Direct Drive Linear Generator Wave Machine

After reviewing the wecTYPES and the wec Patents and numerouse theses & papers it was obvious that the bobbing float Point Absorber (PA) type with a Direct Drive Linear Generator power take off (PTO) would be the best for us because it is easiest, most reliable & cheapest to build.

Linear Generator

above water


Motive Float

Point Absorber



Frame Work

Drawing of design, above, & photo of PA model, below

Investigations of linear generators led us to the above design.

Photo of one of the magnet plungers for testing in model.

It is well known that, doubling the speed of moving the magnet plunger past the wire coils will double the voltage (in general for open cuircuit voltage in generators).

The main problems with wave energy conversion are:

   1.  the long time period between     
        waves from 2 to 8 seconds
        generally (avg, 5 sec.); and,

    2. the irregular nature of successive
         wave profiles.


Hence, with respect to wave machine direct drive linear generators:

    1. the stroke cycle  is 2.5 sec (avg.)
        which in a rotating generaor
        would be 60/2.5 = 24 RPM (7.5
        RPM for 8 sec waves); and,

    2. the other problem is that each
        cycle starts from zero movement
        increasing to max movement
        then ends with zero movement
        so the generating stroke cycle is
        not at contiuous speed and each
        cycle starts from a dead stop
        speed point.


The voltage created by the generator is important because it is directly related to the gauge of wire in the coils with respect to the amperage that the generator can sustain before burning out.    more

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