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

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

I'll assume you're talking about MIG/wirefeed welders?

Tap voltage control is where you have multiple taps on the secondary winding
of the power transformer. By selecting different taps you select a
different voltage. This is the simplest because all you need is a switch
that selects a tap to control the voltage.

A continuously variable voltage control is a potentiometer that adjusts the
voltage much like you adjust the volume on a radio. This requires quite a
bit more circuitry which makes the welder more expensive to operate and
repair and probably more prone to failure simply because of the added
complexity.

I have a Lincoln SP-170T (same as the SP-175T) and it's a multi-tap machine.
I've never used a continuously variable welder so I'm not really qualified
to tell you how much it affects your welds but I've never missed it and
personally I think I'd have more trouble setting it up with the extra
adjustment. :-)

Best Regards,
Keith Marshall


"I'm not grown up enough to be so old!"


"Dan" wrote in message
.com...
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

Taps mean you have a definite number of voltage levels for output.
Continuous allows an infinite number of voltages (between 14.1 and 14.2V,
there is 14.15, and between...). I would hazard a guess that you won't need
an infinite number of taps, that however many the tapped machine has will be
fine.

In a way I guess it's like gears on a bike or car. Sometimes one gear is
too high while the adjecent gear is too low. I'm glad I have a 24 speed
bike.

Tim

--
"I have misplaced my pants." - Homer Simpson | Electronics,
- - - - - - - - - - - - - - - - - - - - - - --+ Metalcasting
and Games: http://webpages.charter.net/dawill/tmoranwms

"Dan" wrote in message
.com...
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

In article , 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



Multiple Tap transformer based MIG welders used to be the most common
type.
They are much simpler to build since you just have a wire come off the
transformer at each voltage required.

The rotary switch just chooses between the taps.

Most modern MIG machines use an electronic voltage control to allow
finer adjustment of your output voltage.
It makes the transformers a lot cheaper to manufacture.

However...
If these infinitely variable transformers were so superior for
everything, why would Miller and Lincoln still be selling a 250 amp
multi-tap transformer MIG machine?

The answer has to do with arc stability.
A multi-tap transformer power supply has a very smooth arc that works
much better for sheet metal than a digitally controlled transformer.
The digitally controlled transformers tend to have a harsher arc.
Lincoln has made progress to improve this and Miller is catching up.

There is enough of a market for them that Miller and Lincoln still
offer the older style machine.