Pulsar Calculator Watch
Showing the considerable thickness of the Pulsar (15 mm/0.6").
Pulsar calculator watch 3822-2.
Distinctive features: The first electronic calculator watch.
Display is 6 digits, red LED, though calculations are performed to 12-digits.
4-function, %, time & date.
Power supply: 5v (4x button cells).
Size of calculator/watch case 36 x 43 x 15 mm (1.4" x 1.7" x 0.6").
Pulsar calculator watches were launched in 1975, and were available in gold and stainless steel. Similar, updated models, like this stainless steel version, were introduced in 1977.
Case made in Switzerland, electronics module made in U.S.A., by Time Computer Inc.
Due to the high power consumption of the LED display, the display is normally blank. Pressing the button marked "Pulsar" displays the time for a couple of seconds. On this later model the time can also be displayed by a
flick of the wrist.
As well as hours/minutes the watch can display day of the week and date.
Calculator mode is entered by pressing the "+" button, and the display then stays on until unused for about 20 seconds.
Like all LED calculator watches, since the display uses so much power the time is only displayed for a few seconds after pressing the "Pulsar" button, or, on this version, flicking the wrist.
In calculator mode the display is blanked after about 20 seconds, if not used.
A Pulsar calculator watch in its case.
To the left is a Pulsar pen/stylus, which has a retractable ball point pen at one end and a retractable stylus at the other for operating the tiny calculator buttons.
The rear cover removed showing the 4 button cells.
On the right towards the top is the metal can containing the crystal oscillator, and below it is the trimmer to adjust the time regulation.
By 1975 the electronics required for a calculator had shrunk so much that it could be shoe-horned into a watch casing. The first was the Pulsar calculator watch, made by Time Computer Inc., of Lancaster, Pennsylvania, U.S.A., formerly the Hamilton Watch Company. This was followed over the next couple of years by models from Hewlett Packard (HP-01), Compuchron, and Uranus - all with LED displays. Sinclair produced an LED wrist calculator, but without the time function.
LED calculator watches were marketed for only a few years before being replaced by LCD (Liquid Crystal Display) version, which have much lower power consumption and display the time continuously.
The rate of development was so fast that LED watches and calculator watches were often left unsold, and are now sometimes available to collectors as new old stock (NOS).
For more information about Pulsar LED watches and calculator watches see the article The Pulsar Calculator Watch "For the man who had everything" by Guy Ball on this site. There is much fascinating information about LED watches, including details of some very rare models, at Crazy Watches site at http://www.crazywatches.pl/led,1.
© Text & photographs copyright Nigel Tout 2000-2021 except where noted otherwise.