Timeline for How to extract electricity from a permanent magnet generator (PMG) to charge a 48V battery bank?
Current License: CC BY-SA 4.0
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| Jul 19, 2022 at 13:42 | history | migrated | from diy.stackexchange.com (revisions) | ||
| Jul 19, 2022 at 4:13 | comment | added | George Anderson | @Ecnerwal yep. that would be perpetual motion, something snake oil salesman have been selling various devices for many decades, maybe centuries. To an extremely smart friend of mine, I was describing pumped hydro, which uses renewables to pump water into a higher elevation reservoir for later hydro-electric generation. He said why don't they just use the power generated by the hydro to pump it back up? I said, well, that would be perpetual motion. Even though he's extremely bright, I couldn't convince him it was contrary to the laws of physics. sigh | |
| Jul 19, 2022 at 2:54 | comment | added | Ecnerwal | 25 watts in means you'll get less than 25 watts out, period, in this universe. You can make 50,000 volts from a 9V battery with no permanent magnet involved. The physics & math does not alter, power in = power out (but some of the electrical power turns into heat and is "wasted" - still the total adds up and has been repeatedly verified.) Your misunderstanding of what happens in a permanent magnet generator would be "magic" if it wasn't a misunderstanding. Hook the output to the input and have a perpetual motion machine... | |
| Jul 19, 2022 at 2:16 | comment | added | manassehkatz-Moving 2 Codidact | 25W input producing 250V is meaningless if the current < 0.1A. If it is more than 0.1A, sign me up. | |
| Jul 19, 2022 at 2:00 | comment | added | manassehkatz-Moving 2 Codidact | You can create higher voltage at lower current or higher current at lower voltage. On an ongoing basis (there can be storage aspects on the very short term) you can't get more power out than you put in. | |
| Jul 19, 2022 at 1:58 | comment | added | Paul Evans | Small DC motor was not implying insufficient DC power in this instance. What I meant by small DC motor was not an energy hog. The input motor uses about 25 watts of power to spin the generator and give an output of about 250 volts. I thought that was pretty incredible. Thank you for your answer, although it's not really along the lines of what I'm wanting to do here. I'm not trying to create magic out of thin air, but my understanding of a PMG is that you can create more output than input by utilizing the magnets - just an increase from the input. | |
| Jul 19, 2022 at 1:13 | history | answered | Ecnerwal | CC BY-SA 4.0 |