Tubes. Behavioral Obpctives Are Listed. a 19-Item Bibliography of References and Films Is Included Together with a Posttest Sample
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Fundamentals of Microelectronics Chapter 3 Diode Circuits
9/17/2010 Fundamentals of Microelectronics CH1 Why Microelectronics? CH2 Basic Physics of Semiconductors CH3 Diode Circuits CH4 Physics of Bipolar Transistors CH5 Bipolar Amplifiers CH6 Physics of MOS Transistors CH7 CMOS Amplifiers CH8 Operational Amplifier As A Black Box 1 Chapter 3 Diode Circuits 3.1 Ideal Diode 3.2 PN Junction as a Diode 3.3 Applications of Diodes 2 1 9/17/2010 Diode Circuits After we have studied in detail the physics of a diode, it is time to study its behavior as a circuit element and its many applications. CH3 Diode Circuits 3 Diode’s Application: Cell Phone Charger An important application of diode is chargers. Diode acts as the black box (after transformer) that passes only the positive half of the stepped-down sinusoid. CH3 Diode Circuits 4 2 9/17/2010 Diode’s Action in The Black Box (Ideal Diode) The diode behaves as a short circuit during the positive half cycle (voltage across it tends to exceed zero), and an open circuit during the negative half cycle (voltage across it is less than zero). CH3 Diode Circuits 5 Ideal Diode In an ideal diode, if the voltage across it tends to exceed zero, current flows. It is analogous to a water pipe that allows water to flow in only one direction. CH3 Diode Circuits 6 3 9/17/2010 Diodes in Series Diodes cannot be connected in series randomly. For the circuits above, only a) can conduct current from A to C. CH3 Diode Circuits 7 IV Characteristics of an Ideal Diode V V R = 0⇒ I = = ∞ R = ∞⇒ I = = 0 R R If the voltage across anode and cathode is greater than zero, the resistance of an ideal diode is zero and current becomes infinite. -
El156 Audio Power
EL156 AUDIO POWER Gerhard Haas Thanks to its robustness, the legendary EL156 audio power pentode has found its way into many professional amplifier units. Its attraction derives not just from its appealing shape, but also from its impressive audio characteristics. We therefore bring you this classical circuit, updated using high- quality modern components. 28 elektor electronics - 3/2005 AMPLIFIER Return of a legend The EL156 was manufactured in the enough to give adequate sensitivity, electrolytic capacitor: this voltage is legendary Telefunken valve factory in even before allowing any margin for further filtered on the amplifier board. Ulm, near the river Danube in Ger- negative feedback. The ECC81 many. The EL156 made amplifiers with (12AT7), however, which has an open- It is not possible to build an ultra-lin- an output power of up to 130 W possi- loop gain of 60 and which can be oper- ear amplifier using the EL156 with a ble, using just two valves in the output ated with anode currents of up to high anode voltage. The same goes for stage and one driver valve. Genuine 10 mA, can be used to build a suitably the EL34. The output transformer is EL156s are no longer available new at low-impedance circuit. therefore connected in such a way that realistic prices, and hardly any are Two EL156s can be used to produce an the impedance of the grid connection available second-hand. The original output power of 130 W with only 6 % to the output valve is much lower than devices used a metal valve base which distortion. -
Vacuum Tube Theory, a Basics Tutorial – Page 1
