velz=v1*(z2/zp)^pex[isc]  p=pex[isc]

velm=vo/[Zp^p(H2-H1)(p+1)] [H2^(p+1)-H1^(p+1)]    vo @ Zp known +

     |                  .
     |                  .
     |                  .
     |                 .              H1,H2 or H2,H1
     |                 .
     |                .
     |                .
  V  |               .:
     |              .::              See velm.txt for examples
     |             .:::
     |           ..::::
     |         ..::::::
     |  vo   ..::::::::
     |   +... :::::::::
     |...     :::::::::
      -------------------------------
     0   Zp   H1      H2


     |                  .
     |                  .
     |                  .
     |                 .
     |                 .
     |                .
     |                .
  V  |               .:
     |              .::
     |           vo.:::
     |           .+::::
     |         ..::::::
     |       ..::::::::
     |   .... :::::::::
     |...     :::::::::
      -------------------------------
     0        H1  Zp  H2



     |                  .
     |                  +vo
     |                  .
     |                 .
     |                 .
     |                .
     |                .
  V  |               .:
     |              .::
     |             .:::
     |           ..::::
     |         ..::::::
     |       ..::::::::
     |   .... :::::::::
     |...     :::::::::
      -------------------------------
     0        H1      H2 Zp



     |                  .
     |                  +vo
     |                  .
     |                 .
     |                 .
     |                .
     |                .
  V  |               .:
     |              .::
     |             .:::
     |           ..::::
     |         ..::::::
     |       ..::::::::
     |   .... :::::::::
     |...     :::::::::
      -------------------------------
     0        H2      H1 Zp