Hotrod headlamp

Nice :+1:
This one, sir, will burn :smiling_imp:

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

Wow. Nice work pp. Love the the idea using the grommet for the switch. Well done. :+1:

Project is not finished. I need to work on the battery box. So I haven’t worn it and don’t know if it will get branding iron hot or soldering iron hot.

Thanks guys :beer:

The heat sink seems to be 40x40x15mm. It is really a Hotrod. :smiley:

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?

With a heat sink like that, it’s possible heat may not be an issue at all? I can’t imagine a 20W soldering iron heating up that heat sink to the point where the fin end is uncomfortably hot.

Am I being unrealistic?

Very cool project. I like your water proof switch. Interesting to see your custom work with all that heatsinking still comes in lighter than the original doner light.

Yes.

FET driven triple will heat that thing up pretty good :wink:

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

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

Turbo test.

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.

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— :smiley:

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:

now you need to add a cooling fan

I couldn’t resist

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

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.

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.

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 :open_mouth:

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:

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?