Vacuum Tube Theory, a Basics Tutorial – Page 1 Vacuum Tubes or Thermionic Valves come in many forms including the Diode, Triode, Tetrode, Pentode, Heptode and many more. These tubes have been manufactured by the millions in years gone by and even today the basic technology finds applications in today's electronics scene. It was the vacuum tube that first opened the way to what we know as electronics today, enabling first rectifiers and then active devices to be made and used. Although Vacuum Tube technology may appear to be dated in the highly semiconductor orientated electronics industry, many Vacuum Tubes are still used today in applications ranging from vintage wireless sets to high power radio transmitters. Until recently the most widely used thermionic device was the Cathode Ray Tube that was still manufactured by the million for use in television sets, computer monitors, oscilloscopes and a variety of other electronic equipment. Concept of thermionic emission Thermionic basics The simplest form of vacuum tube is the Diode. It is ideal to use this as the first building block for explanations of the technology. It consists of two electrodes - a Cathode and an Anode held within an evacuated glass bulb, connections being made to them through the glass envelope. If a Cathode is heated, it is found that electrons from the Cathode become increasingly active and as the temperature increases they can actually leave the Cathode and enter the surrounding space. When an electron leaves the Cathode it leaves behind a positive charge, equal but opposite to that of the electron. In fact there are many millions of electrons leaving the Cathode. -
Diodes As Rectifiers +
Diodes as Rectifiers As previously mentioned, diodes can be used to convert alternating current (AC) to direct current (DC). Shown below is a representative schematic of a simple DC power supply similar to a au- tomobile battery charger. The way in which the diode rectifier is used results in what is called a half-wave rectifier. 0V 35.6Vpp 167V 0V pp 17.1Vp 0V T1 D1 Wallplug 1N4001 negative half−wave is 110VAC R1 resistive load removed by diode D1 D1 120 to 12.6VAC − stepdown transformer + D2 D2 input from RL input from RL transformer transformer (positive half−cycle) Figure 1: Half-Wave Rectifier Schematic (negative half−cycle) − D3 + D3 The input transformer steps the input voltage down from 110VAC(rms) to 12.6VAC(rms). The D4 D4 diode converts the AC voltage to DC by removing theD1 and negative D3 goingD1 and D3 part of the input sine wave. The result is a pulsating DC output waveform which is not ideal except for17.1V simplep applications 0V such as battery chargers as the voltage goes to zero for oneD2 have and D4 of every cycle. What we would D1 D1 v_out like is a DC output that is more consistent;T1 a waveform more like a battery what we have here. T1 1 D2 D2 C1 Wallplug R1 Wallplug R1 We need a way to use the negative half-cycle of theresistive sine load wave to to fill in between the pulses 50uF 1K 110VAC 110VAC created by the positive half-waves. This would give us a more consistent output voltage. -
Lecture 3: Diodes and Transistors
2.996/6.971 Biomedical Devices Design Laboratory Lecture 3: Diodes and Transistors Instructor: Hong Ma Sept. 17, 2007 Diode Behavior • Forward bias – Exponential behavior • Reverse bias I – Breakdown – Controlled breakdown Æ Zeners VZ = Zener knee voltage Compressed -VZ scale 0V 0.7 V V ⎛⎞V Breakdown V IV()= I et − 1 S ⎜⎟ ⎝⎠ kT V = t Q Types of Diode • Silicon diode (0.7V turn-on) • Schottky diode (0.3V turn-on) • LED (Light-Emitting Diode) (0.7-5V) • Photodiode • Zener • Transient Voltage Suppressor Silicon Diode • 0.7V turn-on • Important specs: – Maximum forward current – Reverse leakage current – Reverse breakdown voltage • Typical parts: Part # IF, max IR VR, max Cost 1N914 200mA 25nA at 20V 100 ~$0.007 1N4001 1A 5µA at 50V 50V ~$0.02 Schottky Diode • Metal-semiconductor junction • ~0.3V turn-on • Often used in power applications • Fast switching – no reverse recovery time • Limitation: reverse leakage current is higher – New SiC Schottky diodes have lower reverse leakage Reverse Recovery Time Test Jig Reverse Recovery Test Results • Device tested: 2N4004 diode Light Emitting Diode (LED) • Turn-on voltage from 0.7V to 5V • ~5 years ago: blue and white LEDs • Recently: high power LEDs for lighting • Need to limit current LEDs in Parallel V R ⎛⎞ Vt IV()= IS ⎜⎟ e − 1 VS = 3.3V ⎜⎟ ⎝⎠ •IS is strongly dependent on temp. • Resistance decreases R R R with increasing V = 3.3V S temperature • “Power Hogging” Photodiode • Photons generate electron-hole pairs • Apply reverse bias voltage to increase sensitivity • Key specifications: – Sensitivity -
