The neon glow lamp has found extensive circuit component use as a switch in relaxation oscillator applications. The two basic types of relaxation oscillators are the sawtooth oscillator and the astable (free running) multivibrator. This chapter will present various configurations of each type of glow lamp relaxation oscillator and will examine their operating characteristics. Design aids will be given to assist the circuit designer in utilizing the glow lamp in his circuit applications.
There are two important heavily biased relaxation circuits. One type is known as gate, one-shot, or univibrator circuits, the other general class being known as trigger or flip-flop circuits. The gate circuit operates with one or both tubes so heavily biased that the circuit is inactive until a comparatively strong synchronizing or triggering voltage is applied. This strong signal causes the circuit to change from its stable limiting Sec. 19-3 HEAVILY BIASED RELAXATION CIRCUITS 417 conducting. The current through this tube given by the relation
Another potential source of frequency instability is magnetic domain relaxation that can occur in the magnetic shielding and C field structure. When a change is made in the C field, the shields take a relatively long time to relax, or reach equilibrium. Relaxation can also occur due to changes in external magnetic fields, temperature changes, power interruptions, and shock. Relaxation changes the value of the static mag netic field established by the stable current flowing through the C field winding. Since the frequency of the resonator depends on the value of the C field, relaxation produces frequency changes in the standard. For this reason, the improved tube has a built-in degausser coil that provides a means of hastening the relaxation of the magnetic domains to equilibrium. This complete degaussing provides improved repeatability and settability.
A short time ago I finished building a monitor scope for my SSB rig and i found that I needed a 30 Hz sweep generator. It had to be a sawtooth wave, so that let out using a 60 Hz sine wave. Not needing a fancy generato I thought )ack to a simplex experiment that I performed at college using a neon bulb as a relaxation oscillator for producing a sawtooth wave.
Raised in Tucson, Arizona, John Faick earned BSEE (1972) and MSEE (1974) degrees at the University of Arizona and then joined HP's Santa Rosa Division. Initially he worked on the 8565A Microwave Spectrum Analyzer and then went on to the IF and display portions of Model 8568A. John's married. For relaxation, he enjoys photography, listening to music, and playing racquet ball.
A modification of the relaxation oscillator shown in figure 34 is shown in figure 38. This is substantially the same as that shown in figure 34, except that a current limiting tube is used in place of the current control resistor R. Also that the unit is shown with output connections to the deflection plates of the oscillograph tube. The function of the type 34 pentode incidentally, it is not imperative that this tube be exactly this pentode is to keep the flow of current charging the condensers Cl, C2 or C3, whichever is in the circuit, at a constant value during the entire charging cycle. If this is done, then the rise of the voltage is at a constant rate and the output is linear. Fig. 38. The type 34 tube replaces the resistor, R, (Fig. 34) as a current limiting device in this relaxation oscillator sweep circuit. The constant current flow tends to charge whatever condenser is in the circuit at a constant rate, making the voltage rise constant thereby supplying a linear output to...
A second type of relaxation oscillator which employs neon glow lamps is the astable or free-running multivibrator. The normal configuration employs two glow lamps with associated resistors and capacitors. The frequency or repetition rate is again determined by the operating characteristics of the lamps, the external resistance and capacitance, and the supply voltage. The upper frequency limit of the multivibrator is generally about 10 kilocycles per second. Several types of output waveforms are obtainable from the glow lamp multivibrator.
In 1919 Abraham and Block described the multivibrator, a type of relaxation oscillator having an output rich in harmonics. This device was used to multiply frequencies by harmonic methods to obtain low and medium radio frequencies from an audio-frequency standard oscillator, such as a tuning fork. A little later. Dye incorporated such a standardiz
This material possesses very nearly the ideal characteristics dielectric constant and low dissipation factor that are invariant with frequency. Measurements from dc to at least several hundred megacycles show substantially constant values of these parameters. Mica, on the other hand, exhibits marked polarizations at frequencies below the audio range. These are manifested by rising values of capacitance and dissipation factor at the low end of the audio range. The relaxation times of these polarizations
A graduate (diplom Ingenieur) of the University of Karlsruhe, Germany, Erich Courtin joined HP in 1968, working initially on the Model 8026A Ultrasound Monitor and then becoming project leader for the 15180A Ultrasound Transducer Preamplifier. In 1972 he became section leader responsible for the development of the 8021A and 8030ACardiotocographs. For relaxation, Erich plays table tennis or the violin. He and his wife have two children, 5 and 7.
