First-Hand:The First Quartz Wrist Watch: Difference between revisions
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== 2. Centre Eléctronique Horloger (CEH), Neuchâtel<br> 2.1 Foundation<br> 2.2 Goal and Strategy<br><br> 3. Change of Strategy: Montre-bracelet à Quartz <br> 3.1 Status<br> 3,2 Initiative<br> 3.3 Change of Strategy<br><br> 4. The First Quartz Wrist Watch: Beta 1<br> 4.1 World First<br> '''<u><br></u>''' 5. Components of Beta 1<br> 5.1 Beta 1<br> 5.2 Quartz Resonator<br> 5.3 Driver Circuit <br> 5.4 Frequency Adjustment<br> 5.5 Temperature Compensation<br> 5.6 Frequency Divider<br> 5.7 Stepping Motor <br><br> 6. Beta 2<br> 6.1 Autonomy<br> 6.2 Wrong Strategy<br><br> 7. Beta 21<br> 7.1 Industrial Version<br> 7.2 Phase-out Model<br><br> 8. Chronology of the First Quartz Wrist Watch<br><br> 9. Rectification<br><br> 10. Bibliography == | == 2. Centre Eléctronique Horloger (CEH), Neuchâtel<br> 2.1 Foundation<br> 2.2 Goal and Strategy<br><br> 3. Change of Strategy: Montre-bracelet à Quartz <br> 3.1 Status<br> 3,2 Initiative<br> 3.3 Change of Strategy<br><br> 4. The First Quartz Wrist Watch: Beta 1<br> 4.1 World First<br> '''<u><br></u>''' 5. Components of Beta 1<br> 5.1 Beta 1<br> 5.2 Quartz Resonator<br> 5.3 Driver Circuit <br> 5.4 Frequency Adjustment<br> 5.5 Temperature Compensation<br> 5.6 Frequency Divider<br> 5.7 Stepping Motor <br><br> 6. Beta 2<br> 6.1 Autonomy<br> 6.2 Wrong Strategy<br><br> 7. Beta 21<br> 7.1 Industrial Version<br> 7.2 Phase-out Model<br><br> 8. Chronology of the First Quartz Wrist Watch<br><br> 9. Rectification<br><br> 10. Bibliography == | ||
== In July 1967, somewhat more than 40 years ago, the world's first quartz wrist watch created by a group of researchers at the Swiss Centre Electronique Horloger in Neuchâtel, Switzerland had been assembled and successfully tested for proper operation. The watch baptized Beta 1 with the identification number CEH-1020 was fully meeting the regulatory requirements concerning men's wrist watches as postulated by the established Observatory of Neuchâtel and its famous yearly "Concours des Montres". In view of the fact that the history of the invention of the quartz wrist watch has been extensively neglected and/or mistreated in the past causing misunderstandings and confusion I have investigated on "Who contributed what, at what time and what was the relevance of this contribution" restricted to the event of the creation of the world's first quartz wrist watch. <br><br><br> | == <u>1. Introduction</u> == | ||
== In July 1967, somewhat more than 40 years ago, the world's first quartz wrist watch created by a group of researchers at the Swiss Centre Electronique Horloger in Neuchâtel, Switzerland had been assembled and successfully tested for proper operation. The watch baptized Beta 1 with the identification number CEH-1020 was fully meeting the regulatory requirements concerning men's wrist watches as postulated by the established Observatory of Neuchâtel and its famous yearly "Concours des Montres". In view of the fact that the history of the invention of the quartz wrist watch has been extensively neglected and/or mistreated in the past causing misunderstandings and confusion I have investigated on "Who contributed what, at what time and what was the relevance of this contribution" restricted to the event of the creation of the world's first quartz wrist watch. <br><br><br><u>2. Centre Electronique Horloger (CEH), Neuchâtel</u><br><br><u>2.1 Foundation:</u> == | |||
== The foundation of the Centre Electronique Horloger (CEH) in 1962 was a consequence of the growing threat due to the appearance of certain kinds of wrist watches in the late 50'ies which were powered by small batteries rather then by the usual springs. Such watches had been announced by Lip (France), Hamilton (USA) and Ebauches SA (Switzerland). The introduction of Max Hetzel's Accutron, the famous tuning fork watch (picture) in 1960, accelerated this process remarkably. [[Image:Image002.jpg|thumb|right]]Hetzel was a Swiss engineer, who started his investigations with Bulova in Bienne, Switzerland and later on was transferred to U.S. to direct the production of the Accutron watch. The fear to lose leading positions on the international market assembled the Swiss watchmakers under the leadership of Ebauches SA and the Swiss Horological Federation (FH) to join in a common joint stock company called CEH. The goal was simply to invent anything which was superior in at least one count of what was available on the market. This to improve the Swiss position in possible licence negociations, a rather poor vision indeed. Luckily, they found Roger Wellinger, a U.S. bound Swiss engineer, teacher and researcher, for the challenging job to create a new research laboratory in a field which was not common at all in Switzerland. Wellinger had courage, enthusiasm and farsightedness. <br><br><u>2.2 Goal and Strategy:</u> == | |||
