> A cap big enough should be able to handle that. Not sure if I did my math right, but for 2 seconds at 2W (beaglebone will be booting), and assuming his 24V to 5V regulator can regulate with an input voltage all the way down to 12V, that's around 20mF. I guess that's doable with $$$.
It wouldn't be as simple as connecting the cap to the accessories line, since this would absolutely destroy your relay contacts from the inrush in charging this gigantic cap from 0V. And, you would have to throw a diode in so you didn't power *all* of your accessories with this cap. On Tue, Nov 5, 2013 at 9:15 PM, Wilfredo Nieves <[email protected]>wrote: > Not necessarily , my car is a 95 3kgt and it starts within 1-2 seconds of > turning it over. A cap big enough should be able to handle that. As for the > 24v idk how I didn't catch that, but then again who knows it is possible. > > -Wil > On Nov 5, 2013 9:30 PM, "Brandon I" <[email protected]> wrote: > >> > I've connected beagleboneblack to my car power supply with 24V to 5V >> step down. >> >> 24V "power supply" in a car? If this means you're this from the >> accessories circuit, you're doomed. Accessories are turned off while the >> car is being started, and a cap won't be enough to power the beaglebone, >> since they stay off as long as you're turning the engine. Another problem >> is, you'll corrupt the filesystem with an out-of-the-box beaglebone. You'll >> *have to* use a read only file system. >> >> You could tie the beaglebone directly to the battery (with a fuse of >> course) and use some circuit to monitor when to turn it on and off. >> >> On Tuesday, November 5, 2013 9:24:49 AM UTC-8, Wilfredo Nieves wrote: >>> >>> I think you should be fine as long as you don't use a value that is too >>> high or too low. Too high may cause problems with rise time and too low may >>> not keep enough power supplied for the board to stay powered up. Also caps >>> aren't like batteries, the charge almost instantaneously where as batteries >>> need time to fully charge so as long as you can get the cap charged fast >>> enough the board should power up without any problems. >>> >>> -Wil >>> On Nov 5, 2013 8:27 AM, "satya gowtham kudupudi" <[email protected]> >>> wrote: >>> >>>> Thank you. I will give a try. As per the post here >>>> https://groups.google.com/forum/#!msg/beagleboard/ >>>> aXv6An1xfqI/mURD3LfQ5dMJ? the power source should have proper rise >>>> time. I'm afraid a capacitor will increase the rise time. Any way I'll give >>>> a try. >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "BeagleBoard" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> For more options, visit https://groups.google.com/groups/opt_out. >>>> >>> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> >> For more options, visit https://groups.google.com/groups/opt_out. >> > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to a topic in the > Google Groups "BeagleBoard" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/beagleboard/5toeq-9pcfU/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
