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Proto 2000 and White LED Headlights

Whether currently produced or not, both Fairchild and National currently show LM317 in a TO-92 package in their data sheets.

Here's the URL for the National datasheet:

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--- Joe

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Reply to
Joe
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A correction:

LM317L is the low power version of the LM317.

LM317L "guaranteed" outputs 100mA which makes it ideal for LED current regulation. I have used it to plug various types of LEDs (red, white, yellow, green...) into a breadboard with the LM317L wired for 15mA output current, without having to change components to adjust for the various forward voltages of the LEDs.

Another nice feature of using the LM317L in constant-current mode is that LEDs can be wired in series, as long as the input voltage is high enough.

--- Joe

Reply to
Joe

I should have replied this way first as I use this circuit all the time. Go to;

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I use a SMR between the two legs and it makes for a small package.

Reply to
Jon Miller

"Jon Miller" wrote in news: snipped-for-privacy@corp.supernews.com:

That's nice and small, looks like it'd be a good fit. Thanks.

Puckdropper

Reply to
Puckdropper

Joe spake thus:

So would you recommend using the LM317L (as a constant current source instead of as a voltage regulator) over the LM334?

Reply to
David Nebenzahl

Can't say that I would. I haven't used an LM334. Jon Miller apparently has, and quite successfully. The fact that a reverse connection to the input of the LM334 is well tolerated may actually convince me that the LM334 is a better choice.

--- Joe

Reply to
Joe

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