Operation, Tetrode, Pentode in the Single-Ended, Class-A
10-76 10. Guitar Amplifiers 10.5.1 Single-ended (class A)-operation, tetrode, pentode In the single-ended, class-A power-stage, one (single) power-tube operates in common- cathode configuration with the output transformer being part of the plate circuit (transformer- coupling). Without AC-drive (“quiescent state”), a stable balance appears – it is called the operating point (OPP). The characteristics shown in Fig. 10.5.2 yield an OPP at 250 V and 48 mA, if a voltage of -7.5 V between (control) grid (g1) and cathode is chosen. This can be done e.g. by using a cathode-resistor of 142 Ω. The cathode-current (the sum of the 48-mA- plate-current and the 5-mA-screen-grid-current) will then generate a positive cathode-voltage of + 7.5 V (relative to ground). With the control-grid at ground-potential (Ug1 = 0) a control- grid-to-cathode-voltage of -7.5 V results (i.e. the control grid is negative vs. the cathode). Fig. 10.5.2: Output characteristics of the EL84, power-stage circuit (single-ended class-A operation). AP = OPP As a drive signal appears (Ug1 ≠ 0), plate-voltage and –current change. As a first approach, it will be sufficient to consider the transformer in the plate-circuit as a large inductance connected in parallel with an ohmic resistor (Chapter 10.6). In this model we have only pure DC flowing through the inductance, and only pure AC flowing through the resistor. With a drive-signal present, the Ua/Ia-point will move along the load-line given in Fig. -
Liste Des Tubes À Vide Il S'agit D'une Liste De Tubes À
Liste des tubes à vide Il s'agit d'une liste de tubes à vide ou vannes thermo-ioniques et basse pression tubes remplis de gaz ou tubes à décharge . Avant l'avènement des semi-conducteurs périphériques, des centaines de types de tubes ont été utilisés dans l'électronique grand public et industriels; aujourd'hui seuls quelques types sont encore utilisés dans des applications spécialisées. Table des matières 1 chauffage ou notes filament 2 embases de tube 3 systèmes de numérotation 3.1 systèmes nord-américain 3.1.1 système RMA (1942) 3.1.2 système RETMA (tubes recevant, 1953) 3.1.3 Chiffre systèmes uniquement 3.2 systèmes d'Europe occidentale 3.2.1 système Marconi-Osram 3.2.2 système Mullard-Philips 3.2.2.1 tubes standard 3.2.2.2 tubes de qualité spéciaux 3.2.2.3 tubes professionnels 3.2.2.4 tubes Transmission 3.2.2.5 Phototubes et des photomultiplicateurs 3.2.2.6 stabilisateurs 3.2.3 systèmes Mazda / Ediswan 3.2.3.1 ancien système 3.2.3.2 tubes de signaux 3.2.3.3 Puissance redresseurs 3.2.4 STC / Brimar système de réception des tubes 3.2.5 Tesla système de tubes de réception 3.3 système de normalisation industrielle japonaise 3.4 systèmes russes 3.4.1 tubes standard 3.4.2 tubes électriques à très haute 3,5 tubes désignation Très-haute puissance (Eitel McCullough et ses dérivés) 3.6 ETL désignation des tubes de calcul 3.7 systèmes de dénomination militaires 3.7.1 Colombie-système nommage CV 3.7.2 US systèmes de dénomination 3.8 Autres systèmes chiffre uniquement 3.9 Autre lettre suivie de chiffres 4 Liste des tubes américains, avec leurs -
1999-2017 INDEX This Index Covers Tube Collector Through August 2017, the TCA "Data Cache" DVD- ROM Set, and the TCA Special Publications: No
1999-2017 INDEX This index covers Tube Collector through August 2017, the TCA "Data Cache" DVD- ROM set, and the TCA Special Publications: No. 1 Manhattan College Vacuum Tube Museum - List of Displays .........................1999 No. 2 Triodes in Radar: The Early VHF Era ...............................................................2000 No. 3 Auction Results ....................................................................................................2001 No. 4 A Tribute to George Clark, with audio CD ........................................................2002 No. 5 J. B. Johnson and the 224A CRT.........................................................................2003 