|
|
|
| possibly a little off topic for you guys but please humour me.
i've got this electrical device which requires a 5 volt input and 2A max
supply. what the hell does the max mean?? can i use a supply which provides
less current?? in general how important is it to match an exact power supply
for a component? for instance would the above device run fine with a 6 V 2A
supply?
cheers
| |
| JohnR66 2005-07-24, 9:03 pm |
| "Phil" <pra02kfk@sheffield.ac.uk> wrote in message
news:t8pEe.4166$YL5.734@newsfe2-win.ntli.net...
> possibly a little off topic for you guys but please humour me.
> i've got this electrical device which requires a 5 volt input and 2A max
> supply. what the hell does the max mean?? can i use a supply which
> provides
> less current?? in general how important is it to match an exact power
> supply
> for a component? for instance would the above device run fine with a 6 V
> 2A
> supply?
>
> cheers
>
>
5 volts may signify TTL logic circuits an it will need a regulated voltage.
The supply must be capable of 2 amperes or more current.
John
| |
|
|
"Phil" <pra02kfk@sheffield.ac.uk> wrote in message
news:t8pEe.4166$YL5.734@newsfe2-win.ntli.net...
> possibly a little off topic for you guys but please humour me.
> i've got this electrical device which requires a 5 volt input and 2A max
> supply. what the hell does the max mean?? can i use a supply which
provides
> less current?? in general how important is it to match an exact power
supply
> for a component? for instance would the above device run fine with a 6 V
2A
> supply?
>
> cheers
>
Supply should be 5 volts +- 10% and more than 2 amps, like 2 to 5 amps.
You can always use the "try it, fry it" method of electronics design.
| |
|
| thanks both. will haveto try the "try and fry" i guess. cheers
"Sue" <invalid@spamless.com> wrote in message
news:42e2f4eb$0$59752$892e7fe2@authen.white.readfreenews.net...
>
> "Phil" <pra02kfk@sheffield.ac.uk> wrote in message
> news:t8pEe.4166$YL5.734@newsfe2-win.ntli.net...
> provides
> supply
> 2A
>
> Supply should be 5 volts +- 10% and more than 2 amps, like 2 to 5 amps.
>
> You can always use the "try it, fry it" method of electronics design.
>
>
| |
| Palindr☻me 2005-07-24, 9:03 pm |
| Phil wrote:
> thanks both. will haveto try the "try and fry" i guess. cheers
You may want to consider using a power supply intended for a
PC. They are very cheap (I pay about 1GBP each for them) and
have a stabilised 5 volts output (amongst others).
There are some potential snags - some supplies need a
minimum load* and ATX supplies are more complicated to
switch on and off. So maybe an AT supply would be a better
choice.
* Your load is /probably/ going to be enough - but it
depends on the /minimum/ load that your device applies, not
the maximum. If it doesn't work, you may need to stick an
extra load on - say a one ohm five watt resistor. Without
this minimum load, the power supply won't run properly - a
feature of many switch-mode power supplies.
HTH
Sue - another one, I'm afraid.
> "Sue" <invalid@spamless.com> wrote in message
> news:42e2f4eb$0$59752$892e7fe2@authen.white.readfreenews.net...
>
>
>
>
| |
|
| an interesting idea but this is a little beyond my electrical know-how. i'll
speak to one of my boffin mates to see if he can do what you suggest.
cheers.
P.
"Palindrâ~»me" <sb382638@hotmail.com.invalid> wrote in message
news:11e6q1jpaggisb4@corp.supernews.com...[color=darkred]
> Phil wrote:
>
>
> You may want to consider using a power supply intended for a
> PC. They are very cheap (I pay about 1GBP each for them) and
> have a stabilised 5 volts output (amongst others).
>
> There are some potential snags - some supplies need a
> minimum load* and ATX supplies are more complicated to
> switch on and off. So maybe an AT supply would be a better
> choice.
>
> * Your load is /probably/ going to be enough - but it
> depends on the /minimum/ load that your device applies, not
> the maximum. If it doesn't work, you may need to stick an
> extra load on - say a one ohm five watt resistor. Without
> this minimum load, the power supply won't run properly - a
> feature of many switch-mode power supplies.
>
>
>
> HTH
> Sue - another one, I'm afraid.
>
>
>
max[color=darkred]
V[color=darkred]
| |
| Palindr☻me 2005-07-24, 9:03 pm |
| Palindr=E2=98=BBme wrote:
> Phil wrote:
>=20
>=20
>=20
> You may want to consider using a power supply intended for a PC. They=20
> are very cheap (I pay about 1GBP each for them) and have a stabilised 5=
=20
> volts output (amongst others).
>=20
> There are some potential snags - some supplies need a minimum load* and=
=20
> ATX supplies are more complicated to switch on and off. So maybe an AT =
> supply would be a better choice.
>=20
> * Your load is /probably/ going to be enough - but it depends on the=20
> /minimum/ load that your device applies, not the maximum. If it doesn't=
=20
> work, you may need to stick an extra load on - say a one ohm five watt =
> resistor. Without this minimum load, the power supply won't run properl=
y=20
> - a feature of many switch-mode power supplies.
Oops! Sorry - should have been a five ohm, five watt=20
resistor. Which you can make using five one ohm one watt=20
resistors.
--=20
Sue
| |
| phil-news-nospam@ipal.net 2005-07-25, 10:21 am |
| On Sun, 24 Jul 2005 12:58:54 +0100 Palindr?me <sb382638@hotmail.com.invalid> wrote:
| Palindr?me wrote:
|
|> Phil wrote:
|>
|>> thanks both. will haveto try the "try and fry" i guess. cheers
|>
|>
|> You may want to consider using a power supply intended for a PC. They
|> are very cheap (I pay about 1GBP each for them) and have a stabilised 5
|> volts output (amongst others).
|>
|> There are some potential snags - some supplies need a minimum load* and
|> ATX supplies are more complicated to switch on and off. So maybe an AT
|> supply would be a better choice.
|>
|> * Your load is /probably/ going to be enough - but it depends on the
|> /minimum/ load that your device applies, not the maximum. If it doesn't
|> work, you may need to stick an extra load on - say a one ohm five watt
|> resistor. Without this minimum load, the power supply won't run properly
|> - a feature of many switch-mode power supplies.
|
| Oops! Sorry - should have been a five ohm, five watt
| resistor. Which you can make using five one ohm one watt
| resistors.
Or with five 25 ohm 1 watt resistors.
--
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| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
| (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
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