Such third party traffic may be directed to other amateur operators in Germany only concerning the subject satellite operation. There is no change in the status of the general conditions relative to normal third party traffic between the Federal Republic of Germany and the United States. The Commission concurs, therefore, with the limited relaxation of third party traffic concerning OSCAR 6 and has no objections to Amaerican amateur operators engaging in such exchanges of information
The van der Pol relaxation oscillator shown in Fig. 18-22 may be converted into a gate circuit by applying a negative bias to the suppressor grid or by reducing the value of the resistor R2. As already discussed in Sec. 18-9, the principle of the circuit is essentially the same as that of the two-tube multivibrator, except that
Researchers at Notre Dame University have approached the study of material damping capacity from the beginning, rather than the end. One of the most common procedures for measuring the internal friction of material is the resonance-bar technique, wherein a sample of the material to be studied is cut to the proper dimensions for resonance at some desired frequency in some specific mode of vibration. Damping is determined either with the specimen at resonance or in free decay from resonance. Dr. N. F. Fiore and R. M. Brach of Notre Dame have successfully developed a third variation of the technique in which the damping is determined by the relaxation time (r ), characterizing the rate at which the system builds-up to steady-state resonance vibration. The method described above is unique in that it allows one to have his cake and to eat it too. As long as the pulse duration exceeds Tfti the decrement can be determined directly from the relaxation time. When the pulse ends, the sample-rod...
The sweep oscillator at the setting made to develop the proper image. As stated before, one of the properties of a relaxation oscillator, such as is used to produce the timing axis, is to keep step with a frequency which is applied to the input circuit of the oscillator. The sweep oscillator will keep step with this synchronizing pulse, be the pulse a sub-multiple or a multiple of the frequency of the sweep oscillator. This locks the image and it stands stationary upon the screen. It is necessary that you understand the operation of the synchronizing adjustment, otherwise you will find it extremely difficult to produce a stationary pattern upon the screen. The frequency adjustment of the sweep circuit, when correct, will stop the image, but the image will not stand stationary, because of slight drift in the source of the voltage being observed and in the relaxation oscillator. But when the sweep has been synchronized with the voltage under observation, the pattern will remain...
The frequency of the relaxation oscillator, described in the preceding paragraph, depends upon the size of R and C, and upon the comparative voltage at which the glow-tube strikes, and the battery voltage. Suppose we keep everything the same except the resistance R. As R is decreased, the time required to fill the condenser becomes less and less and the frequency of oscillations is increased, as shown in Fig. 22.3 An Approximately Linear Sweep-Circuit. For use with an oscilloscope, we desire a curve of the saw-toothed shape shown in Fig. 22 F, rather than that developed by the simple relaxation oscillator just described. Voltages of the type shown in Fig. 22 F, when applied to the horizontal deflecting plates of the cathode-ray tube, will produce a linear sweep 1 of the electron beam across the screen. This means that The voltages developed by the simple relaxation oscillator described e
Neal's spare time is time-shared, too, between teaching and relaxation. He teaches electronics and math at West Valley College, Foothill College, and San Jose City College, and he must be one of very few engineers who hold a California State Standard Designated Teaching Credential. For relaxation, it's sailing, gardening, chess, or the study of classical music.
Much of the presently-available patient monitoring instrumentation is used to assess heart function. The reasons for this are twofold. First, heart disease is a leading killer. Second, the electrical depolarization and repolarization potentials that accompany the rhythmic contraction and relaxation of the heart muscle are readily-available and highly meaningful signals. electrical field generated by the heart is an aggregate of the electrochemical activities of each of the muscle cells, going through the contraction-relaxation cycle. The muscle cells forming the walls of the heart's pumping chambers contract during each pumping cycle, decreasing the chamber volume and forcing blood out. In the normal heart, the electrical activity propagates along well-defined paths with propagation velocities that vary along the path. This pattern of electrical activity results in synchronization and appropriate time relationship in the contraction of the upper receiving chambers (atria) and lower...
