Re: Power supplies in parallel for more current/same voltage?

Daniel Morrow wrote: 
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Bottom posted.

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"Ken Taylor" <ken123@xxxxxxxxxx> wrote in message
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"Gerard Bok" <bok118@xxxxxxxxx> wrote in message
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On Tue, 15 Nov 2005 07:46:39 +1300, "Ken Taylor"
<ken123@xxxxxxxxxx> wrote:


"Gerard Bok" <bok118@xxxxxxxxx> wrote in message
news:4378913b.11322538@xxxxxxxxxxxxxxxxxxxxxx

On Sun, 13 Nov 2005 18:27:45 -0800, "Daniel Morrow"
<videoman@xxxxxxxxxxxx> wrote:


Hi everyone! I am trying to find a cheap way I can increase 

the

current capacity of a power supply by installing fuses to each 

output

of multiple universal power supplies, setting each polarity
correctly, setting each voltage correctly, but in other words


combine

power supplies to get up to 3 amps or more available from the
parallel power supplies, to drive digital cameras. I have


researched

power supply providers and have found no usable/cheap enough 

power

supplies (those dedicated power supplies are very expensive - 

By far the cheapest solution is to buy a single 3 Amp supply.

Be very VERY carefull: it's not uncommon for 3 Amp supplies to
supply a much higher output voltage than the label says.

Wich may well result in a 'final flash' from your camera :-)

What is so unusual about a 3A supply that it's output isn't 

specified

correctly? 

Some supplies are stabilized. Some supplies provide the stated
output voltage (more or less) under the specified load.
And under no or low load a voltage that is much higher.
A digital camera connected to a PSU is unlikely to draw 3 Amps
all the time :-)

Also: some appliances take their input voltage to an internal
stabilizer. While others just supply it to their chips.
Without good knowledge of both the PSU and the camera, it is


easy

to blow the camera.

--
Kind regards,
Gerard Bok

Um, yeah, well I was kinda assuming that by 3A a supply isn't going 

to be

unregulated, but it's a fair comment. Pre-morning tea. :-)

Given that the OP is only after about 3A total, a single 

switch-mode (hence

regulated and stabilized) wall-wart/power-pack is a good option and 


certainly better than trying to connect several up in parallel.

Cheers.

Ken




I am glad I asked before trying it. I have reviewed what you all have
said and realized that it normally isn't a problem (supplying power
to a digital camera) because people almost always just plain use
batteries, and after kicking things around in my head realized I
won't do otherwise (i.e. I will stick to batteries for these 2
cameras), my fathers' pocket camera can run off of a 1300 milliampere
universal so when I transfer the images from the camera to computer
the camera will stay on and not shut off due to low battery levels,
in turn that will keep windows 2000 professional service pack 4 from
crashing etc. (windows 2000 and xp suffer from not being true plug
and play compatible operating systems - if you shut a device off
without telling the operating system to unplug/eject a device through
the windows add/remove hardware wizard the operating system can
crash). The pocket camera can take 40 to 50 minutes to download 1 32
megabyte flash memory card's worth of pictures and at times there are
2 or 3 of those cards to download,


Whoa,40-50 minutes for one 32meg card?
Sounds like that might be your problem -it shouldn't take that long!
Some cards/readers are a bit slower than others,but if it takes that long,something else is probably wrong.
Do you have the correct drivers installed(if needed?),etc?



so if the camera shuts off after 1
I usually have to reboot to do the next, etc.. I would like to just
be able to leave the camera on for an hour and get back to it then
instead of waiting for the variable amount of time to pass by
watching it the whole time and start the next card download. Do you
see what was my predicament before my purchase of a universal 1300 ma
power supply? That power supply has solved my problem. Now one of my
2 other cameras is labled at 3 volts at 2 amps for a wall-wart
wall-mount power supply, but because these 2 cameras use usb to
transfer their card's memory contents it is fast enough for me to
monitor the transfer, etc.. The pocket camera uses the serial port
for transferring so that is why it is so slow. If these newer
operating systems were as plug and playable as windows 98 first
edition for example then this wouldn't even be a problem at all.
Solution - I will use my current wall mount universal power supply
with the pocket camera and use batteries (rechargeable) for the 2
other cameras. It is really frustrating to not be able to find decent
high powered power supply though - I doubt anyone has ever really run
into this problem I guess though. I can't even get the add/remove
hardware wizard to list any devices when I want to unplug/eject a
device too, and that's on 2 separate computers. I don't know what's
going on with that but what I do instead is do my "unplug/eject a
device"ing from the device manager which seems to do the job 100%.
Good luck all and thanks for keeping me from frying digital cameras,
later!

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