switching power supply
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Posts: 46,084
Unless the switcher you have is extremely old technology or homemade...you
shouldn't have to draw any current from either voltage output for it to
operate correctly. It is true that the supply is more efficient when loaded,
but that will not prevent it from working with no load .
[noparse][[/noparse]Non-text portions of this message have been removed]
shouldn't have to draw any current from either voltage output for it to
operate correctly. It is true that the supply is more efficient when loaded,
but that will not prevent it from working with no load .
[noparse][[/noparse]Non-text portions of this message have been removed]
Comments
need a "minimum" load to fall into regulation.
You'll get output, but with very little load,
the voltage may be too high, on the 5V output.
Russ
> Unless the switcher you have is extremely old technology or homemade...you
> shouldn't have to draw any current from either voltage output for it to
> operate correctly. It is true that the supply is more efficient when loaded,
> but that will not prevent it from working with no load .
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
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it without some load. For me I add an old hard drive to one of the plugs
which adds some load to both +5 and +12.
Bucky
Original Message
From: RussBassani@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yokl6KzVBgcJtvoVDw2hRL9j0b-0pYPa-8zgAODmT2i1yqWt4djxt6pblEy6fMJPja4DKWDfMBVsr0sk]RussBassani@a...[/url
Sent: Saturday, January 25, 2003 7:46 AM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] switching power supply
Just to add my 2 cents, many of these switchers
need a "minimum" load to fall into regulation.
You'll get output, but with very little load,
the voltage may be too high, on the 5V output.
Russ
> Unless the switcher you have is extremely old technology or homemade...you
> shouldn't have to draw any current from either voltage output for it to
> operate correctly. It is true that the supply is more efficient when
loaded,
> but that will not prevent it from working with no load .
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body
> of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
seems like the extreem case of overkill.
Since the BS2 has an onboard voltage regulaor, you do not need to
feed it exactly 5V.
And, since the solenoides just don't care, you can feed them pretty
much anything. Check the specs on the solenoids and then put
togethere an unregulated power supply. a simple transformer, a
rectifier and a couple caps. you could find a wall wart to handle
all that.
then you could pull power off the 12V line thru a 7805 for the
stamp. minimal components, minimal cost
just remember that the output of the caps will be near peak rms so
multiply the xfrmr out by 1.414 to figure DC volts. and you might
loose a little thru the bridge.
If you chose to use the other supply, maybe you could just add a
bunch of LED's. RED to indiace a solenoid is off, and GREEN to
indicate on, and just drive them from the 5V. or just use a couple
resistors for load to make a nice little heater and constant load.
Dave
--- In basicstamps@yahoogroups.com, andrew <manwithapipe@y...> wrote:
> Hello...
>
> Disclaimer: this may seem like a ridiculoso question
> to some, but I'm a beginner...hehe
>
> I have a switching power supply (+5/12A,+12/5A) that
> I'd like to use for a project involving eight
> solenoids, a bsII, and some other junk.
>
> I know that a minimum load needs to pull from 5V so
> that the power supply will source, and I'd like to use
> the supply for all components in the project. However,
> is it dangerous using it with the stamp?
>
> Also, I'm guessing the max sink on the stamp is below
> the min source for the power supply. If I don't have
> any other 5V components, does anyone know of a trick
> to pull off 5V to allow me to source my solenoids.
> Should I get rid of the switching power & use two
> separate supplies? Thanks!
>
>
> --andrew
>
>
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