From: Dorian Levy <[email protected]> Reply-To: <[email protected]> Date: Wednesday, March 5, 2014 at 11:13 AM To: <[email protected]> Subject: Re: [beagleboard] Powering the BBB
> 11.7V supply shouldn't be a problem because it can take up to 25V, but I'll > try a heat sink and see if that helps. Gerald is exactly right about this. You must consider all the parameter of the regulator, not just one. The data sheet specifies the heat that can be dissipated with and without a heat sink. Look at the operating envelop. BTW, you should be using a switching regulator as it is much more efficient and won¹t generate that much heat. Regards, John > > > > On Wed, Mar 5, 2014 at 2:05 PM, Gerald Coley <[email protected]> wrote: >> Because the regulator is going into thermal limit due to excessive heat >> dissipation. Make the 11.7V supply say 8V and it will run longer. The hole in >> the tab of the regulator is for the heat sink. >> >> Now, if the regulator is putting out 7V, then it could be the board. >> >> Gerald >> >> >> On Wed, Mar 5, 2014 at 1:02 PM, Dorian Levy <[email protected]> wrote: >>> Because the IC can't provide the required current without a heat sink? Or >>> because the BBB is going into thermal protection? A little insight into why >>> you would expect that would be appreciated." >>> >>> On Mar 5, 2014 1:43 PM, "Gerald Coley" <[email protected]> wrote: >>>> OK. Then what you are describing as your issue, i would expect to happen. >>>> >>>> Gerald >>>> >>>> >>>> >>>> On Wed, Mar 5, 2014 at 12:37 PM, Dorian Levy <[email protected]> wrote: >>>>> >>>>> No heatsink 5V >>>>> >>>>> On Mar 5, 2014 11:13 AM, "Gerald Coley" <[email protected]> wrote: >>>>>> Are you using a heatsink? Voltage? >>>>>> >>>>>> Gerald >>>>>> >>>>>> >>>>>> >>>>>> On Wed, Mar 5, 2014 at 10:07 AM, Dorian Levy <[email protected]> >>>>>> wrote: >>>>>>> Addicore 5V 1.5A Positive Voltage Regulator L7805CV >>>>>>> >>>>>>> >>>>>>> On Wed, Mar 5, 2014 at 10:52 AM, Gerald Coley <[email protected]> >>>>>>> wrote: >>>>>>> That particular regulator can have different pinouts. I have been bitten >>>>>>> before. So double check that based on the supplier. >>>>>>> >>>>>>> What voltage are you seeing on the output? I believe the best you can >>>>>>> get out of that regulator without a big heatsink is maybe 500mA which >>>>>>> is borderline for the BBB. You are dropping 6.7V across the regulator. >>>>>>> >>>>>>> Gerald >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Wed, Mar 5, 2014 at 8:57 AM, Dorian Levy <[email protected]> >>>>>>> wrote: >>>>>>> On Mar 4, 2014 7:42 PM, "Gerald Coley" <[email protected]> wrote: >>>>>>> Can you share a schematic with me? I can't visualize what you are doing. >>>>>>> >>>>>>> Gerald >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Tue, Mar 4, 2014 at 5:05 PM, Dorian Levy <[email protected]> >>>>>>> wrote: >>>>>>> I am building a robot that uses an 11.7V battery. I tried attaching a >>>>>>> 5V regulator to the T5(+)/T8(-) (pins with the T6(SENSE) bridged to T5 >>>>>>> and a 10K resistor between T8(TS) and ground. The board only stays on >>>>>>> for about thirty seconds then shuts down. Is it because of the TS? What >>>>>>> type of thermistor does it use? Or should I try to use the barrel jack >>>>>>> since it's not directly connected to a battery? >>>>>>> -- >>>>>>> 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/-Zb4VUlh5Mg/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. >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> 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/-Zb4VUlh5Mg/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. >>>>>> >>>>>> >>>>>> -- >>>>>> 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/-Zb4VUlh5Mg/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. >>>> >>>> >>>> -- >>>> 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/-Zb4VUlh5Mg/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. >> >> >> -- >> 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/-Zb4VUlh5Mg/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. -- For more options, visit http://beagleboard.org/discuss --- You received this message 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