== The goal set up by the Swiss watch industry was to develop electronic wrist watches with at least one advantage compared to existing products (e.g. Accutron). A fairly modest goal indeed, reflecting business and legal aspects predominantly. - The strategy to reach that goal had been set up by Roger Wellinger and consisted mainly of three elements: i) recruiting and hiring Swiss scientists, who had spent a certain time in the U.S. and were willing to come back with the intention of importing technical and scientific know-how from the U.S. to Switzerland, especially in the area of semiconductors and circuits and ii) investigating all kinds of possible subsystems and later on developing new kinds of solutions similar to the morphology developed by Prof. Fritz Zwicky, Caltec. Especially in the area of sonorous resonators, frequency dividers and displays there had been a great number of various investigations resulting in a fairly complete catalogue of possibilities and iii) building up semiconductor expertise in Switzerland. – However, none of the projects until 1965 incorporated a quartz wrist watch.<sup>1)</sup> There was neither a strategy nor a project addressing a high frequency, say 10 kHz quartz wrist watch, simply because such an enterprise was considered impossible by experts and industry leaders due to the high frequencies involved and for other reasons.<sup>2)</sup> Even worse, in 1966, when the quartz wrist watch project was already established, the president of the governing board informed the two initiators of the quartz wrist watch project that the Swiss watch industry was not interested in this new kind of a quartz wrist watch!<br><br>Since the very beginning Roger Wellinger recognized the importance of an own semiconductor laboratory. That was the only way to become independent from foreign suppliers and at the same time allowed to investigate into dedicated research. Kurt Hübner and his group started quickly and very successfully developing integrated circuits (IC) capability and competence in bipolar transistor technology and double diffused, high impedance resistors. With this it was already possible in 1965 to produce the first complex IC's. CEH was certainly in a favoured position as compared to Seiko, which equipped their first quartz wrist watch calibre 1967 with discrete transistors, resistors and capacitors, about 200 of them. – Unfortunately, since Spring 1965 the CEH and its management had been confronted for more then a full year with the CISSA project. CISSA stands for "Communauté Industrielle Suisse SA", a consortium of a number of Swiss firms together with Philips, Netherlands. The purpose of this was an unfriendly buy-out of CEH's successful semiconductor department. It was above all Roger Wellinger who fought against this fatal attempts and provided for continuous fruitful cooperation between the semiconductor department and the rest of the laboratory. <br><br><br><u>3. Change of Strategy: Montre-bracelet à Quartz</u> <br><u>3.1 Status:</u> == | |||
== The strategy and plan in the field of electronic wrist watches for the year 1965<sup>6)</sup> concentrated on three topics: i) the Swissonic calibre, basically an improved version of the Accutron with increased frequency of a tuning fork wrist watch by Max Hetzel, ii) the Alpha calibre, a wrist watch incorporating a figure 8-shaped metallic resonator with zero gravitational disturbance by Heinz Waldburger, otherwise similar to the Accutron and iii) the Beta project incorporating a metallic tuning fork like i) and ii) but newly with a small chain of frequency dividers to drive a separate motor. The Beta project at that time was the only one incorporating two electro mechanical transducers, the second transducer being an electro magnetic or a piezoelectric vibrating motor. The Beta project under the direction of Max Forrer was the most elaborate project concerning time and resources and further was the only one which never reached the status of a working calibre. - The Beta project must not be confused with the later Beta 1, Beta 2 and Beta 21 calibers, which were all high frequency quartz wrist watches.<br><br><u>3.2 Initiative:</u> == | |||
