Author: ClueLessDate: 02:54 21-05-08
|
|
Hi All
I have a setup with 8051 micro controller and I want to provide a
battery backup so that when power fails the micro continues to work.
Only the micro needs to work and other peripherals need not.
What will be the minimum circuitry and what is the minimum voltage
required to keep this micro up?
--
Thanks for your time and attention
ClueLess
|
|
|
|
Author: Rich GriseDate: 13:52 21-05-08
|
|
On Wed, 21 May 2008 14:54:47 +0800, ClueLess wrote:
> Hi All
>
> I have a setup with 8051 micro controller and I want to provide a
> battery backup so that when power fails the micro continues to work.
> Only the micro needs to work and other peripherals need not.
>
> What will be the minimum circuitry
Two diodes, for isolation.
> and what is the minimum voltage
> required to keep this micro up?
That depends on which model of micro - check the data sheet for
a "power down" or "sleep" mode or the like; the data sheet knows
all. ;-)
Good Luck!
Rich
|
|
|
|
Author: Lord GarthDate: 15:53 21-05-08
|
|
|
|
|
|
Author: ClueLessDate: 02:25 22-05-08
|
|
On Wed, 21 May 2008 17:52:38 GMT, Rich Grise <rich@example.net> wrote:
>Two diodes, for isolation.
Say, how do you connect them? Is one not enough?
--
Thanks for your time and attention
ClueLess
|
|
|
|
Author: Rich GriseDate: 15:11 22-05-08
|
|
On Wed, 21 May 2008 14:53:56 -0500, Lord Garth wrote:
> "Rich Grise" <rich@example.net> wrote in message
>> On Wed, 21 May 2008 14:54:47 +0800, ClueLess wrote:
>
> "model"
>> Good Luck!
>> Rich
>
> The spelling police are going to get you!!!
What? How would _you_ spell "model"?
http://www.google.com/search?q=define%3Amodel
Thanks,
Rich
|
|
|
|
Author: Rich GriseDate: 15:12 22-05-08
|
|
On Thu, 22 May 2008 14:25:47 +0800, ClueLess wrote:
> On Wed, 21 May 2008 17:52:38 GMT, Rich Grise <rich@example.net> wrote:
>
>>Two diodes, for isolation.
>
> Say, how do you connect them? Is one not enough?
That depends on if you're worried about proper current-sharing; this
isn't my forte, so hopefully someone can give a more comprehensive
answer - OP asked for the "simplest", and that came to my simple mind. ;-)
Thanks,
Rich
|
|
|
|
Author: John FieldsDate: 15:30 22-05-08
|
|
On Thu, 22 May 2008 19:12:39 GMT, Rich Grise <rich@example.net> wrote:
>On Thu, 22 May 2008 14:25:47 +0800, ClueLess wrote:
>
>> On Wed, 21 May 2008 17:52:38 GMT, Rich Grise <rich@example.net> wrote:
>>
>>>Two diodes, for isolation.
>>
>> Say, how do you connect them? Is one not enough?
>
>That depends on if you're worried about proper current-sharing; this
>isn't my forte, so hopefully someone can give a more comprehensive
>answer - OP asked for the "simplest", and that came to my simple mind. ;-)
+--[DIODE>]--+--[<DIODE]--+
|+ | |+
[SUPPLY] [MICRO] [BAT]
| | |
+------------+------------+
The voltage from the supply should be high enough to reverse-bias the
battery-side diode.
JF
|
|
|
|
Author: Lord GarthDate: 16:03 22-05-08
|
|
"Rich Grise" <rich@example.net> wrote in message
news:pan.2008.05.22.19.11.10.923988@example.net...
> On Wed, 21 May 2008 14:53:56 -0500, Lord Garth wrote:
>> "Rich Grise" <rich@example.net> wrote in message
>>> On Wed, 21 May 2008 14:54:47 +0800, ClueLess wrote:
>>
>> "model"
>>> Good Luck!
>>> Rich
>>
>> The spelling police are going to get you!!!
>
> What? How would _you_ spell "model"?
> http://www.google.com/search?q=define%3Amodel
>
>
Rich, that was another worker in this office screwing with my
computer when I was making a pit stop. I'm now convinced
he is lesdexic or just stupid!
;-)
PS. I'll try to remember to lock the keyboard when I'm out of sight
so that won't happen again.
|
|
|
|
Author: EeyoreDate: 19:58 22-05-08
|
|
ClueLess wrote:
> what is the minimum voltage required to keep this micro [8051] up?
Varies with manufacturer and specific model. Certainly as low as 2.7V
IIRC with some Philips (NXP) parts.
Graham
|
|
|
|
Author: ClueLessDate: 06:09 23-05-08
|
|
On Thu, 22 May 2008 14:30:49 -0500, John Fields
<jfields@austininstruments.com> wrote:
> +--[DIODE>]--+--[<DIODE]--+
> |+ | |+
> [SUPPLY] [MICRO] [BAT]
> | | |
> +------------+------------+
>
>The voltage from the supply should be high enough to reverse-bias the
Much thanks for the response. That goes to the others too.
--
Thanks for your time and attention
ClueLess
|
|
|
|
Author: Rich GriseDate: 18:04 23-05-08
|
|
On Thu, 22 May 2008 15:03:55 -0500, Lord Garth wrote:
> "Rich Grise" <rich@example.net> wrote in message
> news:pan.2008.05.22.19.11.10.923988@example.net...
>> On Wed, 21 May 2008 14:53:56 -0500, Lord Garth wrote:
>>> "Rich Grise" <rich@example.net> wrote in message
>>>> On Wed, 21 May 2008 14:54:47 +0800, ClueLess wrote:
>>>
>>> "model"
>>>
>>> The spelling police are going to get you!!!
>>
>> What? How would _you_ spell "model"?
>> http://www.google.com/search?q=define%3Amodel
>>
> Rich, that was another worker in this office screwing with my
> computer when I was making a pit stop.
OK, no harm, no foul. :-)
Cheers!
Rich
|
|
|
|
1 |
