Can LM317 be used as GC PS regulator?

[goering]

Hi,

Could you guys help me out? Can the LM317T variable voltage regulator (up to +35v output at 1.5A) be used to regulate a power supply for a bridged LM3876 or LM3886 GC?

My neighborhood electronics store ran out of LM338 and I have a bunch of 317s. I think I heard somewhere that several chips can be configured to handle more current than a single chip can. How could this be done? Or could it be done at all?

I'd really appreciate the help. Thanks and regards.

[tool49]

You might want to try using transistors instead of multiple chips. Read the first, second and third parts of the following page:

http://ourworld.compuserve.com/homep...den/page12.htm

Hope this helps!
Sébastien

[goering]

sebastien, thanks so much for the info.

[carlmart]

Originally posted by goering
Hi,

Could you guys help me out? Can the LM317T variable voltage regulator (up to +35v output at 1.5A) be used to regulate a power supply for a bridged LM3876 or LM3886 GC?

My neighborhood electronics store ran out of LM338 and I have a bunch of 317s. I think I heard somewhere that several chips can be configured to handle more current than a single chip can. How could this be done? Or could it be done at all?

I wouldn't advise using the 317 as regulator for a GC at full power, perhaps only for a few watts.

For full power you need the regulator to handle at least 3A, like the LM338 or the LT1085.

Using pass transistors to increase the 317 current capacity will solve the problem, but one of the assets of the chip (low impedance) will suffer.


Carlos

[yopi3622]

I have used the LM317 at 15V with good results !!
Pros (compared to the unregulated version) :
- The soundstage is outstanding
- There seem to be more control in the bass region

Cons :
- There seem to be a little coloration in the sound

You can go up to moderate volumes (enough to wake my neighboorhood up
IMHO these 1 or 2 amp regulators can be used for active speaker projects.
I am planning to try the LM2940 which delivers 1 or 2 amps too ; he seem to have better mesurement...
Has anymone tested it ???

As anyone did tests with low power regulators ???

Yopi

[carlmart]

Originally posted by yopi3622
I have used the LM317 at 15V with good results !!

We are talking current capacity here, not voltage. The 317 can handle up to 1A.

Others regulators might be tried, but it's better not to use them at higher volumes, except if they are 3A types.


Carlos