TISSOT T-TOUCH MULTIFUNCTION SMART WATCH 1999
I almost do not own any modern watches but the Tissot T-Touch caught my attention by accident...and once I started wearing it... it practically became my daily beater. In general I wouldn't bother to write a review on this watch but after finding it very practical and interesting I could hardly find any indepth reviews on this watch....so here you go! It took me a while to dig for some basics in a few dozen online sources but finally I managed to find some technical insights. The 1st generation T-Touch was launched in 1999 and contained an ETA signed calibre E40.301. Initial ideas/patents were already filed as early as 1995 by the Swiss R&D laboratory Asulab owned by Swatch Group however the technical content comprises of a dozen different patents.
The first generation was available somewhere until 2004/2005 when Tissot applied a small upgrade. The case and bezel ring became just slightly wider (41.1mm vs 40mm) and the round buttons were changed to a rectangular shape. Also the new E40.305 calibre was slightly modified although the user-functionality remained exactly the same. The movement's circuit board and gear-train was redesigned while the top plastic carrier holding the dial was raised by 1mm including the zebra connectors on the front. The upgraded movement also lost the two case-mounting screws&clamps and was installed in the case with a screw-down ring providing far better water tightness. Additionally the lug shape on the case was changed so that the older bracelets are no longer compatible with later models (and you have to buy new ones).
In the next few pictures you can see the 301 and 305 circuit boards compared next to each other. The 301 can be easily identified by a steel base plate for the gear-train consisting of brass gears mounted in ruby bearings/bushings. This gear assembly can be easily disassembled for repairs although they hardly ever break down on the mechanical side. In opposition to this the later 305 calibre contains teflon-type gears fitted into plastic plates heat-sealed together. These also rarely break but when needed you will need to remove four plastic rivets as pictured below. The electro-magnetic coils are separate from the gear-train assembly which when removed reveals two double sets of coils soldered to a pertinax substrate. The coils can be removed from the circuit board by unscrewing eight screws on the back.
The circuit board is removed from the brown plastic carrier by means of three screws (2 on the edge and 1 in the middle). On the bottom side of the board there is not much to experience but you might take notice of two springs for the piezo-electric beeper and the battery clamps which are riveted to the board and sometimes might need to be repaired when broken. The largest component is the pressure sensor which is sealed and glued tightly to the board. It contains a wire-bonded thin silicone membrane made of Pyrex glass that reacts to air pressure changes and provides input to the microchip. The early 301 calibre had this sensor additionally covered with a plastic cage as shown above but later they left it totally exposed and very often vulnerable to damage by curious owners. The thicker silicone was also changed to a potting gel substance which easily atracts dirt and sand particles.
You might still wonder how the T-Touch works? As you activate Touch mode with the center button the micro-chip allows you to touch the heat-resistant electrodes on the glass. The impulse is sent to the circuitry via the zebra-strips that connect the glass with 7 pads on the board. Each of them represent one function. You can touch the zebras or pads directly when the movement is removed from the case. The T-Touch is a cool and useful watch. I can recommend it but would expect better quality for this money. The cases are made in Hong Kong and some have their flaws but the biggest problem are the buttons that tend to get lost. You'd better find a donor watch for parts as Tissot will simply tell you that they don't service old versions and suggest that you buy a new watch :) Amusing don't you think?
Keywords: tissot t-touch, tissot touch
Market value: 150$-600$-10.000$ (generation, condition, box, steel, titanium, gold)