A (en) * | 1957-06-24 | 1962-12-18 | Clevite Corp | Reflex amplifier circuit with volume control means |
US3109047A (en) * | 1960-04-01 | 1963-10-29 | Jr Melville Clark | Intensity rate of change control for musical instruments |
-
1938
- 1938-08-03 US US222810A patent/US2226259A/en not_active Expired - Lifetime
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2644083A (en) * | 1945-02-27 | 1953-06-30 | Us Sec War | Instantaneous automatic gain control circuit |
US2522967A (en) * | 1948-05-21 | 1950-09-19 | Rca Corp | Video amplifier feeding constant black level output to cathoderay tube |
US2708687A (en) * | 1949-05-10 | 1955-05-17 | Motorola Inc | Combined direct current reinserter and synchronizing pulse separator |
US3069626A (en) * | 1957-06-24 | 1962-12-18 | Clevite Corp | Reflex amplifier circuit with volume control means |
US3109047A (en) * | 1960-04-01 | 1963-10-29 | Jr Melville Clark | Intensity rate of change control for musical instruments |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2185367A (en) | Thermionic valve amplifying circuit | |
US2143671A (en) | Ultra short wave circuit | |
US2324279A (en) | Amplifier | |
US2226259A (en) | Amplifier | |
US2670408A (en) | Coupling stage for distributed amplifier stages | |
US1968610A (en) | Thermionic amplifying system | |
US2253849A (en) | Short wave radio apparatus | |
US2358325A (en) | Gain control circuits | |
US2226255A (en) | Thermionic valve circuit | |
US2444864A (en) | High-frequency tuned amplifying circuit | |
US2061733A (en) | Thermionic device | |
US2058738A (en) | Electrical circuit for cold cathode tubes | |
US1904524A (en) | Amplifier | |
US2427241A (en) | Push-pull circuit arrangement for ultra-short waves | |
US2398502A (en) | Oscillation generation | |
US2077126A (en) | Volume control arrangement | |
US2017020A (en) | Negative bias for audio frequency amplifiers | |
US2261787A (en) | Amplifier | |
US2250206A (en) | Amplifying system | |
US1863798A (en) | Circuit arrangement for transmitter tubes | |
US2139366A (en) | Electron discharge device | |
US2527737A (en) | Variable frequency band width amplifier | |
US2045316A (en) | Impedance coupled amplifier | |
US2094477A (en) | Circuit arrangement for amplifying and/or frequency transformation of electrical oscillations | |
US2335050A (en) | Electron discharge amplifier |