Mahoosive Resistors

[mikeclem]

Seasons greetings,

So, I need a 3.8W and 3.3W resistor for my build. The ceramic wire wound 5W's are (as the title suggests) physically mohoosive and a real challenge to fit in a hilt. Suggestions on a postcard please as to a solution/alternative.

Rgds.

[Nebula]

The difficulty in dissipating large amounts of heat with resistors is that they must be large enough or else they will burn up. The easiest solution would be to use a lower voltage battery solution so the resistors wouldn't have to dissipate as much heat and therefore would be smaller.

[mikeclem]

The difficulty in dissipating large amounts of heat with resistors is that they must be large enough or else they will burn up. The easiest solution would be to use a lower voltage battery solution so the resistors wouldn't have to dissipate as much heat and therefore would be smaller.

Aye, true dat (he says mixing ethnic patois). While I appreciate you cannae change the laws of physics Cap'n (he says mixing franchises) I was hoping there may be a smaller product that might do the job or you may say: 'oh, use a 3W metal film - it'll be fine'.

Mike

[darth_chasm]

We don't know what your set up is, so lowering your battery solution may not be an option. While I try to always use TCSS as my source for saber goods, sometimes what is needed is not available. Without providing direct info, I will say there are a plethora of electronics resources a Google search away.

Another option is to be more "creative" with your cram-fu

[mikeclem]

We don't know what your set up is, so lowering your battery solution may not be an option. While I try to always use TCSS as my source for saber goods, sometimes what is needed is not available. Without providing direct info, I will say there are a plethora of electronics resources a Google search away.

Thanks Chasm - being in the UK, TCSS is often aspirational and certainly not justifiable for teeny tiny items like resistors. My post was borne of not being able to find a 5W alternative that didn't have a large footprint. A buck is potentially another option but yet more wire to cram.

I'm running a Tri-Cree via a PC3.5 so reducing it to a single 3.7 cell is certainly feasible (actually 2X 14500 in parallel) and would extend the run time.

[Greenie]

Dude, if you're in the UK, go to Maplins. I did that just yesterday and bought various individual resistors for some basic colour mixing.
You can look online for what they have.

[Darth Nater]

I just did a Tri-Cree heatsink holder swapout on a PC2.0 (7.4V as well) which was originally using a 4 die LedEngin. Before I was able to get away with the small resistor on the PEX for those 2 dies wired in series. The module I got was a Tri-Cree which of course needed one of those fat ace 5W resistors for the FOC single die. I didn't think I was going to be able to pull it off originally since that heatsink sits in the neck of a ribbed choke section, but then I realized I had the old V3 Heatsink which goes down in there and takes a lot of space. I was able to order the V4 flat heatsink and keep that fat resistor up close to it, and attached to my heatsink wiring (on the heatsink side of the JST connector) and had the space. The 18degree lens for the Tri-cree is short in comparison with the single die lenses and it sits higher up inside the holder. The flat heatsink already saves like a half inch of space, plus it will screw up in there higher as well. This saved me the needed space in that tight neck section to be able to pull off the fat 5W resistor on a JST along with the main 2 LED dies on another JST. Basically, I was saved by the flat version V4 heatsink.

May not work in your case, but I figured it worth mentioning.

[mikeclem]

Dude, if you're in the UK, go to Maplins. I did that just yesterday and bought various individual resistors for some basic colour mixing.
You can look online for what they have.

Oh, I'm intimately familiar and frustrated with what Craplins have to offer. Their 7W wire wound resistors are comically large. The 10W's that they carry could be used as a house brick.

I suspect a transistor may be a potential solution (some form of FET), but I'm coming round to the idea of a 3.7v solution.

[Greenie]

Ok. I must admit you're right there,but as I actually got what I went for this time, I was being optimistic . I've used quite a few metal film resistors of a low wattage and never really had any heat issues.

[mikeclem]

Ok. I must admit you're right there,but as I actually got what I went for this time, I was being optimistic . I've used quite a few metal film resistors of a low wattage and never really had any heat issues.

Yes, I've chanced my arm the same way in the past without a problem. However, I'm not going to take the risk with a costly petite crouton (imported from TCSS with eye watering import duty and shipping). Ah, to be in the land of the free and wide ranging hobby supplies....