Simple power supply

G

General Specific

Guest
I have a circuit that needs 5v DC. I put in a simple voltage divider to
take the 9v from a battery down to the required 5v. The obvious problem is
that this only works while the battery is at or close to full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as the
battery degrades (obviously until the battery drains past 5v).
 
General Specific <bill@msn.com> wrote in
news:Xns94EF70928D013aaa@207.106.93.226:

I have a circuit that needs 5v DC. I put in a simple voltage divider
to take the 9v from a battery down to the required 5v. The obvious
problem is that this only works while the battery is at or close to
full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as
the battery degrades (obviously until the battery drains past 5v).
Click to expand...
A (low drop) regulator or a resistor-zener combination.


--
Regards,
Soeren

* If it puzzles you dear... Reverse engineer *
 
Soeren <Look@iNO-SPAMt.dk> wrote in news:Xns94F189D70EAA7oo8ooLooK4iToo8oo@
62.243.74.163:

General Specific <bill@msn.com> wrote in
news:Xns94EF70928D013aaa@207.106.93.226:

I have a circuit that needs 5v DC. I put in a simple voltage divider
to take the 9v from a battery down to the required 5v. The obvious
problem is that this only works while the battery is at or close to
full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as
the battery degrades (obviously until the battery drains past 5v).

A (low drop) regulator or a resistor-zener combination.
Click to expand...

Great. Can you point me to a reference or a schematic?
 
In article <Xns94F363CE06E60aaa@207.106.93.226>,
General Specific <bill@msn.com> wrote:

Soeren <Look@iNO-SPAMt.dk> wrote in news:Xns94F189D70EAA7oo8ooLooK4iToo8oo@
62.243.74.163:

General Specific <bill@msn.com> wrote in
news:Xns94EF70928D013aaa@207.106.93.226:

I have a circuit that needs 5v DC. I put in a simple voltage divider
to take the 9v from a battery down to the required 5v. The obvious
problem is that this only works while the battery is at or close to
full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as
the battery degrades (obviously until the battery drains past 5v).

A (low drop) regulator or a resistor-zener combination.




Great. Can you point me to a reference or a schematic?
Click to expand...

________
9V >-------| 78L05 |------------> 5V
| | | |
| ---------- |
| | |
| | |
----- | ----- .1 uF
10uF ----- | -----
| | |
---------|-----------
|
|
Gnd

The 78L05 is a 3 terminal voltage regulator that will be good for 100mA.

Al

--
There's never enough time to do it right the first time.......
 
General Specific <bill@msn.com> wrote in
news:Xns94F363CE06E60aaa@207.106.93.226:

A (low drop) regulator or a resistor-zener combination.

Great. Can you point me to a reference or a schematic?
Click to expand...
What magnitude of current are we talking about ?


--
Regards,
Soeren

* If it puzzles you dear... Reverse engineer *
New forum: <URL:http://www.ElektronikTeknolog.dk/cgi-bin/SPEED/>
 
On Thu, 20 May 2004 15:03:53 +0000, General Specific wrote:

I have a circuit that needs 5v DC. I put in a simple voltage divider to
take the 9v from a battery down to the required 5v. The obvious problem is
that this only works while the battery is at or close to full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as the
battery degrades (obviously until the battery drains past 5v).
Click to expand...
I don't know how much the output voltage you got when the
battery is not fulfully charged. If it is more than 5V, then, try using
either a 5V voltage regulator or a zenor diode which has approximately 5V
zenor breakdown voltage. If it is not, then, try using a rectfying circuit
followed by the regulator circuit I mentioned. Or, you may just go to some
electronic store to buy a ac to dc adopter with build-in voltage
regulator. It should not cost you more than buidling one yourself.
 
Use a (3-PIN) low drop voltage regulator
"Amos Ku" <amos_ku@comcast.net> schreef in bericht
news:pan.2004.06.04.08.25.14.35027@comcast.net...
On Thu, 20 May 2004 15:03:53 +0000, General Specific wrote:

I have a circuit that needs 5v DC. I put in a simple voltage divider to
take the 9v from a battery down to the required 5v. The obvious problem
is
that this only works while the battery is at or close to full charge.

I'm looking to learn how to provide 5v to the circuit consistantly as
the
battery degrades (obviously until the battery drains past 5v).

I don't know how much the output voltage you got when the
battery is not fulfully charged. If it is more than 5V, then, try using
either a 5V voltage regulator or a zenor diode which has approximately 5V
zenor breakdown voltage. If it is not, then, try using a rectfying circuit
followed by the regulator circuit I mentioned. Or, you may just go to some
electronic store to buy a ac to dc adopter with build-in voltage
regulator. It should not cost you more than buidling one yourself.
Click to expand...
 
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