Victorinox LCD SAKs Revisited

[Max Stone]

With the demise of the LCD-equipped SAKs (Traveller, Traveller Lite, Expedition Lite and XAVT), I thought a little more info on the module in these models would be of interest.

These SAKs have a small electronic module embedded within the translucent red scale on the Victorinox shield side of the SAK. This ‘digital’ scale is slightly thicker than a normal scale, to accommodate the electronics, battery and LCD module.

With no space for typical scale tools, the toothpick, pen and short tweezers all fit into slots on the back scale. This is the same scale layout found on other translucent Plus scale models, but with an opening for the short tweezers slot. The scales have a unique matt-textured finish, presumably to partially hide the electronic circuit.

The digital scale uses a single button, cleverly shaped as a classic Victorinox shield, to select functions and make adjustments. While a single button makes it easy to cycle through the seven functions (time, altitude, barometric trend, alarm, timer, stopwatch, temperature), it’s not at all intuitive for other adjustments.

To keep the digital scale as thin as possible, there are three small cut-outs in the aluminium liner the digital scale is attached to. This accommodates a couple of larger surface-mounted components and the alarm piezo speaker, which is too soft and short duration for wake-up duty.

It’s possible to see that there is a protective conformal coating on the PCB, to protect against dust and moisture. However, the digital scale has no weatherproofing and these LCD SAKs will not survive exposure to water. As the scale cannot be user-removed, rinsing or deep cleaning are not options.

The module has two sensors, one for pressure and one for temperature. In addition to displaying temperature, the temperature sensor is used in conjunction with the pressure sensor to estimate altitude, while the pressure sensor is also used to show the barometric trend over a rolling four-hour period. The module cannot be configured for a fixed altitude (to measure pressure change over time at a fixed location), so it continuously estimates altitude based on pressure and temperature, using a standards-based model, and the altitude drifts at a fixed location as pressure changes. A known altitude can be entered manually and corrected for a standard, cold or hot climate.

The LCD module, custom-built for Victorinox, includes an unused symbol likely intended to indicate the user is at a fixed altitude, so the original design brief probably included this option. It’s also this custom-build LCD that probably contributed to the discontinuation of these LCD SAKs. It’s easy enough to get a unique PCB designed and built, but the LCD is only used by Victorinox, and I expect that the minimum order quantity for another re-order made no commercial sense, and Victorinox quietly discontinued these less-popular models, keeping spare inventory for warranty repairs.

These LCD SAKs are examples of a time when Victorinox was still developing the 91mm range. Victorinox has a different focus today, and you could argue that these LCD SAKs were never more than a curiosity. All the more reason for them to have a special place in anyone’s collection. 

[Rizio Il Ghiro]

Max, long time no see! Thanks for this detailed info!

[Max Stone]

  Thank you.

[Rizio Il Ghiro]

I have a traveller lite bought at a large discount a while ago,  and I’m sorry to say I’ve not really used it - must get it out and give it a whirl next month when I’m not on a challenge.....

[Max Stone]

Probably the pick of the LCD bunch. Basically an Explorer with LED instead of the magnifier 

[SirVicaLot]

Good to see you around, Max 

Nice write-up! I don't think i will ever own a SAK with display. Just too expensive for what it is 

[Myron]

Hey Max,

Great to see you and thanks for these insights!  I have a Traveller that I bought on sale a few months ago.  I like messing around with it, keeping an eye on the temperature, etc.  My kiddo and I used it on a weeklong road trip recently to time our total drive time.  I thought it was interesting that the clock turns over at 10 hours. 

Myron

PS, Edit to add that I did not know that Vx had discontinued these knives. 

[Max Stone]

Thanks Sir Vic, Myron

Good point about the stop watch. I guess with a display layout of H:MM:SS it will roll over at 9:59:59. This also prevents the module from showing a clock with seconds, as this needs HH:MM:SS to support a 24-hour clock. What they could have done, is use H:MM:SS when the module is set to display AM/PM, and HH:MM for 24-hour mode (as it does now). Not having a clock display with seconds is a minor negative in my books, but there again, neither does my iPhone.