Switching regulators for 12V batt. to 12 regulated?

[Will Rouesnel]

I'm presently in the process of constructing a robot as a hobby project, and
I want to use switching regulators in order to maximize battery life and
stabilize some voltages for things (I have a CCD camera I want to put on it
that uses +12V). I'm aware of the LM2577 series of regulators and the
accompanying +5V model as well. Obviously the 5V is a step down regulator
and with 12V batteries poses no problems, but I want to get a stable 12V as
well from the batteries (which could range anywhere from about 15 to 11V [I
know these are extremes of charge]).
Does anyone know how the LM2577's perform if the input voltage is higher
then the output? Do they regulate it down to 12V or what happens here?

- Will Rouesnel

 

[John Crighton]

On Tue, 01 Feb 2005 04:24:50 GMT, "Will Rouesnel"
<electricitylikesme@hotmail.com> wrote:

I'm presently in the process of constructing a robot as a hobby project, and
I want to use switching regulators in order to maximize battery life and
stabilize some voltages for things (I have a CCD camera I want to put on it
that uses +12V). I'm aware of the LM2577 series of regulators and the
accompanying +5V model as well. Obviously the 5V is a step down regulator
and with 12V batteries poses no problems, but I want to get a stable 12V as
well from the batteries (which could range anywhere from about 15 to 11V [I
know these are extremes of charge]).
Does anyone know how the LM2577's perform if the input voltage is higher
then the output? Do they regulate it down to 12V or what happens here?

- Will Rouesnel

Have a look here,
http://repairfaq.ece.drexel.edu/sam/b12vc.gif
might be worth having a little play with it.
Regards,
John Crighton

 

[Will Rouesnel]

"John Crighton" <john_c@tpg.com.au> wrote in message
news:41ff1d44.1927732@News.individual.net...

On Tue, 01 Feb 2005 04:24:50 GMT, "Will Rouesnel"
electricitylikesme@hotmail.com> wrote:


I'm presently in the process of constructing a robot as a hobby project,
and
I want to use switching regulators in order to maximize battery life and
stabilize some voltages for things (I have a CCD camera I want to put on
it
that uses +12V). I'm aware of the LM2577 series of regulators and the
accompanying +5V model as well. Obviously the 5V is a step down regulator
and with 12V batteries poses no problems, but I want to get a stable 12V
as
well from the batteries (which could range anywhere from about 15 to 11V
[I
know these are extremes of charge]).
Does anyone know how the LM2577's perform if the input voltage is higher
then the output? Do they regulate it down to 12V or what happens here?

- Will Rouesnel



Have a look here,
http://repairfaq.ece.drexel.edu/sam/b12vc.gif
might be worth having a little play with it.
Regards,
John Crighton

Thanks for the link but I would like to know how the IC's deal with this
situation since they're somewhat easier to use (esp. if the big package
includes the inductors).

- Will Rouesnel

 

The problem with this circuit is that it still uses a linear
regulator...