Hotrod headlamp

finges · 2018-08-17T09:53:00.000Z

Zulumoose:

Am I being unrealistic?

Yes.

FET driven triple will heat that thing up pretty good

kiriba-ru · 2018-08-17T10:13:36.000Z

Zulumoose:

Am I right in saying that if it pulls 40W as per the measurements shown, about half of that is light output, so there is only 20W of heat to deal with?

No.
Light output is more like 10 to 15%.

Nooner · 2018-08-17T11:34:23.000Z

That’s really cool Pinkpanda. I like it! Thanks for posting the build.

freeme · 2018-08-17T11:43:46.000Z

Turbo test.

pinkpanda3310 · 2018-08-17T15:25:03.000Z

Hahaha that’s funny freeme :laughing:

I did get to wonder if maybe I’ll end up like Michael Jackson and burn my hair off. Hence I made this video of the thermal step down. I’m wondering how much of a difference it makes having the driver side by side to the mcpcb and in the same cavity. Of course 10+ amps was always going to be too much for a headlamp anyways. Maybe a fan should’ve been on the menu.

chops728 · 2018-08-17T16:11:36.000Z

Looks like you could end up with an imprint of that heat sink on your forehead— WARNING—stay away from hair products when in use—

MRsDNF · 2018-08-17T20:45:53.000Z

It would be interesting to see the same test with a slight breeze running across the heat sink.
21 degrees ambient. Its about half that here. :person_facepalming:

Lexel · 2018-08-17T21:17:40.000Z

now you need to add a cooling fan

chops728 · 2018-08-17T21:34:56.000Z

I couldn’t resist

pinkpanda3310 · 2018-08-18T00:12:09.000Z

chops728:

Looks like you could end up with an imprint of that heat sink on your forehead— WARNING—stay away from hair products when in use—

Oh I bet that’s what ruined Michaels hair do…… :laughing:

MRsDNF:

It would be interesting to see the same test with a slight breeze running across the heat sink.
21 degrees ambient. Its about half that here. :person_facepalming:

I did think about the airflow or lack thereof but figured the initial heat being generated would not be swayed much. Turbo charged heating….

Also my garage is kinda cosy. It was a sunny (but not too warm) day yesterday and the heat emitted from 2 car engines makes it warmer in the garage than in the house.

SKV89 · 2018-08-18T00:59:38.000Z

freeme:

Turbo test.

Wow that just gave me an idea. Imagine someone created an Oslon 500kcd headlamp with a remote control. You can turn it on anytime at will and will scare the shit out of people.

pinkpanda3310 · 2018-08-19T12:21:33.000Z

I didn’t get to finish this project this weekend :weary: But it’s getting close.

The battery box and cable was a big source of resistance. Do you like the ‘change led’ indicator? :laughing: :laughing: :person_facepalming:

Low fat diet…. errm … I mean low resistance …

I still need to add a plug to the box for the power cable. I want to be able to unplug the batteries when not in use. So I added an led to the cable plug to indicate power and remind me/user to unplug it when finished. I stole the led and resistor from the original pcb but screwed up the led with my awesome soldering technique :person_facepalming: So I had to steal an led from an old fried bikelight driver. It took a while but I managed to get it working.

I ran out of 5 minute epoxy so I used regular epoxy but soon after applying it I realised I should have used hot glue…. it took aaages to set and I kept turning it now and then but ended up falling asleep before it had fully set and it nearly stuck to my bedside lamp

So after feeling tickityboo about my awesome soldering skills and wise choice in glues I’ve come to the realisation that the cable is much longer than anticipated. I know I should have checked it but I was figuring a little leeway for the headband to stretch will be good. It turns out that little leeway isn’t little at all, I should have checked :person_facepalming: Now I need to redo the end :weary:

pinkpanda3310 · 2018-08-19T12:10:11.000Z

Oh I nearly forgot I did some more testing. Using the ramping I adjusted the current.