No. 6 McCandless and the Audion, with audio CD......................................................2003 No. 7 AWA Tube Collector Group Fact Sheet, Vols. 1-6 ...........................................2004 No. 8 Vacuum Tubes in Telephone Work.....................................................................2004 No. 9 Origins of the Vacuum Tube, with audio CD.....................................................2005 No. 10 Early Tube Development at GE...........................................................................2005 No. 11 Thermionic Miscellany.........................................................................................2006 No. 12 RCA Master Tube Sales Plan, 1950....................................................................2006 No. 13 GE Tungar Bulb Data Manual................................................................. -
Philips DEALING with TECHNICAL PROBLEMS
VOL. 5 N~. 3 . Philips DEALING WITH TECHNICAL PROBLEMS. RELATING TO THE PRODUCTS, PROCESSES AND. INVESTIGATIONS OF N.V. PHILIPS' GLOEILAMPENFABRIEKEN EDITED BY THE RESEARCH LABORATORY OF N.V. PHILIPS' GLOEILAMPENFABRIEKEN, EINDHOVEN, HOLLAND TESTING A~PLIFIER OUTPUT VALVES BY MEANS OF THE 'CAT~ODE RAY TUBE hy A. J. HEINS van der VEN. 621.317.755: 621.396.645 I n testing amplifier output valves, the most important data are contained in the In' v.. diagram if one knows over which part of the diagram the values of voltage and current prevailing during operatien range, i;e. if the position of the load line is known. The la- Vn 'diagrams as well as the load lines can very easily b~ obtained with the help of a 'cathode ray tube. The necessary apparatus is described in this article. A number of auxiliary ar- rangernents are also studied, by which the axes and the necessary calibration lines in the diagram can be traced on the fluorescent screen, and which make it possible to. cause the diagrams of two .output valves which are to be compared to appear simultancously on the screen. In order to obtain the load line in the correct place in the diagram, use must he made of dir'ect current push-pull amplifiers for the deflection voltages of the cathode ray tube. The position of the load line upon inductive loading is discussed and explained by a number of examples. In conclusion one,npplication of the instaflation in the develop- ment of output pentodes is dealt with. If one wishes to characterize briefly the perfor- quantrties are to some degree dependent _on the mance of an output valve of !tn amplifier or radio loading impedance which is included in the anode set, it is enough to give the sensitivity, the distor- circuit, it is first necessary to find out how the loa'd- tion as a function of the power output, and in some ing of the ~alve is e~pl'esse~ in the Ia- V~ curve.' , cases the maximum power which can he delivered mA without grid current flowing. -
INDUSTRIAL STRENGTH by MICHAEL RIORDAN
THE INDUSTRIAL STRENGTH by MICHAEL RIORDAN ORE THAN A DECADE before J. J. Thomson discovered the elec- tron, Thomas Edison stumbled across a curious effect, patented Mit, and quickly forgot about it. Testing various carbon filaments for electric light bulbs in 1883, he noticed a tiny current trickling in a single di- rection across a partially evacuated tube into which he had inserted a metal plate. Two decades later, British entrepreneur John Ambrose Fleming applied this effect to invent the “oscillation valve,” or vacuum diode—a two-termi- nal device that converts alternating current into direct. In the early 1900s such rectifiers served as critical elements in radio receivers, converting radio waves into the direct current signals needed to drive earphones. In 1906 the American inventor Lee de Forest happened to insert another elec- trode into one of these valves. To his delight, he discovered he could influ- ence the current flowing through this contraption by changing the voltage on this third electrode. The first vacuum-tube amplifier, it served initially as an improved rectifier. De Forest promptly dubbed his triode the audion and ap- plied for a patent. Much of the rest of his life would be spent in forming a se- ries of shaky companies to exploit this invention—and in an endless series of legal disputes over the rights to its use. These pioneers of electronics understood only vaguely—if at all—that individual subatomic particles were streaming through their devices. For them, electricity was still the fluid (or fluids) that the classical electrodynamicists of the nineteenth century thought to be related to stresses and disturbances in the luminiferous æther. -