== On May 7, 1965, Armin Frei and Rolf Lochinger were reviewing the situation with the existing Beta project and its technical and qualitative limitations and came up with the proposition to investigate into wrist watches which were driven by an increased frequency quartz oscillator, rather then a metal tuning fork. The two had the idea of creating a very new type of wrist watch with an accuracy and stability way beyond existing watches and way beyond Forrer's Beta project. Based on previous experience with quartz, Frei's proposal was to use a single crystal quartz oscillator at sonor frequency, say in the range of 10 kHz, miniaturize it by orders of magnitude down to dimensions required for wrist watches. The reqirement of size and power consumtion was here predominant. Lochinger proposed to investigate into integrated electronic circuits suited to master increased divisional ratios. Here the requirements of power consumtion was predominant. This was a true alternative to the existing Beta project, see above. True, the new project was risky and definitely not to the mind of our cautious department head but would certainly have a great impact on the watch industry if successful. Frei and Lochinger started their initiative immediately and agreed mutually to investigate into a new project.<br><br><u>3.3 Change of strategy:</u> == | |||
== In November, 1965 Roger Wellinger, director CEH and responsible for the yearly strategy and plan, declared the "montre-bracelet à quartz" to become the primary strategic goal for the year 1966.<sup>7)</sup> This was a direct consequence of Armin Frei having designed, built and operated successfully a miniturized quartz oscillator prototype showing feasibility of a quartz wrist watch in the 10 kHz range in 4Q65. In 1Q66 Frei disposed already of a miniaturized quartz oscillator prototype with an 8192 Hz quartz resonator (picture), a novel fully integrated driver circuit running at less than four microamps current consumption (black epoxy covered IC with red dot) and a frequency adjustment set up (upper black epoxy covered IC without a dot), all these components survived till and including the industrial phase with minor improvements only. At that time the term "montre-bracelet à quartz" appeared the first time officially in CEH's documents, and it had to be defended against the many internal and external opponents of this new direction. Never mind the rest of the quartz wrist watch was still not worked out yet or decided upon, Wellinger requested that a general systems invention disclosures on the "Montre-bracelet électronique à quartz" had to be worked out.<sup>8)</sup> == | |||
== [[Image:Prototyp 27 mm.jpg|center|625x500px]]<br>With the change of the strategy Roger Wellinger terminated abruptly Max Forrer's low frequencies Beta project with the metallic tuning fork and electromagnetic and piezoelectric actuators. – The situation at Seiko, the Japanese competitor, had been much different. They could rely on the experience with quartz clocks and electronic time keeping which they collected since 1956 (Olympics). They were developing their own quartz technology since 1958 and gradually developed quartz resonators for clocks, pocket watches and then for men's wrist watches successively.<br><br><br>'''<u>The first Quartz Wrist Watch: Beta 1</u>'''<br><br><u>World first:</u> The first quartz wrist watch was Beta 1 and it had been built at the Centre Electronique Horloger. The first unit of a series of five was assembled and tested at the CEH in July 1967. Since Seiko does not communicate any details about their first quartz wrist watch, we can firmly conclude that Beta 1 was the world's first quartz wrist watch world wide. The new watch was packed into a standard square [[Image:Image006.jpg|thumb|right]]case (picture), this was necessary because the quartz case itself was straight with a length of 27 mm. However, the overall dimensions satisfied perfectly the requirements set by the watch industry to qualify for a men's wrist watch. The watch with the identification number CEH-1020 was tested at the Observatory in Neuchâtel as of August 13, 1967,<sup>4) </sup> and reached a classification of 0.189, which means an improvement of about one order of magnitude as compared to classical chronometers.