First real mod! Dorcy Metal Gear, plus SSC P4 am I missing anything?

[Brian10962001]

Ok guys, I am on a mission to do my first real mod! This forum is awesome btw. My planned mod is a Dorcy Metal Gear 3 AAA that runs a Luxeon 1 watt. I have a pair of these lights and they were my first ever LED lights. I remember buying them and thinking "this is the future, all lights will be led soon", it rocks being right .

Anyways my plan is to install these: http://www.dealextreme.com/details.dx/sku.1445
I have already ordered 3 of them in case I mess one up. I know the Dorcy Metal Gears are direct drive and I was planning to leave them that way. I did a little research and I think this will be ok. I'm a bit nervous to get into the control chips because I don't quite fully understand them (know they limit current and ramp up output, can use PWM to pulse the light, can enable modes etc). Any input would be greatly appreciated, and I'll try to keep everyone informed on how it works out for me. Thanks in advance everyone!

 

[jpapazit]

thanks for the idea. according to the posts in the sku it looks like itll work as a replacement for luxeon which is in my dorcy. should be pretty straight forward. ill order one with my next dx order.

 

[dirtech]

If you can fit a driver in that host somehow it won't be that hard to figure out by searching here. Otherwise direct drive should work.

 

[Brian10962001]

I can fit a driver no problem, there's quite a bit of room in the host. The problem is I'm not sure what I'm looking at as far as drivers go. I know I would need a buck driver to reduce the current (4.5v battery pack, 3.7v rated LED) but I don't really want modes, nor do I know enough to venture there now. I pulled the Dorcy's apart tonight and they have a red, black, gold, gold resistor in them which is rated at somewhere around 2 ohm.

I'm still not really clear on how the resistance value in ohms translates into the ma draw from the batteries. I have never messed with that math before. I'm assuming if i swap the 2 ohm resistor with a 1 ohm, or slave another 2 ohm across it I will double my ma's to the LED. I've heard of people doing that but I'm not sure of the limits, time for more homework :devil:

 

[aEx155]

An easy way to choose the best resistor value is just to measure the current going through the LED, assuming you have a multimeter.

 

[ChibiM]

Hi Brian,
thanks for posting at my thread....

but will you use some thermal...stuff... to transport the heat?
like I was talking about in my thread.
or you think you dont need it?

 

[Brian10962001]

I actually purchased the LED's already installed on the stars, so I won't have to worry about the thermal paste behind them. However I've dealt with thermal paste a few times before, and my recommendation would be to use either thermal epoxy, or the thermal paste, not thermal grease. I've heard that the SSC P4's have the positive anode exposed on the back instead of the negative so it's important to keep it from making a connection to your star/heat sink. That's just something I would keep in mind if you use that LED.

 

[ChibiM]

Brian... good point.
Im now really doubting of getting the same star.
I think my luxeon has the - on the bottom..
hmmmm:thinking:
I need to come up with a solution.. before I order