An 'adjustable tap' machine has a series of discreet taps for
voltage (or current depending on the machine) Continuous lets you
have an infinite set of voltages. Cheaper machines use the tap
style, more expensive use the continuous.

Continuous is better, it lets you dial in to the 'exact' spot you
want. If you are doing nuclear code work, you gotta have the
best, a hobbist can ususally get by with the tap variety. Keep in
mind that the better welders will have the continuous control, it
is a bit hard to compare them on the basis of voltage control only.

Dan wrote:
Can anyone tell me what the difference is between an "adjustable tap voltage
control" and "continuous full range adjustment of voltage." Also, what
effect does this have on your welds?

Thanks

Dan