<sup>5)</sup> The classification was also much better than the one which was reached by tuning fork watches during the same period. Beta 1 was equipped with a stepping motor activating the seconds hand step by step. The alternative and later model Beta 2 was equipped with the same quartz oscillator like Beta 1, but the second hand was actuated by a 256 Hz vibrating motor and a ratchet wheel. <br><br><br>'''<u>Components of Beta 1</u>'''<br><br><u>Beta 1:</u> Beta 1 became the code name of the first quartz wrist watch. The miniaturized quartz oscillator was developed 1965/66 by Armin Frei. The same setup was used for Beta 2, a current saving alternative quartz wrist watch and later on with minor improvements in the industrial version Beta 21. The first working prototype of Beta 1, CEH 1020 had been assembled by Jean Hermann and Fraçois Niklès in July 1967.<sup>3)</sup> The main elements of the watch and their primary contributors, including parts and as well as concepts are described below:<br><br><u>Quartzresonator:</u> While the size of commercial quartz standards of those days was as big as radio tubes, we had to strive for physical dimensions to be small enough to allow the device to be mounted inside a men's wrist watch case. [[Image:Image008.jpg|thumb|right|220px]]To keep the electronics simple, the frequency had to be 2 to the power of n (n being a na- tural number) in Hertz in order to produce pulses with a period of one second at the end of the divider chain. Re- quirements, which are very much contradictory, because if the dimensions are reduced the frequency goes up and vice versa. Further we learned from experiments that quartz resonators with the shape of a tuning fork and fabricated with the technology of those days exhibit a much inferior factor of quality Q as compared to straight quartz bars. The solution to all these requirements was an x-y cut quartz bar with a length of 24 mm and with an eigenfrequency of 2<sup>13</sup> = 8192 Hz (picture). The small dimensions of the quartz in its metal case as well as the extremely stringent requirements of mechanical precision, stability and life time required special attention with regards to most of the physical parameters: Leakage rates of the case and its feeds through had to be inferior to 5 10<sup>-12</sup> Torr ltr/s, organic and anorganic deposition on the surface had to be less than 20 Angstrom thick, metallurgy and soldering of wires onto the quartz surfaces had to be free from any unwanted inclusion, high precision soldering within a fraction of one millimeter was required to reach high quality factors of the resonator and many others. The quartz on the picture was developed and tested by Armin Frei in 1965, Oscilloquartz in Neuchâtel provided for the raw material and Richard Challandes was responsible for the assembly. X-Y cut bar quartz, similar to the one on the picture but with increased frequency, had been produced in Switzerland for watches until 1977. As of 1979 the Swiss watch industry produced their 32 kHz quartz tuning fork resonators in Grenchen, Solothurn licensing Jürgen Staudte's patent on etching quartz tuning forks (USA Patent Jürgen Staudte, 1972). <br><br><u>Driver circuit:</u> A number a different circuits for driving quartz oscillators were available at the time (Clapp oscillator, etc.), none of them fulfilled the necessary requirements for our quartz wrist watch: Say no coupling capacitances, low total resistors [[Image:Image010.jpg|thumb|right|200px]]value on the chip, tolerance to the integrated circuits fabrication process and its deviations, rigid operational stability and low power consumption. This for bipolar IC's, as well as for low battery voltages. – The newly developed, symmetric cross coupled driver circuit as shown on the picture incorporates a mini- mum of four resistors with pair wise equal values R<sub>c</sub> and R<sub>e</sub> as well as two transistors Tr<sub>1</sub> and Tr<sub>2</sub> and fullfils the above requirements extremely well. The emitter resistors serve as current sources and the collector resistors provide for the negative impedances to drive the quartz. The circuit exhibits a negative impedance of -2R<sub>c</sub> approximately measured be- tween the contacts 1 and 2. The circuit was very tolerant to various applications and conditions, and easy to fabricate. It took our specialists of the semiconductor pilot line, Raymond Guye and his colleges, less than two months to ship the first fully integrated properly working chips. The circuit was developed and tested by Armin Frei in 1965 and 1966.