Perpetually self-winding mechanical clock

Perpetually self-winding mechanical clock


“Atmos” is a type of mechanical clock, manufactured in several models since 1935 by Jaeger-LeCoultre in Switzerland. The Atmos needs no batteries, no electric power, and never needs to be wound. All it requires to run indefinitely is an ambient temperature change of at least 1 degree Celsius in the range between 15 and 30 C each day. The clock stores mechanical energy from the thermal expansion and contraction of an hermetically sealed capsule containing a mixture of gaseous and liquid compounds formulated to provide maximum volumetric changes with temperature. The mechanism is illustrated here. Atmos clocks are laboriously handmade and very expensive, and are commonly gifted by the Swiss government upon visiting heads of state.

8 thoughts on “Perpetually self-winding mechanical clock

  1. jimofoz says:

    And you make it how using an Altoids can?

  2. ehrichweiss says:

    Yeah, a friend of mine is a clockmaker and he showed me one of these when one came into the shop one day.

    However, what he told me was that they worked off of the barometric pressure changing, not just temp changes. I’m sure he could be wrong but it does make more sense to have something work from the barometer than the temperature since it could easily be in a temperature controlled environment but the odds of being used in a pressure controlled environment are far less.

    1. Sean says:

      It runs from both temperature and barometric.

      A sealed aneroid will mostly be affected by atmospheric pressure. The bellows in the Atmos clock have ethyl chloride added which undergoes phase change due to temperature, it also also reacts to barometric pressure.

  3. icehouseindustries says:

    If you make this many times smaller and make many of these, isn’t this the solution to a very large energy problem?

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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