AC, DC, or what?

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Subject Author Date AC, DC, or what? SteveB 03-21-2008  Re: AC, DC, or what? Tim Wescott 03-21-2008  Re: AC, DC, or what? SteveB 03-21-2008  Re: AC, DC, or what? Grant Erwin 03-21-2008  Re: AC, DC, or what? Bob F 03-21-2008  Re: AC, DC, or what? Richard Smith 03-21-2008  Re: AC, DC, or what? Bob La Londe 03-21-2008  Re: AC, DC, or what? Richard Smith 03-21-2008  Re: AC, DC, or what? Martin H. Eastb... 03-21-2008
Posted by SteveB on March 21, 2008, 1:41 am Please log in for more thread options Now that my welder is running, I have a question about running grinders and such. The manual says 115v. DC power receptacle, which looks like the three pronged standard receptacles, like in a house. They are rated at 15a. in the manual. I put my little AC tester on there, and it came lit up the 110v. light, so I used my AC Makita stringer brush to buff up some 7018 passes. About 30 seconds, a minute tops. IIRC, I seem to remember discussions about using DC tools on these, or not to use AC, as they burned out, or whatever it was. What's the deal? Do I need to go buy special DC tools to use on this? Just thought I'd ask before I fry something. If I haven't already ..................... Steve Posted by Tim Wescott on March 21, 2008, 12:47 am Please log in for more thread options SteveB wrote: > Now that my welder is running, I have a question about running grinders and > such. The manual says 115v. DC power receptacle, which looks like the three > pronged standard receptacles, like in a house. They are rated at 15a. in > the manual. I put my little AC tester on there, and it came lit up the > 110v. light, so I used my AC Makita stringer brush to buff up some 7018 > passes. About 30 seconds, a minute tops. IIRC, I seem to remember > discussions about using DC tools on these, or not to use AC, as they burned > out, or whatever it was. What's the deal? Do I need to go buy special DC > tools to use on this? > > Just thought I'd ask before I fry something. If I haven't already > ..................... > > Steve > > If it really is DC: Tools with universal motors will be OK, probably. If it's got brushes showing, and it's designed to plug into an AC outlet, it's a universal motor (probably). Electronics with transformers will FRY. I would expect a popped fuse (or irreplaceable fuse-like thing in consumer electronics), so probably no interesting fires to write about. Dunno what would happen if you plug a nice expensive super-gamer PC in there -- don't come crying to me if you do and break it. If you have a voltmeter measure the DC voltage and the AC voltage. If it's really a DC thing then the voltmeter will read DC (and possibly not AC, although no promises). An AC outlet would read little or no DC. If you can see the neon bulb in your AC tester, look to see if both of the the little rods inside are lit, or only one. Only one of them ever lights at one time (I think it's the + side, but I won't promise), so if it's DC only one will light ever, while if it's AC they'll switch back and forth at 60Hz and you'll think they're both lit. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html Posted by SteveB on March 21, 2008, 3:43 am Please log in for more thread options > If it really is DC: Sez so in the manual. > > Tools with universal motors will be OK, probably. If it's got brushes > showing, and it's designed to plug into an AC outlet, it's a universal > motor (probably). I hate that word. And "should." > > Electronics with transformers will FRY. I would expect a popped fuse (or > irreplaceable fuse-like thing in consumer electronics), so probably no > interesting fires to write about. This is going to be for grinders, drills, sawzalls, die grinders, and the like. > > Dunno what would happen if you plug a nice expensive super-gamer PC in > there -- don't come crying to me if you do and break it. I try not to play Martian Laser Gonzo Blondes on my laptop at remote muddy sites. Even in the cab with the windows rolled up and steamy. ;-) > > If you have a voltmeter measure the DC voltage and the AC voltage. If > it's really a DC thing then the voltmeter will read DC (and possibly not > AC, although no promises). An AC outlet would read little or no DC. My electrician buddy is visiting this weekend. I'll have him check it out. Although last time he fried my multimeter testing something. > > If you can see the neon bulb in your AC tester, look to see if both of the > the little rods inside are lit, or only one. Only one of them ever lights > at one time (I think it's the + side, but I won't promise), so if it's DC > only one will light ever, while if it's AC they'll switch back and forth > at 60Hz and you'll think they're both lit. Think that's what I have now you describe it. I'll look at it a litle closer. It was a buck at a yard sale. Probably $.99 originally at the Dollar Store. > > -- > > Tim Wescott Steve Posted by Grant Erwin on March 21, 2008, 2:22 am Please log in for more thread options SteveB wrote: > > >>If it really is DC: > > > Sez so in the manual. > > >>Tools with universal motors will be OK, probably. If it's got brushes >>showing, and it's designed to plug into an AC outlet, it's a universal >>motor (probably). > > > I hate that word. And "should." All small grinders, drill motors, etc. will work just fine on DC, Steve. They are actually a kind of DC motor which will work on AC, called a "universal motor". That's why welders sometimes have DC outlets on them. Grant Posted by Bob F on March 21, 2008, 2:38 am Please log in for more thread options > SteveB wrote: > >> >> >>>If it really is DC: >> >> >> Sez so in the manual. >> >> >>>Tools with universal motors will be OK, probably. If it's got brushes >>>showing, and it's designed to plug into an AC outlet, it's a universal motor >>>(probably). >> >> >> I hate that word. And "should." > > All small grinders, drill motors, etc. will work just fine on DC, Steve. > They are actually a kind of DC motor which will work on AC, called a > "universal motor". That's why welders sometimes have DC outlets on them. Even those with variable speed, or "slow start"? I would think not.