<br><br><u>Frequency adjustment:</u> The first step in the process of adjusting the frequency to the desired value was carefully grinding off surplus material and weight at the ends of the quartz bar until a frequency was reached which, after [[Image:Image012.jpg|thumb|right|280px]]evacuation of the case, resulted in exactly 2<sup>13</sup> Hz . A very difficult and tedious job indeed. A fourteen stage divider chain would bring this frequency down to exactly one half of one Hz required to drive the stepping motor. – What about aging and other disturbing effects afterwards and during wear? To take care of this a fine tuning mechanism was needed. A stepwise variable capacitor was hooked up in series with the quartz to change the oscillating frequency of the quartz assembly by 0.2 sec/day upward or downward (picture). At that time Fritz Leuenberger of the semiconductor department started his research on MOS transistors, an excellent chance to integrate on a single chip a series of discrete MOS capacitors, high value and small volume, exactly what we wanted. The design and layout was made in 1966 by Armin Frei, the semiconductor department delivered the MOS capacitor chip and the watch maker technician Claude Challandes designed the miniature switch.<br><br><u>Temperature compensation:</u> The irregularities in time keeping of quartz wrist watches are due to the temperature sensitivity of the various physical parameters of the quartz crystal itself and not of the electronics attached to it. The deviation [[Image:Image014.jpg|thumb|right|220px]]in time is measured in se- conds per day as a function of temperature. The resulting plot, usually displayed between 4° C and 36° C is a com- plicated function of the cutting angels relative to the axes of the quartz crystal itself. At the time it was well known, that the x-y cut quartz crystals exhibit parabolic curves according to the curve a) in the picture. We were very much aware that the manufacturers of the current me- chanical watches were keen to keep the temperature deviation as small as possible, so we engaged strongly in the disciplines of temperature compensation. First inves- tigations using temperature sensitive resistors and capa- citors were not very successful. Jean Hermann proposed in 1967, shortly before the very first quartz wrist watch was operating, a scheme using the parabolic behavior twice and a switch to connect a compensating capacitor at 12°C ac- cording to curve b). This scheme was easy to implement, produced favorable results with the observatory tests and was effectiv during daily usage. Yet it required extensiv interventions by the laboratory director on behalf of the department head in order not to drop the brilliant idea. The resulting Thermo Compensation Module (TCM) was developed by Jean Hermann and was implemented using MOS technology by Fritz Leuenberger and his group in 1967. <br><br><u>Frequency divider:</u> Since the very beginning of the quartz wrist watch project Armin Frei decided that the oscillating frequency of the quartz had to be to 2<sup>13</sup> = 8192 Hz. Consequently for Beta 1 using a stepping motor to drive the second hand, see below, a [[Image:Image016.jpg|thumb|right|180px]]total of 14 binary flip-flop stages were required to drive the motor of the watch with pulses of half a Hertz repetition frequency. The flip-flops which were finally incorporated in the Beta 1 prototypes (picture), were designed by Jean Fellrath and implemented in integrated form by Raymond Guye and his group in bipolar technology. The circuits were optimized for low power consumption of approximately one microamp per stage and for high operational stability. While integrated counter stages at microwatt level existed since before, the flip-flop shown exhibits a new type of triggering circuits, one of them on each side, and it also uses direct coupling between collectors and opposite base similar to the oscillator circuits, see above. - In bipolar technology the divider chain with 14 stages represented a big load for the battery, limiting its lifetime to less than one year, much to the concern of certain members of the governing board. The immediate solution to that would have been a reduction of the number of divider stages, say 5, reduce the frequency to 256 Hz rather than half a Hz and use a