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basics | usb output
There are 7 messages in this thread.
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usb output - steve - 2009-09-20 03:00:00
Anyone know how much voltage a Usb port outputs? I am trying to recharge a mp3 player via the port, but it takes too long. So how much would the player require, in terms of volts, amps etc. Thanks Steve
Re: usb output - Ken - 2009-09-20 03:48:00
On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <k...@gmail.com> wrote: > Anyone know how much voltage a Usb port outputs? 5 Volt. Maximum 500 mA. http://en.wikipedia.org/wiki/Usb > I am trying to recharge a mp3 player via the port, > but it takes too long. So how much would the > player require, in terms of volts, amps etc. Depends on the player.
Re: usb output - 2009-09-20 13:27:00
On Sun, 20 Sep 2009 09:48:33 +0200, Ken <k...@telia.com> wrote: >On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <k...@gmail.com> >wrote: > >> Anyone know how much voltage a Usb port outputs? > >5 Volt. Maximum 500 mA. That's if the device can tell the USB port that it requires more than 100ma. Otherwise, consider the safe limit to be 100ma - or use a powered USB hub. > >http://en.wikipedia.org/wiki/Usb > > >> I am trying to recharge a mp3 player via the port, >> but it takes too long. So how much would the >> player require, in terms of volts, amps etc. > >Depends on the player. > Players often use a Lithium-technology battery, which typically is 3.6 or 3.7 volts. Since improperly charged Li batteries can catch fire, charging via the USB connection may be limited for safety. Or the charge circuit may be designedto run from a 9 or 12 volt wall wart... John
Re: usb output - Roger Dewhurst - 2009-09-21 07:06:00
n...@jecarter.us wrote: > On Sun, 20 Sep 2009 09:48:33 +0200, Ken <k...@telia.com> wrote: > >> On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <k...@gmail.com> >> wrote: >> >>> Anyone know how much voltage a Usb port outputs? >> 5 Volt. Maximum 500 mA. > > That's if the device can tell the USB port that it requires more than > 100ma. Otherwise, consider the safe limit to be 100ma - or use a > powered USB hub. > >> http://en.wikipedia.org/wiki/Usb >> >> >>> I am trying to recharge a mp3 player via the port, >>> but it takes too long. So how much would the >>> player require, in terms of volts, amps etc. >> Depends on the player. >> > > Players often use a Lithium-technology battery, which typically is 3.6 > or 3.7 volts. Since improperly charged Li batteries can catch fire, > charging via the USB connection may be limited for safety. Or the > charge circuit may be designedto run from a 9 or 12 volt wall wart... Do all cellular phones run on that voltage? R > > John
Re: usb output - steve - 2009-09-22 10:26:00
On Sep 20, 10:27=A0pm, n...@jecarter.us wrote: > On Sun, 20 Sep 2009 09:48:33 +0200, Ken <ke...@telia.com> wrote: > >On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <kvst...@gmail.com> > >wrote: > > >> Anyone know how much voltage a Usb port outputs? > > >5 Volt. =A0 Maximum 500 mA. > > That's if the device can tell the USB port that it requires more than > 100ma. =A0Otherwise, consider the safe limit to be 100ma - or use a > powered USB hub. > > > > >http://en.wikipedia.org/wiki/Usb > > >> I am trying to recharge a mp3 player via the port, > >> but it takes too long. =A0So how much would the > >> player require, in terms of volts, amps etc. > > >Depends on the player. > > Players often use a Lithium-technology battery, which typically is 3.6 > or 3.7 volts. =A0Since improperly charged Li batteries can catch fire, > charging via the USB connection may be limited for safety. =A0Or the > charge circuit may be designedto run from a 9 or 12 volt wall wart... > > John ---------------------------------------------------------------------------= ----------- Thanks to everyone. I believe this is a cheap player because after charging for three hours, it played only a few minutes. Then it says =91Low Power=92, and shuts down. Steve
Re: usb output - jamesgangnc - 2009-09-22 13:33:00
On Sep 22, 10:26=A0am, steve <kvst...@gmail.com> wrote: > On Sep 20, 10:27=A0pm, n...@jecarter.us wrote: > > > > > > > On Sun, 20 Sep 2009 09:48:33 +0200, Ken <ke...@telia.com> wrote: > > >On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <kvst...@gmail.com> > > >wrote: > > > >> Anyone know how much voltage a Usb port outputs? > > > >5 Volt. =A0 Maximum 500 mA. > > > That's if the device can tell the USB port that it requires more than > > 100ma. =A0Otherwise, consider the safe limit to be 100ma - or use a > > powered USB hub. > > > >http://en.wikipedia.org/wiki/Usb > > > >> I am trying to recharge a mp3 player via the port, > > >> but it takes too long. =A0So how much would the > > >> player require, in terms of volts, amps etc. > > > >Depends on the player. > > > Players often use a Lithium-technology battery, which typically is 3.6 > > or 3.7 volts. =A0Since improperly charged Li batteries can catch fire, > > charging via the USB connection may be limited for safety. =A0Or the > > charge circuit may be designedto run from a 9 or 12 volt wall wart... > > > John > > -------------------------------------------------------------------------= --=AD----------- > > Thanks to everyone. > > I believe this is a cheap player because after charging for three > hours, it played only a few minutes. > > Then it says =91Low Power=92, and shuts down. > > Steve- Hide quoted text - > > - Show quoted text - Sounds like it's battery is shot. How old is it? Rechargable batteries have a limited number of cycles.
Re: usb output - steve - 2009-10-01 09:39:00
On Sep 22, 10:33=A0pm, jamesgangnc <jamesgan...@gmail.com> wrote: > On Sep 22, 10:26=A0am, steve <kvst...@gmail.com> wrote: > > > > > > > On Sep 20, 10:27=A0pm, n...@jecarter.us wrote: > > > > On Sun, 20 Sep 2009 09:48:33 +0200, Ken <ke...@telia.com> wrote: > > > >On Sun, 20 Sep 2009 00:00:53 -0700 (PDT), steve <kvst...@gmail.com> > > > >wrote: > > > > >> Anyone know how much voltage a Usb port outputs? > > > > >5 Volt. =A0 Maximum 500 mA. > > > > That's if the device can tell the USB port that it requires more than > > > 100ma. =A0Otherwise, consider the safe limit to be 100ma - or use a > > > powered USB hub. > > > > >http://en.wikipedia.org/wiki/Usb > > > > >> I am trying to recharge a mp3 player via the port, > > > >> but it takes too long. =A0So how much would the > > > >> player require, in terms of volts, amps etc. > > > > >Depends on the player. > > > > Players often use a Lithium-technology battery, which typically is 3.= 6 > > > or 3.7 volts. =A0Since improperly charged Li batteries can catch fire= , > > > charging via the USB connection may be limited for safety. =A0Or the > > > charge circuit may be designedto run from a 9 or 12 volt wall wart... > > > > John > > > -----------------------------------------------------------------------= ----=AD=AD----------- > > > Thanks to everyone. > > > I believe this is a cheap player because after charging for three > > hours, it played only a few minutes. > > > Then it says =91Low Power=92, and shuts down. > > > Steve- Hide quoted text - > > > - Show quoted text - > > Sounds like it's battery is shot. =A0How old is it? =A0Rechargable > batteries have a limited number of cycles.- Hide quoted text - > > - Show quoted text - ---------------------------------------------------------------------------= ---------------------- It is a cheap, no-name player. I bought it due to the sound quality, which is very good. The retailer says that its better to charge with a wall wart. This wart now takes approx 40 minutes, after which the player says =91battery full=92. Then it plays for about half an hour maximum, and shuts down.