How do I Configure a Adjustable Voltage Regulator?

Hello! Im working on a project that uses a 9v battery to power a circuit. I would also like to power a circuit with the same battery.
But this circuit was designed to run off 2 AAA. I've gone searching and It seems like I was only needing a Voltage regulator to step down that 9v to 3v ish. 
Problem is that I couldnt find a output 3v one! So I had to buy an adjustable one from Fry's Electronics. And I don't know how to configure this!
haha, this is quite a problem. And documentation on this product is horrible. Can anyone please help me out??

Product is NTE1900 3 terminal positive adjustable voltage regulator. Input is 9v, I want an output of 3v. How would I set this up?


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3rd time !

The datasheets ROTTEN. Lets treat it as a classic 317 and see what happens.

Conenct a 220 Ohm resistor from Vout to ADJ. Connect a 330 Ohm from Adj to ground.

Connect 9V to Vin. And test with a meter !!

Good answer -- and it came thru! I hate when the site bugs out!
framistan6 years ago
Just a side note for those wishing to use a TO-220 style LM317. Be sure to attach the regulator to a heatsink. Be sure to use the insulator kit so the metal tab of the LM317 does NOT touch ground, or it will not work and will overheat. Check conductivity from ground to tab should be NOT connected electrically (only thermally).
noobiefied (author) 6 years ago
Huh 3rd time what?
Yeah i visited National's write up on the 317 and I am so confused on how it is supposed to work.

So if im reading this right... (kind of confused on how this thread is being worded haha) you have tested it with 220 and 330 and gotten out 3v?

On yahoo answers it seems like some one worked out what resistors to use which they said was to be 240 -R1 and 390 -R2. I tried that setup and it didnt work well... nothing happened.

and how am i supposed to view this thing? words up? or curve up?
I tried to answer your queston this morning, and the system lost my reply twice.....

240-390 or 220-330 should work fine.

The correct orientation ? Dunno. This is a very poor data sheet. Try curve up. And if all else fails buy an LM317 !

noobiefied (author)  steveastrouk6 years ago
Thank goodness you still posted!
Thanks a bunch. :D
TEst answer.....I've tried three times now.