vibrating motor rather then a stepping motor. This was alternatively proposed with the Beta 2 and the Beta 21 projects 1967 and 1968 respectively. - However the real solution to the power consumption problem were ultimately the Complementary Metal Oxide Silicon circuits (CMOS), which had been invented in USA (Frank Wanlass, 1963) a couple of years before. <br><br><u>Stepping motor:</u> All that was left was to convert the pulses appearing at the end of the divider chain into step by step advancements of the second hand. Jean Hermann and François Niklès proposed in 1967 a simple solution of such a stepping [[Image:Image018.jpg|thumb|right|150px]]motor for Beta 1 as seen in the picture. The setup incorporated an anchor wheel and an anchor which were responsible for the go and stop of the second hand. Much different as in mechanical watches, where the anchor and the anchor wheel act as escapement, here the anchor drives the anchor wheel by wiggling forth and back. The anchor was activated by means of a bobbin coil, which was attached to the anchor and which was magnetized by bipolar electric pulses. The duration and the amplitude of the pulses had to be well controlled to warrant proper operation and to save battery power. The duration of the pulses were derived from the pulse pattern appearing along the divider chain using boolean logic. The concept and the basics had been worked out as early as 1966. == | == [[Image:Prototyp 27 mm.jpg|center|625x500px]]<br>With the change of the strategy Roger Wellinger terminated abruptly Max Forrer's low frequencies Beta project with the metallic tuning fork and electromagnetic and piezoelectric actuators. – The situation at Seiko, the Japanese competitor, had been much different. They could rely on the experience with quartz clocks and electronic time keeping which they collected since 1956 (Olympics). They were developing their own quartz technology since 1958 and gradually developed quartz resonators for clocks, pocket watches and then for men's wrist watches successively.<br><br><br>'''<u>The first Quartz Wrist Watch: Beta 1</u>'''<br><br><u>World first:</u> The first quartz wrist watch was Beta 1 and it had been built at the Centre Electronique Horloger. The first unit of a series of five was assembled and tested at the CEH in July 1967. Since Seiko does not communicate any details about their first quartz wrist watch, we can firmly conclude that Beta 1 was the world's first quartz wrist watch world wide. The new watch was packed into a standard square [[Image:Image006.jpg|thumb|right]]case (picture), this was necessary because the quartz case itself was straight with a length of 27 mm. However, the overall dimensions satisfied perfectly the requirements set by the watch industry to qualify for a men's wrist watch. The watch with the identification number CEH-1020 was tested at the Observatory in Neuchâtel as of August 13, 1967,<sup>4) </sup> and reached a classification of 0.189, which means an improvement of about one order of magnitude as compared to classical chronometers.<sup>5)</sup> The classification was also much better than the one which was reached by tuning fork watches during the same period. Beta 1 was equipped with a stepping motor activating the seconds hand step by step. The alternative and later model Beta 2 was equipped with the same quartz oscillator like Beta 1, but the second hand was actuated by a 256 Hz vibrating motor and a ratchet wheel. <br><br><br>'''<u>Components of Beta 1</u>'''<br><br><u>Beta 1:</u> Beta 1 became the code name of the first quartz wrist watch. The miniaturized quartz oscillator was developed 1965/66 by Armin Frei. The same setup was used for Beta 2, a current saving alternative quartz wrist watch and later on with minor improvements in the industrial version Beta 21. The first working prototype of Beta 1, CEH 1020 had been assembled by Jean Hermann and Fraçois Niklès in July 1967.