Sinktube heatsink and Green P4, seems to get too hot...

[The Highwayman]

I'm going to use my sinktube heatsink for my next PVC saber project, but I need some help.

- 4 AAA NiMH 850 mah a piece
- a 1.2ohm 3 watt resistor
- green P4

The only problem is, that the heatsink gets exceptionally hot. Very hot. Stupid hot. The resistor also gets really hot.  The resistor changes power ot heat, so it should get pretty hot. is it too much current? Could i run this saber off one 3.7 Li battery?

What would be best?

Right now it reads at about 73 degree Fahrenheit. The resistor reads at 70 degrees Fahrenheit.

[darth_call]

Try using a 2.2 ohm 5 watt resistor.

[The Highwayman]

I don't have any, but next order from TCSS, I'll get some.

I just ordered some stuff last week an bought two 1 ohm, 2 watt resistors.

Odd... it seems to have gotten cooler... Hmmm... ??? ???

[LUMINARA UNDULI]

I think something else is wrong.  Check your connections again.  We direct drive at 4.5 V all the time with no resistor at all and they don't heat up.  4.8V shouldn't make that much difference.  

[The Highwayman]

I can direct drive it with 3 or four batteries? i am considering going to 3 AAA Nimh so I don't have to worry about resistors.

i'll look at my connections.

here is what i have

 + and - going to small solder pads on the P4. From there, the negative goes to where the switch would be attached, it's not in a hilt. Then the neg goes top the battery pack.

The + goes from led to resistor to battery pack. there is a QD on the positive and negative wires goign to the LED. I think my wiring is going to need to be redone. ::) :P :-[

EDIT: AHHH! I see now what it may be. The negative lead soldered on the LED is exposed enough to hit the Heatsink and cause a short. Could that be my issue?

[darth_call]

EDIT: AHHH! I see now what it may be. The negative lead soldered on the LED is exposed enough to hit the Heatsink and cause a short. Could that be my issue?

Uhm, yea, ...I would say, (unless u are attempting to make a food warmer of sorts), your leads should not touch the copper heat sink.

[The Highwayman]

EDIT: AHHH! I see now what it may be. The negative lead soldered on the LED is exposed enough to hit the Heatsink and cause a short. Could that be my issue?

Uhm, yea, ...I would say, (unless u are attempting to make a food warmer of sorts), your leads should not touch the copper heat sink.

Well ,i need a way ot keep my nachoes warm at football games i nthe winter... And a light-up food warmer could be a good idea. but not with a blinding green.

I'll redo my wiring to my LED btw. ;D :o ::) DOH!

Thanks for the Help guys and gals!

[LUMINARA UNDULI]

I can direct drive it with 3 or four batteries? i am considering going to 3 AAA Nimh so I don't have to worry about resistors.

i'll look at my connections.

here is what i have

 + and - going to small solder pads on the P4. From there, the negative goes to where the switch would be attached, it's not in a hilt. Then the neg goes top the battery pack.

The + goes from led to resistor to battery pack. there is a QD on the positive and negative wires goign to the LED. I think my wiring is going to need to be redone. ::) :P :-[

EDIT: AHHH! I see now what it may be. The negative lead soldered on the LED is exposed enough to hit the Heatsink and cause a short. Could that be my issue?

Caden, 3AAA NIMH is only 3.6V and since the green P4 has a minimum forward voltage of 3 and a max of 4 you'd be smack in the middle.  As long as you are properly heatsinked ;D you should have no problem direct driving and IMO rechargeables are always the best solution as it avoids you opening up the saber too much and also saves $$$ in the long run.  The resistor will reduce your brightness, and really isn't necessary.

[The Highwayman]

Sorry Allaerra, I just saw your post. I'm going to run the 4 AAA this time and shoot for 3 next time. ;) thanks for the help!

Oh, and since i've done some reading, i've figured out what some of this electrical stuff is! :D ;D