Rolf Schmidhauser designed many of the circuits in the 5326A B Timer Counter. At HP since 1968, he is a 1965 graduate of the Swiss Federal Institute of Technology, Zurich. He holds the degree DiplomIngenieur in electrical engineering. As a result of his work on the 5326A B and previous instruments, Rolf has several patents pending. He is presently working on some special IC's for the 5326 family, and he plans to continue in IC development in the future. For relaxation, he likes to go hiking in the Sierra Nevada and in the foothills.
In the early 1950s, I read a description of a relaxation oscillator using the reverse-breakdown characteristic of a 1N34 diode. The circuit was identical to the neon-lamp oscillator except for the reverse-biased diode replacing the neon lamp. I built such an oscillator and it worked. Evidently, the 1N34 exhibited a negative-resistance region in its reverse-breakdown characteristic.
The multivibrator, or relaxation oscillator, is used for the generation of nonsinusoidal waveforms. The output is rich in harmonics, but the inherent frequency stability is poor. The multivibrator may be stabilized by the introduction of synchronizing voltages of harmonic or subharmonic frequency.
Ago Kiss began his varied professional career in his native Hungary doing research in nuclear particles and electromagnetic interactions. After five years he moved to England, where he spent another five years, first as a research physicist and then as a consultant in control systems. In 1962 he came to the United States and spent three years developing bandwidth reduction and coding techniques before joining the staff of Hewlett-Packard Laboratories in 1965. At HP, Ago has worked on character recognition and gas Chromatograph control, and since 1967 has been engineering group manager in charge of the development of Fourier Analyzers. Ago wes responsible for defining the 5450A Fourier Analyzer and developing its algorithms. Ago studied electrical engineering at the Polytechnical University of Budapest, and physics and math at the University of Sciences in Budapest. He has also done postgraduate work at the University of Pittsburgh. He holds several British and U.S. patents related to...
Youngest but most zealous members of TUARC. After his first meeting with Rick BZ1QL, In November 1992, the open-minded, smart boy quickly became hooked on the hobby, and has been very much involved in almost ail of the club activities since. What a terrific relaxation, working on the radio while forgetting about the pressure from schooling Crazy about constructing antennas. Sean is also starting to teach himself CW through the SuperMorse program, and may be heard on the tow bands from lime to time during the winter season. Acting as a Public Relations Group member, he not only does a super job as BZ1LUV, but also gets the hang of his university subjects very well. We are always learning, both about the radio and about the life, especially about getting along with various kinds of pecple. TUARC has taught me a lot of things, and I am very lucky to be in this club and know these guys.
The other day the family left me alone with the house and it was peaceful, I sat down at the rig with full intentions of enjoying a few hours of pX-chasing or rag-chewing, whichever seemed most probable. With the earphones in place, the warmed tubes of my hearing aid greeted me with the loudest racket I have ever heard. My S-meter spun over to S-9+ without a signal coming through. Needless to say* my spirits dropped to rock bottom and my relaxation was shattered. After a few choice invectives, t started
I (B) and briefly go over how (he I1 r basic relaxation oscillator works. At the beginning of the operating cycle the emitter is tiou-con dueling since no operating voltage is being applied, Applying voltage at +V1 terminal allows capacitor CT to charge through resistor RT. As the emitter voltage at point VE rises exponentially towards the level of +V1 the supply voltage, a point VP, the emitter's peak point voltage, is reached. At this instant the dynamic resistance between the emitter and base-one drops to a low value.
Mike Neering joined HP in Palo Alto in 1971, initially working on automatic network analyzers before going on to the video and display processing circuits of Model 8568A. A native of Bay City, Michigan, Mike earned a BSEE degree at Michigan State University In 1969, and an MSEE degree at Stanford in 1970 on a fellowship. He's married, has two small children, plays golf in an HP league, enjoys bowling, skiing, and tennis, and plays piano for relaxation.
The latter provision makes me wonder if the authorities ever take any notice of rules and regulations that have been previously Implemented. The liberalization of British Telecom and relaxation of their monopoly included the provision that sut scribers could, for the first time, buy extension and other telephone equipment from high-street stores.
Such a meeting has been arranged for the week of January 8-15th in Aspen, Colorado. Here, with over 100 restaurants to pick from, there will be a series of extended dinner meetings so the ham industry can discuss its problems and work out some possible solutions. Manufacturers, dealers, and just plain interested hams are invited to join the group in Aspen for some skiing, some relaxation, and a lot of serious business.