<sup>3)</sup> The main elements of the watch and their primary contributors, including parts and as well as concepts are described below:<br><br><u>Quartzresonator:</u> While the size of commercial quartz standards of those days was as big as radio tubes, we had to strive for physical dimensions to be small enough to allow the device to be mounted inside a men's wrist watch case. [[Image:Image008.jpg|thumb|right|220px]]To keep the electronics simple, the frequency had to be 2 to the power of n (n being a na- tural number) in Hertz in order to produce pulses with a period of one second at the end of the divider chain. Re- quirements, which are very much contradictory, because if the dimensions are reduced the frequency goes up and vice versa. Further we learned from experiments that quartz resonators with the shape of a tuning fork and fabricated with the technology of those days exhibit a much inferior factor of quality Q as compared to straight quartz bars. The solution to all these requirements was an x-y cut quartz bar with a length of 24 mm and with an eigenfrequency of 2<sup>13</sup> = 8192 Hz (picture). The small dimensions of the quartz in its metal case as well as the extremely stringent requirements of mechanical precision, stability and life time required special attention with regards to most of the physical parameters: Leakage rates of the case and its feeds through had to be inferior to 5 10<sup>-12</sup> Torr ltr/s, organic and anorganic deposition on the surface had to be less than 20 Angstrom thick, metallurgy and soldering of wires onto the quartz surfaces had to be free from any unwanted inclusion, high precision soldering within a fraction of one millimeter was required to reach high quality factors of the resonator and many others. The quartz on the picture was developed and tested by Armin Frei in 1965, Oscilloquartz in Neuchâtel provided for the raw material and Richard Challandes was responsible for the assembly. X-Y cut bar quartz, similar to the one on the picture but with increased frequency, had been produced in Switzerland for watches until 1977. As of 1979 the Swiss watch industry produced their 32 kHz quartz tuning fork resonators in Grenchen, Solothurn licensing Jürgen Staudte's patent on etching quartz tuning forks (USA Patent Jürgen Staudte, 1972). <br><br><u>Driver circuit:</u> A number a different circuits for driving quartz oscillators were available at the time (Clapp oscillator, etc.), none of them fulfilled the necessary requirements for our quartz wrist watch: Say no coupling capacitances, low total resistors [[Image:Image010.jpg|thumb|right|200px]]value on the chip, tolerance to the integrated circuits fabrication process and its deviations, rigid operational stability and low power consumption. This for bipolar IC's, as well as for low battery voltages. – The newly developed, symmetric cross coupled driver circuit as shown on the picture incorporates a mini- mum of four resistors with pair wise equal values R<sub>c</sub> and R<sub>e</sub> as well as two transistors Tr<sub>1</sub> and Tr<sub>2</sub> and fullfils the above requirements extremely well. The emitter resistors serve as current sources and the collector resistors provide for the negative impedances to drive the quartz. The circuit exhibits a negative impedance of -2R<sub>c</sub> approximately measured be- tween the contacts 1 and 2. The circuit was very tolerant to various applications and conditions, and easy to fabricate. It took our specialists of the semiconductor pilot line, Raymond Guye and his colleges, less than two months to ship the first fully integrated properly working chips. The circuit was developed and tested by Armin Frei in 1965 and 1966.<br><br><u>Frequency adjustment:</u> The first step in the process of adjusting the frequency to the desired value was carefully grinding off surplus material and weight at the ends of the quartz bar until a frequency was reached which, after [[Image:Image012.jpg|thumb|right|280px]]evacuation of the case, resulted in exactly 2<sup>13</sup> Hz . A very difficult and tedious job indeed. A fourteen stage divider chain would bring this frequency down to exactly one half of one Hz required to drive the stepping motor. – What about aging and other disturbing effects afterwards and during wear? To take care of this a fine tuning mechanism was needed. A stepwise variable capacitor was hooked up in series with the quartz to change the oscillating frequency of the quartz assembly by 0.2 sec/day upward or downward (picture). At that time Fritz Leuenberger of the semiconductor department started his research on MOS transistors, an excellent chance to integrate on a single chip a series of discrete MOS capacitors, high value and small volume, exactly what we wanted. The design and layout was made in 1966 by Armin Frei, the semiconductor department delivered the MOS capacitor chip and the watch maker technician Claude Challandes designed the miniature switch.