| Author |
Message |
Dejan Uzelac
Guest
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 Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Power supply design |
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Hi.
I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
THANX
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John Woodgate
Guest
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| Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Re: Power supply design |
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I read in sci.electronics.design that Dejan Uzelac
<uzelac@optushome.com.au> wrote (in <420acba2$0$1022$afc38c87@news.optus
net.com.au>) about 'Power supply design', on Thu, 10 Feb 2005:
| Quote: | Hi.
I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
You can't. 9 V x 1 A is 9 watts. 5 V x 2 A is 10 watts. You can't get |
more out than you put in.
The best thing to do is to buy a 5 V 2 A adapter.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk |
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Joel Kolstad
Guest
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| Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Re: Power supply design |
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"Dejan Uzelac" <uzelac@optushome.com.au> wrote in message
news:420acba2$0$1022$afc38c87@news.optusnet.com.au...
| Quote: | I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
|
Standard buck switching power supply from the likes of Linear Technology,
TI, Maxim, National Semiconductor, etc.
You might come up a little shy on the output side, though -- you're asking
for 90% efficiency in the conversion, and this is high enough that -- while
quite doable -- you will have to pay careful attention to where your losses
are. Using something like the National Semi. 'simple switchers' probably
won't cut it. (Although I expect they would readily get you at least 80%
conversion efficiency.)
---Joel Kolstad
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Spehro Pefhany
Guest
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| Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Re: Power supply design |
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On Wed, 9 Feb 2005 18:51:43 -0800, the renowned "Joel Kolstad"
<JKolstad71HatesSpam@Yahoo.Com> wrote:
| Quote: | "Dejan Uzelac" <uzelac@optushome.com.au> wrote in message
news:420acba2$0$1022$afc38c87@news.optusnet.com.au...
I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
Standard buck switching power supply from the likes of Linear Technology,
TI, Maxim, National Semiconductor, etc.
You might come up a little shy on the output side, though -- you're asking
for 90% efficiency in the conversion..
|
More like 111% ;-)
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com |
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Guest
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| Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Re: Power supply design |
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|
Dejan Uzelac wrote:
| Quote: | Hi.
I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
THANX
|
Can't be done. Your adapter supplies 9W and you want to supply 10W. As
someone said, it would need to over 100% efficiency which is
impossible. |
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Mark
Guest
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| Posted:
Thu Feb 10, 2005 11:09 pm Post subject:
Re: Power supply design |
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|
"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:ET3kC6BDcxCCFwyb@jmwa.demon.co.uk...
| Quote: | I read in sci.electronics.design that Dejan Uzelac
uzelac@optushome.com.au> wrote (in <420acba2$0$1022$afc38c87@news.optus
net.com.au>) about 'Power supply design', on Thu, 10 Feb 2005:
Hi.
I have an adapter with an output of 9V 1A DC adapter.
I need to convert this to 5V, 2A?
Any idea how I can make a little power supply circuit or something to
achieve this?
You can't. 9 V x 1 A is 9 watts. 5 V x 2 A is 10 watts. You can't get
more out than you put in.
The best thing to do is to buy a 5 V 2 A adapter.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
|
Or, he could post his request on alt.energy.over-unity. They can help him
there. |
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