> [What is the typical drive voltage for an impact
> print head ?]
> The printer heads that you find on dot matrix printers that use a
> ribbon ....
> Gus

Sufficient unto the morrow is the voltage thereof.

Using an oscilloscope in a specific case probably helps.

BUT note that inductive devices that require rapid response are often
current driven. ie the potential voltage (no pun intended) is high but
the current is limited. This way you get a much more rapid current
rise. This can be achieved either with as "proper" current source or
more simply by using a high voltage supply and a large series
resistor. "High" and "large" are relative to the given application.

Inductive time constant = L/r. By using a perfect current source you
get infinite R (and infinite voltage initially). By adding a series R
of say 10 x the inductor's resistance and a voltage 11 x the desired
final voltage you reduce time constant by ~ 10 times.

Note that Richard Prosser's original 2 transistor 0relay driver which
formed the basis for the "Black Regulator" effectively provided a
crude but effective current source relay driver .


        R
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