I tried to set the current to 1 amp and landed on 0.94a
ambient temp 19C
5 min 30C
10 min 36C
11 min I picked it up for a bit and temp dropped to 35C
15 min 37.5C
At this point I stopped. I figured it will not hit thermal step down with this current on the bench

Second test I got lucky and landed on 1.50a
ambient temp 21C
1 min 27C
2 min 30C
3 min 34C
4 min 36C
4:45 thermal step down to 0.8a 38C
5 min 38C
6 min 38C

I thought it odd to step down when the temp externally wasn’t that high. It makes me wonder (again) if the driver and leds immediately next to each other and in the same cavity is having an effect on thermal properties?

Lexel · 2018-08-19T14:55:09.000Z

pinkpanda3310:

Oh I nearly forgot I did some more testing. Using the ramping I adjusted the current.

I tried to set the current to 1 amp and landed on 0.94a
ambient temp 19C
5 min 30C
10 min 36C
11 min I picked it up for a bit and temp dropped to 35C
15 min 37.5C
At this point I stopped. I figured it will not hit thermal step down with this current on the bench

Second test I got lucky and landed on 1.50a
ambient temp 21C
1 min 27C
2 min 30C
3 min 34C
4 min 36C
4:45 thermal step down to 0.8a 38C
5 min 38C
6 min 38C

I thought it odd to step down when the temp externally wasn’t that high. It makes me wonder (again) if the driver and leds immediately next to each other and in the same cavity is having an effect on thermal properties?

this is why you can store another temp value over the Narsil settings User interface

MRsDNF · 2018-08-19T20:26:41.000Z

:+1:

pinkpanda3310 · 2018-08-20T01:59:30.000Z

Lexel:

this is why you can store another temp value over the Narsil settings User interface

But I don’t understand how the internal step down temp (55C) can be the same for both the scenarios above -
max output external temp 56C at step down
low output external temp 38C at step down

It doesn’t make sense to me :question:

I’m guessing the temp sensor is facing up on the driver and therefore measuring air temp within the cavity. Had I turned the driver upside down then the temp sensor would be closer the heatsink and have a different reaction time to the above cases :?: maybe

pinkpanda3310 · 2018-08-23T01:05:31.000Z

This light is pretty much done now. Though I’m thinking of changing the optic as it really is floody. Generally I prefer flood for headlights and edc’s but I get the feeling something less floody would seem even more extreme for a headlight like this.

I cut the cable shorter and redid the lighted plug.

It’s not very easy taking a pic of ones own back’o’the head

Finished wiring the battery box

Battery box under load

…aand the all important beamshot. A quick one with my phone (There might be 2 of the same pic showing)

Just for comparison this is my favourite headlamp, a skilhunt H03

Thanks for looking :sunglasses:

MRsDNF · 2018-08-22T20:24:11.000Z

Its good to see you finish the build pp. Well done. Maybe a change of optic and led to tighten up the beam pattern.

Firelight2 · 2018-08-22T22:30:38.000Z

duramax:

such a cool project, many thanks for sharing. How hot does it get when wearing?

I was thinking the same thing.

So if you have it running at full power for awhile and then accidentally bump it so the heatsink tilts back will your forehead look like you just roasted it in a waffle iron?

pinkpanda3310 · 2018-08-23T01:15:37.000Z

MRsDNF:

Its good to see you finish the build pp. Well done. Maybe a change of optic and led to tighten up the beam pattern.

I don’t think I’ll change the leds since I glued the star to the heatsink. The optic should be quick and easy though :innocent:

Firelight2:

duramax:

such a cool project, many thanks for sharing. How hot does it get when wearing?

I was thinking the same thing.

So if you have it running at full power for awhile and then accidentally bump it so the heatsink tilts back will your forehead look like you just roasted it in a waffle iron?

I’ve only worn it briefly for testing and the pic. I don’t expect any hot iron branding with the rubber mount acting as an insulator. The rubber mount grips it reasonably firm so I doubt it will slip even in the wet.