Independents

David Walter
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Double Pendulum Resonance Clock

Hi Don,

Daniels Describes Breguet 3671 in The Art of Breguet, as a "Double Clock", initially I used the name of Double Pendulum Resonance Clock as I believe this describes it better, however this is also a mouthful of words in a name so I adopted the name of Double Pendulum clock.

Don you are exactly right, there are many clocks with two pendulums that are not resonance clocks, this again is why I called it a Double Pendulum Clock. If the clock is not operating in or with resonance, it is not a double pendulum resonance clock, it is simply a two pendulum clock.
This Breguet/Janvier type of clock operates because of resonance, without resonance it will not run at all. Removing both movements and one pendulum, start the remaining pendulum swinging and it will come to a stop within 30 seconds. With both pendulums suspended (without the movements) and start them swinging in anti-phase at their normal running amplitude they will continue to swing  for 21 hours, this is unheard of even for good regulators which may run for 6-8 hours.
 The suspension I have designed and constructed takes full advantage of resonance and has been described as a, "close to perfect closed feedback loop" in which the energy dissipation through support compliance is very small.

I too have been puzzled by the very few resonance clocks ever made, it may be because of the level of difficulty or even the cost. In making my clock I realised that it is not just one clock it is more like six clocks in one.
I think this will prove to be an extremely accurate time keeper, far better than I had anticipated, the owner of the wall mounted Double Pendulum Resonance clock will be keeping accurate records, He charts the timekeeping against the US time standard, this past week the variation including a temp. change of 8 degree C has been 0.

I hope to have a suitable video of the pendulums in motion very soon, I already have one but it is 27.5mb      

David