Autonomous headlamp design enquiry· Page 4

Mine exploration, photographs and mining history for mine explorers, industrial archaeologists, researchers and historians

a b c d e f g h i j k l m n o p q r s t u v w x y z

Peter Burgess
50.2% (Neutral)
Newbie

11 years ago

#61

If you improve the lamp efficiency too much, people will forget how to charge up the batteries.

royfellows
50.2% (Neutral)
Newbie

11 years ago

#62

"Peter Burgess" wrote:
If you improve the lamp efficiency too much, people will forget how to charge up the batteries.

Go away
:lol:

My avatar is a poor likeness.

NewStuff
50.2% (Neutral)
Newbie

11 years ago

#63

Mine has an override on it.

The hardest bit is not the variable power feedback (done, easy), but putting the power (20amps-ish) into the head and dissipating it. I'm still trying to blag time on the 5axis at work.

Searching for the ever elusive Underground Titty Bar.

DDDWH CC

gNick
50.2% (Neutral)
Newbie

11 years ago

#64

"NewStuff" wrote:
The hardest bit is not the variable power feedback (done, easy), but putting the power (20amps-ish) into the head and dissipating it. I'm still trying to blag time on the 5axis at work.

Something worth bearing in mind when designing your heatsink, fins can be remarkably innefective without a strong air flow. The deeper and closer the fins get the less effective they are. I spent a lot of time trying to get a passive heatsink to work (on an inverter drive) and it was interesting that on a 50mm long fin on about 20mm pitch, only the outer 10mm or so actually showed head loss. Basically the air closer to the root tends to stay put unless pushed.
So you can do some lovely machining to create fins but all you acheive is a weight saving mud trap!

Don't look so embarrassed, it's a family trait...

tangent_tracker
50.2% (Neutral)
Newbie

11 years ago

#65

Absolutely agree Nick, fins are a mud trap and become next to useless when muddy. The answer is probably to pick the correct LED (as I have found out the XML is not necessarily the best choice despite its claim for efficiency!), optics and an efficient driver.

I will not argue with you Roy regarding feedback. The very fact it increases efficiency and hence battery life is IMO a justifiable reason to employ the system, especially in squalid caves, as long, as has been stated you are able to override and work off manual modes, as appears can be done with both my own and Newstuff's own lamp.
This is making me more determined to get my lamp out there a bit more for other's to try, needs a lot of work to take it beyond a prototype though!

NewStuff
50.2% (Neutral)
Newbie

11 years ago

#66

I do realise the differences in fin design for passive and active airflow. Mine will be well spaced out. Mud is not an issue, I have no intention of selling my lamps, and will not end up in a muddy cave very often, slate mines being my thing.

I do think that a heatpipe is the way to go (for me at least), and integrate the heatsink into the battery box design. It should have far less chance of getting all caked up at the back of the head.

Searching for the ever elusive Underground Titty Bar.

DDDWH CC