Maybe probably NOT. A synchronous non-isolated DC-DC buck converter will act as a boost in reverse if voltage is applied to its output (unless the designer has taken adequate protections against it), but the reverse 'output' is unregulated; it gets limited only by the weakest component when it fails. Most other topologies will spectacularly do nothing. Isolated converters can usually withstand being biased at their output. Most EV if not all DC/DC's are of this topology and/or have another means to prevent reverse current flow. But you won't get what you're after.
How big a motor? One cheap, easy option might be to use a 'modified sine' (read: rectangular wave) inverter with a diode and a large capacitor to rectify its output. Just beware this gives you 170V instead of 120. -Ben On Apr 28, 2014, at 9:01 PM, Michael Ross <[email protected]> wrote: > Maybe, probably. > > You can do whatever you need to do as long as you can accept the > inefficiency that comes with it, and the smoke that gets out. > > If the current is alternating (AC) there are both step up and step down > transformers. (they don't work with DC) > > If the current is constant (DC) you can convert or invert. > > You can also go from low AC to high DC, or high DC to low AC. > > You have to be careful how you language this stuff, just like when you buy > from China you have to worry a little if they mean what you thing they > mean. I am not sure I know what you mean. > > If you want to talk about specific part numbers and specs of converters and > transformers then you can get a better answer. > > Your first question: > "What happens if you apply 12 volts to the output side, will that produce > 120 to 140 volts on the input side?" > > I assume you mean 12VDC and 120VAC. The answer is no if it is a > transformer with a bridge rectifier output. If you meant 12VAC and120VAC - > a 10:1 transformer goes both ways. > > If you meant some sort of electronic converter hardware - like a power > supply that takes in wall current and puts out 12VDC, then you cannot run > that backwards. > > DC to DC converters - you want to read the spec sheet. I would hesitate if > there are labels saying INPUT, and OUTPUT. The implication there is quite > clear. If they do not say that, then your guess as good as mine. > > Or you can hook them up backwards (using eye protection and with your fire > extinguishers handy) and use you meter to see. > > > > > On Mon, Apr 28, 2014 at 8:24 PM, Peter Eckhoff <[email protected]> wrote: > >> The converters that I see for EV applications have the output voltage at >> 12 volts. >> >> What happens if you apply 12 volts to the output side, will that produce >> 120 to 140 volts on the input side? or do you need a converter >> specifically designed to go the other way? >> >> The idea is to take a 12 volt (or 24 volt) battery with high amphrs and >> use the electronics to produce 120 volts at a tenth of the battery's rated >> amphrs to run a 120 volt DC motor using lithium based batteries. >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/ >> attachments/20140428/6fac4950/attachment.htm> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ >> group/NEDRA) >> >> > > > -- > Put this question to yourself: should I use everyone else to attain > happiness, or should I help others gain happiness? > *Dalai Lama * > > Tell me what it is you plan to do > With your one wild and precious life? > Mary Oliver, "The summer day." > > To invent, you need a good imagination and a pile of junk. > Thomas A. > Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> > > A public-opinion poll is no substitute for thought. > *Warren Buffet* > > Michael E. Ross > (919) 550-2430 Land > (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone > (919) 631-1451 Cell > (919) 513-0418 Desk > > [email protected] > <[email protected]> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140428/744735eb/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
