Can a 120Vac corded grinder or other tools run on DC?

[markz]

I was thinking instead of buying expensive portable cordless tools that runs off the wall outlet at 120Vac and 50-60Hz, couldnt corded tools run off 120Vdc?

From what I gather on the interweb, if its a variable speed its ac only. If its on/off it can be run on dc.
Now my Mastercraft Rotary is an on/off switch, but a variable speed dial.

 

[amberwolf]

You'd have to see what it's internals are like. Most (older; I rarely get new stuff) powertools I've opened up use "universal" motors, which run on either AC or DC. (usually brushed series-wound non-permanent-magnet motors).

If it uses an electronically-controlled motor, then it depends on what those controls will work off of--they might be like many wallwarts and laptop PSUs, that will run off DC or AC (though not usually at their full power rating on DC, because only half the input diodes are able to be used).


There is no cut-and-dried way to tell without checking the internals or trying it. Just because its' variable speed doesn't mean it can't be used on DC instead.

 

[liveforphysics]

It's possible it won't work, but most every human held power tool I've tested on DC worked perfectly.

Stay away from air compressors and table saws and other big stuff that has big motors, they are rarely universal motors after they get so large.