Maker Pro
Maker Pro

[Newbie] Supplying power to a project

I one of those folks who knows enough to be dangerous. I have a good
grasp of a lot of basics, but I'm missing a fundamental piece that's
really important for a project I'm doing.

I've built a nice little FM transmitter kit which I'm putting in a nice
wooden case which will have an iPod dock on it. The transmitter works
great. It runs best on 12V.

The iPod will charge at 12V. This, of course, could be a really nice
way to both be broadcasting and charging at the same time. That's my
intention.

I see the iPod will take 12V on the firewire power connectors, and it
says "1A Max".
The basic piece of information I'm missing is: I want to supply ample
power to the iPod and transmitter. Do I need to worry about supplying
too many amps? Is amps just a measure of what the device will draw
and/or use? And how can I know how many amps the transmitter is using?

And I ask all this fearfully, knowing that I may not even be asking the
question correctly.

Can anyone help me understand this, or point me to someplace I can
figure this out?

Thanks much!

P.S. I already have some nice links to simple voltage regulators to
help know I'm getting the right voltage there.
 
R

Rene Tschaggelar

Jan 1, 1970
0
I one of those folks who knows enough to be dangerous. I have a good
grasp of a lot of basics, but I'm missing a fundamental piece that's
really important for a project I'm doing.

I've built a nice little FM transmitter kit which I'm putting in a nice
wooden case which will have an iPod dock on it. The transmitter works
great. It runs best on 12V.

The iPod will charge at 12V. This, of course, could be a really nice
way to both be broadcasting and charging at the same time. That's my
intention.

I see the iPod will take 12V on the firewire power connectors, and it
says "1A Max".
The basic piece of information I'm missing is: I want to supply ample
power to the iPod and transmitter. Do I need to worry about supplying
too many amps? Is amps just a measure of what the device will draw
and/or use? And how can I know how many amps the transmitter is using?

And I ask all this fearfully, knowing that I may not even be asking the
question correctly.

Can anyone help me understand this, or point me to someplace I can
figure this out?

Thanks much!

P.S. I already have some nice links to simple voltage regulators to
help know I'm getting the right voltage there.

It is not the amps you have to worry but the
switcher noise. The cheap transmitters are sensitive
to the supply, especially when a switcher is used.
You are never able to filter the noise introduced
by the switcher, meaning the switcher noise is
going to be broadcast.

Rene
 
G

Genome

Jan 1, 1970
0
I one of those folks who knows enough to be dangerous. I have a good
grasp of a lot of basics, but I'm missing a fundamental piece that's
really important for a project I'm doing.

I've built a nice little FM transmitter kit which I'm putting in a nice
wooden case which will have an iPod dock on it. The transmitter works
great. It runs best on 12V.

The iPod will charge at 12V. This, of course, could be a really nice
way to both be broadcasting and charging at the same time. That's my
intention.

I see the iPod will take 12V on the firewire power connectors, and it
says "1A Max".
The basic piece of information I'm missing is: I want to supply ample
power to the iPod and transmitter. Do I need to worry about supplying
too many amps? Is amps just a measure of what the device will draw
and/or use? And how can I know how many amps the transmitter is using?

And I ask all this fearfully, knowing that I may not even be asking the
question correctly.

Can anyone help me understand this, or point me to someplace I can
figure this out?

Thanks much!

P.S. I already have some nice links to simple voltage regulators to
help know I'm getting the right voltage there.

Hi.

I am not the moderator of the misc.business.product-dev group but that
sounds like the sort of idea the group would be interested in.

Try

http://groups.google.com/group/misc.business.product-dev?lnk=gschg&hl=en

DNA
 
F

Frithiof Andreas Jensen

Jan 1, 1970
0
I see the iPod will take 12V on the firewire power connectors, and it
says "1A Max".

That would be the *maximum* current drawn - probably when
fast-charging the battery(?).
The basic piece of information I'm missing is: I want to supply ample
power to the iPod and transmitter. Do I need to worry about supplying
too many amps?

Yes - overkill is not better, it is just waste!

You can buy/design a 12V, 1A linear supply without too much trouble.
At 3A .bob..bob.. maybe a switcher is necessary and then you will have
real trouble filtering the noise out (after having real trouble with
the design and layout).

What you *do* need to worry about is overvoltage - it is sad to fry an
ipod due to some power supply bug! A quick fix could be to use a
Transorb on the output of the supply so if it does blow up, the
tranzorb will short the supply, cause the fuse to blow and save the
Ipod.

Is amps just a measure of what the device will draw
and/or use? And how can I know how many amps the transmitter is
using?

Measure it - one would expect that the transmitter be less than 50 mA;
unless you want the visit from the "proper authorities". ;-)
 
J

James Waldby

Jan 1, 1970
0
Genome wrote:
....
I am not the moderator of the misc.business.product-dev group but that
sounds like the sort of idea the group would be interested in. ....
DNA

Perhaps you've misread (or misheard) the misc.business.product-dev
group. I'd really be surprised if they are interested in having you
be the moderator. Of course, you could be right - go for it! Could
only be an improvement.

-jiw
 
Top