Refer to Fig, Ij you will see that transistors Q and Q2 make up a differential amplifier, which means both collectors will be at the same potential whenever the signal levels at the bases are equal. If they are not, then one collector will be higher than the other. The diodes D1 and D2 allow the base of the emitter follower Q3 to follow the higher collector This puts the signal onto the 0 k resistor connected to the emitter of the UJT, and affects the time constant of the 15 k and the ,1 mF capacitor. This varies the frequency of the UJT relaxation oscillator, which drives the speaker
For the 100-Hz-to-300-MHz frequency range, the 8091A Rate Generator module uses the same monolithic-IC oscillator circuit as the Model 8082A 250-MHz Pulse Generator. For frequencies above 300 MHz, a thin-film hybrid circuit based on the well-known emitter-coupled oscillator circuit is used (Fig. 6.). It is a relaxation oscillator with a repetition rate determined by capacitor C and the collector load resistors.
There has l een a big change in CS due to the relaxation of the FCC rules permitting what had previously been illegal (virtually all of the CB communications , the present extreme low in sunspot activity and resultant lack of 11m skip, and the large influx of truck drivers spreading their friendly greetings to i ach other , . and to the iittte four wheelers getting in their way.
The ideal saw-tooth wave output of a relaxation oscillator is that shown in figure 32. This was drawn and affords a good comparison with the photograph of the neon tube oscillator output shown in figure 31. Note that the rise in voltage in figure 32 is constant with respect to time and that the discharge time is theoretically zero, since it is a straight line from maximum to minimum. The variation of the voltage increase, being a straight line, is linear, in contrast with the exponential variation of figure 31. With figure 32 as a basis, we can compare ways and means of securing the closest approach to the ideal and note the discrepancies of various forms of sweep circuits. Incidentally, very satisfactory application of the cathode-ray tube is possible with an approach to the ideal saw-tooth sweep voltage.
Modern medicine is based upon the tenet that life processes, both normal and pathological, are essentially complex physical phenomena, which follow the physical laws elucidated by modern physical science. Electronics is important to the modern physician and medical scientist in many ways. Two are discussed here. First, many life processes are ionic in nature and produce concomitant electrical signals. These include propagation of nerve impulses along nerve fibers, and the electrical depolarization and repolarization of muscle cell membranes during muscular contraction and relaxation. Secondly, by transducing non-clectrical phenomena into electrical signals, electronic instruments are useful for detection and measurement of non-electric events which play important roles in life processes. These include pressures, flows, chemical concentrations, etc.
In almost all types of construction and fabrication a knowledge ol time consumed serves as a basis of cost analysis and is of great importance to all concerned. This is not exactly true in the case of home constructed equipment as the cost of time consumed is not important, being charged, usually, to enjoyment, education and relaxation.
Chung Tung received his BSEE degree from National Taiwan University in 1961 and his MSEE degree from the University of California at Berkeley in 1964. As a member of HP Laboratories from 1965 to 1972, he was involved in the design of the 9100 Calculator and the HP-35 and HP-45 Pocket Calculators. He subsequently joined the Advanced Products Division as manager of the HP-65 project and is now engineering section manager there. Chung has done work towards his PhD degree at Stanford University, although he isn't presently enrolled there. He is married, has a son and a daughter, and lives in Santa Clara, California. Music, reading, and table tennis are his principal modes of relaxation.
For several years, the Federation of Amateur Radio Societies of India had been making representations to the government, requesting relaxation of import controls without much success The improvement in the foreign exchange position enabled the government to make concessions to certain users-among them scientists and professionals who were allowed to
Clock pulses i or the memory are generated by a relaxation oscillator corv sislEng of Q1 and 02 and associated parts.1 The oscillator is the same one used in my keyer and was selected so that the speed controls could be ganged and would 'rack in the event thai the keyer would be packaged with the memory (it wasn't).
The Indian electronics industry had enjoyed a shettered market dominated by the favored few who had been given industrial licenses to make electronic products- One fine day, the Prime Minister made a statement in Parliament, indicating imminent relaxation of these restrictions. What followed was a wholesale liberation of the industry from its shackles. The electronics industry has not yet responded to this move with any tangible results reduced prices or better products. The Prime Minister recently warned the industry to take heed that Government wilt go to any extent to see that the benefits of liberalization reach the common man,
Start unlocking your hidden power with self hypnosis by relaxing and staying relaxed. This is just the audio you have been looking for to do just this.