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N.3 Solar Cells and Hands

11976The first watch with solar cells and hands, the 'Citizen Quartz Crystron Solar' caliber 8620A reaches the market of Japan in August. It was a normal quartz watch with four double silicium solar cells and a stepping motor. In 1974, some periodicals had already published photographs of a solar watch with hands, these are only prototypes.
21977The first solar watch of Seiko cal. 4826. Only sold in Japan with a silver oxide rechargeable battery.
31977Mondaine markets the 'Analog-Solar'.
41978Sicura produces a model with solar cells on the right side and with date.
51983In September, Casio releases its first solar cell watches the SA 60, SA 61, SA 600, W 27 and WS 80 to WS 83, all with the QW 189 module. At the same time its calculator watches with solar cells are released: the CL 30 and the CL 301 with the QW 243 module.
61984Seiko presents the Pulsar 'Quartz Solar', caliber V102A and V103; the first solar watch which functions without any problems because the battery is replaced by a supercapacitor or large scale-capacitor. Ten minutes of sunlight suffice to charge the watch for ten days. When the capacitor is discharged and the voltage goes down to 1.2 Volt, the watch gives a warning by two seconds step motion instead of one step a second. In 1987, Seiko marketed the 8S23 with a residual power indicator, which contained a capacitor instead of a battery.
71986In June, Casio launches its first watch with a supercapacitor instead of a rechargeable battery, the FB-50 and FB-51 with module QW-520. The watch, when fully loaded, can now run for seven days.


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Copyright by Pieter Doensen

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