<br><br><u>Temperature compensation:</u> The irregularities in time keeping of quartz wrist watches are due to the temperature sensitivity of the various physical parameters of the quartz crystal itself and not of the electronics attached to it. The deviation [[Image:Image014.jpg|thumb|right|220px]]in time is measured in se- conds per day as a function of temperature. The resulting plot, usually displayed between 4° C and 36° C is a com- plicated function of the cutting angels relative to the axes of the quartz crystal itself. At the time it was well known, that the x-y cut quartz crystals exhibit parabolic curves according to the curve a) in the picture. We were very much aware that the manufacturers of the current me- chanical watches were keen to keep the temperature deviation as small as possible, so we engaged strongly in the disciplines of temperature compensation. First inves- tigations using temperature sensitive resistors and capa- citors were not very successful. Jean Hermann proposed in 1967, shortly before the very first quartz wrist watch was operating, a scheme using the parabolic behavior twice and a switch to connect a compensating capacitor at 12°C ac- cording to curve b). This scheme was easy to implement, produced favorable results with the observatory tests and was effectiv during daily usage. Yet it required extensiv interventions by the laboratory director on behalf of the department head in order not to drop the brilliant idea. The resulting Thermo Compensation Module (TCM) was developed by Jean Hermann and was implemented using MOS technology by Fritz Leuenberger and his group in 1967. <br><br><u>Frequency divider:</u> Since the very beginning of the quartz wrist watch project Armin Frei decided that the oscillating frequency of the quartz had to be to 2<sup>13</sup> = 8192 Hz. Consequently for Beta 1 using a stepping motor to drive the second hand, see below, a [[Image:Image016.jpg|thumb|right|180px]]total of 14 binary flip-flop stages were required to drive the motor of the watch with pulses of half a Hertz repetition frequency. The flip-flops which were finally incorporated in the Beta 1 prototypes (picture), were designed by Jean Fellrath and implemented in integrated form by Raymond Guye and his group in bipolar technology. The circuits were optimized for low power consumption of approximately one microamp per stage and for high operational stability. While integrated counter stages at microwatt level existed since before, the flip-flop shown exhibits a new type of triggering circuits, one of them on each side, and it also uses direct coupling between collectors and opposite base similar to the oscillator circuits, see above. - In bipolar technology the divider chain with 14 stages represented a big load for the battery, limiting its lifetime to less than one year, much to the concern of certain members of the governing board. The immediate solution to that would have been a reduction of the number of divider stages, say 5, reduce the frequency to 256 Hz rather than half a Hz and use a vibrating motor rather then a stepping motor. This was alternatively proposed with the Beta 2 and the Beta 21 projects 1967 and 1968 respectively. - However the real solution to the power consumption problem were ultimately the Complementary Metal Oxide Silicon circuits (CMOS), which had been invented in USA (Frank Wanlass, 1963) a couple of years before. <br><br><u>Stepping motor:</u> All that was left was to convert the pulses appearing at the end of the divider chain into step by step advancements of the second hand. Jean Hermann and François Niklès proposed in 1967 a simple solution of such a stepping [[Image:Image018.jpg|thumb|right|150px]]motor for Beta 1 as seen in the picture. The setup incorporated an anchor wheel and an anchor which were responsible for the go and stop of the second hand. Much different as in mechanical watches, where the anchor and the anchor wheel act as escapement, here the anchor drives the anchor wheel by wiggling forth and back. The anchor was activated by means of a bobbin coil, which was attached to the anchor and which was magnetized by bipolar electric pulses. The duration and the amplitude of the pulses had to be well controlled to warrant proper operation and to save battery power. The duration of the pulses were derived from the pulse pattern appearing along the divider chain using boolean logic. The concept and the basics had been worked out as early as 1966. == |