7805?

Archiver

I noticed in the boe-bot docs from parallax that they replace the old standby
7805 for a different 5v regulator..

Is there any reason why I couldn't still use one if I separate the power to the
stamp and to the servos?

Thanks

Sean

Archiver

That is the way I am doing it - so no I don't think there is a reason.


richard

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Original Message

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From: Sean Conlon <gnomish1@p...>
To: <basicstamps@egroups.com>
Sent: Tuesday, June 27, 2000 12:26 PM
Subject: [noparse][[/noparse]basicstamps] 7805?


> I noticed in the boe-bot docs from parallax that they replace the old
standby 7805 for a different 5v regulator..
>
> Is there any reason why I couldn't still use one if I separate the power
to the stamp and to the servos?
>
> Thanks
>
> Sean
>
>
>
>
>
>

Archiver

To my knowledge, the reason for the new regulator is that it is a LDO (low
drop out) variety. The original BOE used a 9V battery. The 7805 needs
something like 7V+ to give 5V out. The BOE bot uses 4AA cells 4x1.5 = 6V.
This isn't enough to reliably drive the 7805 and even less if the batteries
weaken. The LDO part only needs a hair more than 5V.

Regards,

Al Williams
AWC
* Pulse input and output with the PAK-VII and PAK-VIII...
http://www.al-williams.com/awce


>

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Original Message

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> From: Sean Conlon [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=XqDoh3vEC9-e0nyJpEpAL5DUkbwdfGJzSaU-T3UtutCnO3LjEYPsyROyGzSCy45_NydFoo1jbZ5xFi8rrO50bP4]gnomish1@p...[/url
> Sent: Tuesday, June 27, 2000 12:26 PM
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] 7805?
>
>
> I noticed in the boe-bot docs from parallax that they replace the
> old standby 7805 for a different 5v regulator..
>
> Is there any reason why I couldn't still use one if I separate
> the power to the stamp and to the servos?
>
> Thanks
>
> Sean
>
>
>
>