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Beta 21

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Beta 21 is the initial quartz watch movement produced by the Centre Electronique Horloger, a consortium of Swiss watchmakers, in 1970.

Contents

Background

Electric watches became a reality in the 1950s, with LIP and Hamilton producing commercial products by the end of the decade. Bulova's tuning fork Accutron movement appeared in 1960 and quickly gained commercial success, forcing the Swiss to investigate these developments further. Soon, Ebauches SA had their own electric watch movement, but the group felt that they would need to move quickly to develop patents in this area.

Leading Swiss watch companies pooled their resources in 1962 to create the CEH, though the organization was initially reluctant to develop quartz wrist watch technology. The initial work at CEH to develop an electronic wristwatch focused on two concepts similar in approach to the Accutron. The "Alpha" calibre used a figure 8 shaped resonator and was developed by Heinz Waldburger. The "Beta" calibre used a tuning fork coupled to a series of frequency dividers that drove a stepper motor and was championed by Max Forrer. Neither project would reach production, though elements of both were eventually incorporated into the Beta quartz movement.

Instead, it was an "underground" internal project initiated by CEH employees Armin Frei and Rolf Lochinger that would turn the organization in this direction. On November 26, 1965, CEH director Roger Wellinger declared that a "montre-bracelet à quartz" would be a goal for the group, but Max Forrer, head of the circuits department, was not interested in quartz.

Beta 1

On May 7, 1965, Armin Frei proposed to use a quartz oscillator coupled to a frequency divider similar to Forrer's Beta project. Rolf Lochinger suggested that an integrated circuit could be used as the divider, reducing power consumption. This was the basic template for the quartz Beta movement series.

The first product of this collaboration appeared in 1967 and was called the Beta 1. A prototype, known as CEH 1020, was constructed by Jean Hermann and François Niklès in July 1967, probably the first functional quartz wristwatch. It was entered in the International Chronometric Competition in Neuchâtel. Although the Beta 1 is often called the first quartz wrist watch movement, it was not intended for series production.

The Beta 1 used a bar-shaped 24 mm quartz crystal that resonated at 8192 Hz. The resulting signal was routed through a 14 stage frequency reduction chain in an integrated circuit, producing a final oscillation rate of 0.5 Hz, or one complete oscillation every two seconds. Each half-oscillation triggered a 60-position stepper motor, causing the seconds hand to advance one second in a distinctive dead beat ticking motion which has become synonymous with quartz watches today. The stepper motor used an anchor, similar to a Swiss lever escapement, but operated in reverse, with a bobbin coil moving the anchor, which pushed the anchor wheel. This complex electrical process used a great deal of power, especially the MOS integrated circuit, resulting in battery life of less than one year.

The completed prototype was enclosed in a square case and delivered to the Neuchâtel Observatory for chronometer timing. On August 13, 1967, the Observatory announced that it had reached a chronometer classification of 0.189, which was far better than any other watch tested, including the dominant Bulova Accutron. In total, ten Beta 1 watches would be sent to Neuchâtel for testing in 1967, and these beat the Seiko quartz watches sent that year thanks to the CEH thermocompensation and adjustment mechanisms.

Beta 2

Due to the power drain on the Beta 1 movement, and internal resistance to the stepper motor approach, an alternative project known as Beta 2 was initiated. It used a simplified 5-stage frequency reduction process which drove a vibration motor, similar to a tuning fork movement. This resulted in a smoother sweep similar to electronic watch movements like the Accutron and Megasonic. The reduced component could also improved battery efficiency to greater than one year. The first Beta 2 prototype was completed in August, 1967, less than a month later than the Beta 1. These were developed by Max Forrer's department, which had seen their tuning fork work cancelled at the end of 1965.

The CEH officially announced the development of a practical quartz wristwatch on December 19, 1967, becoming the first to produce and announce such a watch.

Beta 21

On February 15, 1968, CEH management decided to jointly produce a single watch movement based on these designs. The Beta 21 movement was unveiled on April 10, 1970, nine months after Longines introduced their Ultra-Quartz and four months after Seiko introduced their Astron quartz watch for sale.

The Beta 21 is an electronic movement featuring a quartz crystal oscillating at 8192 Hz. This was reduced to 256 Hz and drove a vibration motor like the Beta 2 and similar to the popular Bulova Accutron and Mosaba from Ebauches SA. For this reason, unlike more modern quartz watch movements, the seconds hand sweeps rather than ticking once per second. In contrast, the Seiko quartz movement used a stepper motor like the Beta 1, ticking once per second. The Beta 21 movement used two integrated circuit components: the quartz maintenance "command circuit", which powered the quartz rod resonator and the frequency divider "counting circuit". These were consisted of 110 electronic components on an IC less than 2 mm in size.

Just 6,000 Beta 21 movements were produced before the Swiss industry discarded the joint production concept. But individual watch companies also produced their own Beta 21-based movements:

The following companies produced Beta 21-based movements but no complete watches are known:

Beta 22

The CEH refined the Beta 21 design as the Beta 22 in the 1970's. This included an improved quartz circuit and was produced in both date and non-date models.

Known movements:

  • Rolex Oysterquartz calibre 5100 (650 made)

Beta Project Members

Further Developments

Like the Japanese and Americans, the Swiss moved on to stepper motor designs with semiconductor-based counters rather than an electronic frequency reduction chain. Omega, the strongest Beta family producer, developed their own Megaquartz movements, as did Rolex with their later Oysterquartz movements. The modern quartz watch movement, exemplified by the Swatch, has much more in common with these non-Swiss designs than the Beta 21.

External Links