[TheForge] Inverters

[xlch58 at swbell.net]

Generally  the whole point of resistive vs inductive loads for an 
inverter is those designed for "resistive only" generally produce a 
funky AC wave form, or they operate at a nonstandard or unregulated 
frequency.   A resistive load is pretty much unaffected, but an 
"inductive" load is designed to take advantage of the AC wave form at a 
particular frequency.  A standard AC motor operated at the wrong 
frequency for example, will run at a different speed.   If the AC wave 
form is funky, it can cause a motor to overheat.  As far as inverter 
based welders, they have transformers in them.  These transformers may 
or may not tolerate hijinks with the input wave form.   All common 
eletric motors depend on induction to work, but some, so called 
universal motors, are less finicky.  They are called universal because 
they are capable of running on AC or DC.   Many small power tools use 
universal motors.  They will probably operate ok on an inverter designed 
for "resistive" loads. 

Charles

Marc wrote:
> An inductive load is basically a coil of wire - any kind of coil.
> Electrical motors are coils of wire, so they're all inductive loads. OK,
> maybe there are some strange things like electrostatic motors that
> aren't inductive, but I think you get the idea. And non-inverter
> welders, like buzz-boxes, are also inductive, because they've got these
> big transformers in them. 
>
> Inverters also have transformers but I'm not sure if they look
> inductive. There's some transistor circuitry in there that may change
> the characteristics. Also, their transformers are much smaller, as they
> work off a much higher frequency than the 60Hz line, so they will not be
> as inductive as the bigger buzz-box transformers.
>
> And - if you want to get reeeeeeeally technical, all loads have some
> inductance, but things like light bulbs are so low as it doesn't really
> affect anything we care about.
>
> --Marc
>
>
>
> On Sat, 2007-05-26 at 08:55 -0700, Ben Barrett wrote:
>   
>> Well certain [electric] motors are induction-run.... things like
>> lights, most heaters, etc, are resistive... I'm pretty sure the
>> standard arc welder is resistive.  Induction uses EMF from a coil, and
>> often involves pulsation (some frequency, similar to AC [vs DC]) and
>> sometimes higher voltage as well.
>>