A THESIS Presented to Georgia School of Technology in Partial
OPTIMUM OPERATING CONDITIONS OF A MULTI-GRID FREQUENCY CONVERTER A THESIS Presented to the Faculty of the Division of Graduate Studies Georgia School of Technology In Partial Fulfillment of the Requirements for the Degree Master of Science in Electrical Engineering William Thomas Clary, Jr. March 1948 C? . F^ 0 5fJ ii OPTIIVIUM OPERATING CONDITIONS OF A MULTI-GRID FREQUENCY CONVERTER Approved: ^2 ^L it Date Approved by Chairman Sxj- ±j /f^o iii ACKNOY^LEDGLIENTS I wish to express my sincerest thanks to Dr. W, A. Eds on for his invaluable aid and guidance in the problem herein undertaken. I also wish to thank Professor M. A. Honnell for his great assistance in carrying out the experimental study. iv PREPACK: MEANING OF SYMBOLS USED I .....Bessel*s Function of 1st kind, order m, and imaginary argument* G-m Signal electrode to plate transconductance. G_ Conversion transconductance. c E„ ...•Bias of first electrode from cathode. cl E ....Bias of third electrode from cathode. eg.....Total signal electrode voltage. e Total oscillator electrode voltage. W Angular frequency of the oscillator electrode voltage. ..g Angular frequency of signal electrode voltage. a __.•••Angular intermediate frequency. lb i .....Alternating component of plate current. iw ...Alternating component at w__, of plate current. R.•»•*.Amplitude of alternating component of signal voltage. s EQ.....Amplitude of alternating component of oscillator voltage• RT.....Plate load resistance. Li k......Boltzmann,s Constant, Tc Cathode temperature in degrees Kelvin. YQ..«..Input admittance in mho. Af•••.Frequency band width in cycles per second. a n» ^n, C ••••Empirical coefficients of plate family. -
Pentodes Connected As Triodes
Pentodes connected as Triodes by Tom Schlangen Pentodes connected as Triodes About the author Tom Schlangen Born 1962 in Cologne / Germany Studied mechanical engineering at RWTH Aachen / Germany Employments as „safety engineering“ specialist and CIO / IT-head in middle-sized companies, now owning and running an IT- consultant business aimed at middle-sized companies Hobby: Electron valve technology in audio Private homepage: www.tubes.mynetcologne.de Private email address: [email protected] Tom Schlangen – ETF 06 2 Pentodes connected as Triodes Reasons for connecting and using pentodes as triodes Why using pentodes as triodes at all? many pentodes, especially small signal radio/TV ones, are still available from huge stock cheap as dirt, because nobody cares about them (especially “TV”-valves), some of them, connected as triodes, can rival even the best real triodes for linearity, some of them, connected as triodes, show interesting characteristics regarding µ, gm and anode resistance, that have no expression among readily available “real” triodes, because it is fun to try and find out. Tom Schlangen – ETF 06 3 Pentodes connected as Triodes How to make a triode out of a tetrode or pentode again? Or, what to do with the “superfluous” grids? All additional grids serve a certain purpose and function – they were added to a basic triode system to improve the system behaviour in certain ways, for example efficiency. We must “disable” the functions of those additional grids in a defined and controlled manner to regain triode characteristics. Just letting them “dangle in vacuum unconnected” will not work – they would charge up uncontrolled in the electron stream, leading to unpredictable behaviour.