You may wish to consider constant power regulation. It is certainly more
complex, but it can provide you the fastest blots without the risk of
exceeding voltage or current.
A chip such as the LT1618 could be used, but it may be more desirable to use
a DAQ board and a program such as LabVIEW or VisualBasic. Such a system
would allow you to write a program with incredible flexibility. A well
written program might allow you to enter current, voltage, and temperature
limits. It can even stop or change some behavior when a marker reaches a
location.
Good luck! By the way, I am unemployed if anyone needs an inexpensive EE in
one's lab!
Dan
