5W with broken leads

HELP Please! I went to mod my first 5W. I popped the emitter off of the star OK, but when I tried to trim the leads it fell off. Same thing happened to other lead. I was able to dremel and solder on wire-wrap wire, but, now I don't know which is which. Any way to power it up safely and figure it out? (with the 50-50 chance of powering it up in reverse?) Can I fire it up with no heatsink for a second or two? Thanks!

sflate,

On a 5W, the + lead has a small rectangular hole punched in it. Can you still see it? You should be OK with 6V or so for a quick test- very short term reverse pol. shouldn't shouldn't hurt it. (I've done it.)

Larry

On the 2 5 Watt stars ive had, there were holes in BOTH tabs. To get round this, i desoldered the negative tab, and just cut the positive tab at the first bend. This makes identification easier once the emitter is off the board, Just be sure to remember which lead is shorter...(doh)
2 CR123's direct drive should be fine, this is what i use to test 5 watters to make sure they work.

Reverse polarity isn't a big deal if it does not exceed too much (ie, not in the situation of a boost converter, in which reverse polarity will result in over 10x the designed voltage). But you should have some resistor to limit the current. You won't want to try powering up at the full 5w without proper heat-sinking even for a short period of time.

[ QUOTE ]
kakster said:
On the 2 5 Watt stars ive had, there were holes in BOTH tabs. To get round this, i desoldered the negative tab, and just cut the positive tab at the first bend. This makes identification easier once the emitter is off the board, Just be sure to remember which lead is shorter...(doh)
2 CR123's direct drive should be fine, this is what i use to test 5 watters to make sure they work.

[/ QUOTE ]

kakster,

You're right! I just dug out the 4 I have. The tab adjacient to the + lead is longer on all 4, which might be a help.

Larry
(Crummy eyesight got me again.)

Thanks for all of the 'quick' info. I'll try to heatsink the best I can for my brief second or two test. I have a couple of 5W that have been sitting around waiting for a home. I've never tried a 5W yet so I grabbed the worst binned of the bunch. I've swapped about 4-5 1W'ers and haven't had a problem yet. We'll see how this one goes. Thanks again everyone.

Did you forget to un-solder the leads off of the star before bending it?!

Nope! I actually got it off the star OK but messed it up trying to trim the leads. I've done it several times on the 1W with no problem so either the 5W leads break easier or I just plain #$%!@'d up! I'm sure it didn't help that I just got home from work (Ford Engine & Castings Plants in Cleveland) after a full day of trying to get our Systems back online after the power outage. I'm sure I was a bit cross-eyed at the time. FYI, my homemade MM+ R2H performed great through the crisis running for over 4 hours straight. (1 battery change after 2+ hours) That's what inspired me to try to make something of the 5W laying around. A bit more light would have been great at some points.

If you broke the lead off flush with the side of the body (the black plastic part that goes around the slug), you can safely grind away some of the plastic - enough to solder on to.

I use a dremel with a hi-speed cutting wheel. Work carefully so you don't go into the body too far.