Hello!
I'm all new to the whole DIY LED, electronics, flashlight thing, but have found me an intersting project that I simply need some input on to get started. I'm an mechatronical engineer, so I know some basic stuff about electronics, and can hopefully follow your techy discussions.
So here's the ting. I'm an enduro driver, and at this time of the year it gets quite dark here in Norway (and snowy and cold, but thats a different discussuion). In a moment of weekness, or strength, depending on how you see it, I found it to be a cool idea and cheap project to try to put a 50 LED chip inside my enduro headlight instead of the 35W halogen buld thats barely glowing. I ended up buying the following components:
50W led and driver
http://www.ebay.com/itm/261727353516
AC-DC converter
http://vod.ebay.com/vod/FetchOrderD...82603&transid=1217008707014&viewpaymentstatus=
Headlight mask
http://www.ebay.com/itm/12V-35W-BLA...ash=item3aa521df88:g:bJ0AAOSw1vlUx25n&vxp=mtr
The plan is to place the led so that is shines through the whole where the bulb normally sits. It fits quite perfect actually. (This is only for off-road use). My bike has a battery and strater motor, and hence a DC circuit. I'm however not 100% sure of the stator output, but I think it is 55W, so in order to ensure that I do not drain the battery, I will connect the AC-DC converter to my current lighting circuit which is 12V AC. (at least then I think I don't steal from the battery, only in worst case take all the juice needed to charge it?)
Now that it's all here, and I've done some more reading i realize i have a couple of questions I can't really figure out.
Firstly, and most importantly there is the temperature issue. This has to be a fairly rugged design, and I don't want to use active cooling. I also don't have that much space, So I don't want the passive cooler to be any bigger than necessary. The headlight will mostly be used during fall/winter in relatively cold ambient temperatures (+10 - -20°C), and there will probably be a certain amount of airflow, though nothing like highwayspeed or a dedicated fan. So what I can't figure out is how hight temp I can allow the LED to get before it gives in, and where I should try to measure this temp. I intend to make a test setup with the heatsink I have, and see how it goes and measure the temp.
I also though of installing a thermoswitch embedded between the led and the sink (or on the sink only?), but don't know for what temp i need the switch to be. This would be only to shut it off in order not to fry. Something like this maybe?
http://www.ebay.com/itm/2-Pcs-Tempe...560825?hash=item35e4a933f9:g:uaQAAOSw-vlVlhGJ
So.... Good idea? necessary? and what temperatures should I avoid, and what temperature should I try to acheive to get satisfactory results?
Secondly, I should Ideally be able to dim it down to a reduced light and power output. So that I can reduce the light output (temp) if it shuts down due to tempereature (less light = better than no light), and to not blinden my competitors in an oncoming track. This solutions hould also preferrably reduce the total power consumption to 35W or less in case I'm experiencing problems with battery charge.
How would I go about hooking this up? Preferrably to my existing lighting circuit which has the following cables: GND, 12VAC constant, 12VAC high, 12VAC low. Id' like to be able to between high and low.
I guess I need som resistors or something. And/or a relay? (hope not) Lower the input voltage on the driver somehow? Its rated for 9-24V, so possibly it wil dim when below 9v?
At last I need to water/shockproof these components to a certain degree. Im planning to encase the driver and the transformer in some kind of simple housing at seal it up with a non-conductive glue/silicon. How will that affect temperature build up in those parts? Not an issue?
Long post, but thanks a million for all the help I can get! Right now I'm at a stand still not knowing how to proceed, but I really like to get things going, and see how it turns out before the evenings are full of sunlight again.
-Stian
I'm all new to the whole DIY LED, electronics, flashlight thing, but have found me an intersting project that I simply need some input on to get started. I'm an mechatronical engineer, so I know some basic stuff about electronics, and can hopefully follow your techy discussions.
So here's the ting. I'm an enduro driver, and at this time of the year it gets quite dark here in Norway (and snowy and cold, but thats a different discussuion). In a moment of weekness, or strength, depending on how you see it, I found it to be a cool idea and cheap project to try to put a 50 LED chip inside my enduro headlight instead of the 35W halogen buld thats barely glowing. I ended up buying the following components:
50W led and driver
http://www.ebay.com/itm/261727353516
AC-DC converter
http://vod.ebay.com/vod/FetchOrderD...82603&transid=1217008707014&viewpaymentstatus=
Headlight mask
http://www.ebay.com/itm/12V-35W-BLA...ash=item3aa521df88:g:bJ0AAOSw1vlUx25n&vxp=mtr
The plan is to place the led so that is shines through the whole where the bulb normally sits. It fits quite perfect actually. (This is only for off-road use). My bike has a battery and strater motor, and hence a DC circuit. I'm however not 100% sure of the stator output, but I think it is 55W, so in order to ensure that I do not drain the battery, I will connect the AC-DC converter to my current lighting circuit which is 12V AC. (at least then I think I don't steal from the battery, only in worst case take all the juice needed to charge it?)
Now that it's all here, and I've done some more reading i realize i have a couple of questions I can't really figure out.
Firstly, and most importantly there is the temperature issue. This has to be a fairly rugged design, and I don't want to use active cooling. I also don't have that much space, So I don't want the passive cooler to be any bigger than necessary. The headlight will mostly be used during fall/winter in relatively cold ambient temperatures (+10 - -20°C), and there will probably be a certain amount of airflow, though nothing like highwayspeed or a dedicated fan. So what I can't figure out is how hight temp I can allow the LED to get before it gives in, and where I should try to measure this temp. I intend to make a test setup with the heatsink I have, and see how it goes and measure the temp.
I also though of installing a thermoswitch embedded between the led and the sink (or on the sink only?), but don't know for what temp i need the switch to be. This would be only to shut it off in order not to fry. Something like this maybe?
http://www.ebay.com/itm/2-Pcs-Tempe...560825?hash=item35e4a933f9:g:uaQAAOSw-vlVlhGJ
So.... Good idea? necessary? and what temperatures should I avoid, and what temperature should I try to acheive to get satisfactory results?
Secondly, I should Ideally be able to dim it down to a reduced light and power output. So that I can reduce the light output (temp) if it shuts down due to tempereature (less light = better than no light), and to not blinden my competitors in an oncoming track. This solutions hould also preferrably reduce the total power consumption to 35W or less in case I'm experiencing problems with battery charge.
How would I go about hooking this up? Preferrably to my existing lighting circuit which has the following cables: GND, 12VAC constant, 12VAC high, 12VAC low. Id' like to be able to between high and low.
I guess I need som resistors or something. And/or a relay? (hope not) Lower the input voltage on the driver somehow? Its rated for 9-24V, so possibly it wil dim when below 9v?
At last I need to water/shockproof these components to a certain degree. Im planning to encase the driver and the transformer in some kind of simple housing at seal it up with a non-conductive glue/silicon. How will that affect temperature build up in those parts? Not an issue?
Long post, but thanks a million for all the help I can get! Right now I'm at a stand still not knowing how to proceed, but I really like to get things going, and see how it turns out before the evenings are full of sunlight again.
-Stian
