Winston Todge
|
| posted on 28/8/06 at 05:02 PM |
|
|
DIY LED rear light units...
I'm intending on using a chip from Maxim to drive a couple of LED arrays...
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4883
I have sourced relevant LEDs from Avago similar to these...
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=1058439
A question I have to others that have looked at this before is whether lens covers have to be E marked and adhere to any other regulations?
Is this idea plausible? This is the sort of thing I want to replicate...
http://www.led-bulbs.com/eshop/10Expand.asp?ProductCode=36
Anyone know of a place to get lens covers also?
I know there's a few electronics peeps out there who may be able to shed some light on this...
Ta,
Chris.
The aim is to reproduce something like this... But for a little less!?
http://www.nfauto.co.uk/lights_reflectors_repeaters.htm
[Edited on 28-8-06 by Winston Todge]
|
|
|
|
|
RazMan
|
| posted on 28/8/06 at 05:43 PM |
|
|
Not sure about E marks on lenses - but as long as they are 'bright enough' Mr SVA should pass them.
The 60 led clusters look very suitable and I reckon if you put a diffuser type lense over the top they would have a good chance of passing. £20 each
is very reasonable too and I doubt that you could build them for much less.
The main problem I found with led lights is the narrow viewing angle - the lights practically dissappear when viewed from an angle, especially in
daylight.
I bought some excellent led replacement bulbs on Ebay which work very well, although I havent taken them to SVA yet,
 
Rescued attachment 1157_flux1.jpg
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
SixedUp
|
| posted on 28/8/06 at 06:16 PM |
|
|
Looks like you're on all the right lines with that driver chip. The only questions in my mind are:
(a) Will Mr SVA accept non-E-marked covers?
(b) Can you get the viewing angle wide enough?
(c) Can you make the LEDs appear bright enough for use in daylight?
The commercial offerings have always struck me as taking the p!ss in price terms, as the price of the components is absolutely minimal (Red/Yellow
LEDs are 10-15p each at retail for Gods sake).
Let us know how you get on.
Cheers
Richard
|
|
|
Confused but excited.
|
| posted on 28/8/06 at 06:41 PM |
|
|
Chris,
Have a look through the stock on this site:
LED1.co.uk
I have had some leds from them that are savage.
They will damage your eyes if you look directly at them.
I have one with it's resistor for 12v operation, if you want it to play with. They also do them in red.
If memory serves it is either 1 or 5 watt. I bought both and don't know what this one is.
I cannot be sure but I think the viewing angle is 140 deg.
Sorry to be so vague but I had quite a few of differing specification.
Send me a U2U with your address if you want it.
Tell them about the bent treacle edges!
|
|
|
Winston Todge
|
| posted on 28/8/06 at 06:45 PM |
|
|
Cheers for the pointers so far chaps...
I've actually sourced all the required LEDs (very cheaply - read free - for research reasons at work...  ) and they come with a 120 degree
viewing angle which should suffice. The brighter LEDs are 30 degrees but I think this maybe too shallow an angle.
The brightness issue shouldn't be a problem! I've hooked a small array up and they are blinding to say the least and draw tiny amounts of
current... 
The best bit about the Maxim chips would be beng able to use the PWM input to dim the lights for a tail light facility and then switch to full whack
when you press the brake pedal.
I am going to have a ring of amber LEDs around the outside of the circle for the indicator and the centre as tail/brake lights.
I'm hoping it should work okay. I just can't see from the Stella Lighting examples how they've resulted in two brightness levels
from the circuitry they have on there...
Chris.
|
|
|
Howlor
|
| posted on 28/8/06 at 07:31 PM |
|
|
I have LED rear lights on everything. The SVA man was OK with the Fog with no lens and no E mark but he pulled me up on the brake/rear lights as he
said the brake needed to be a separate filament to the rear light, not just go brighter.
Steve
|
|
|
RazMan
|
| posted on 28/8/06 at 09:39 PM |
|
|
quote:
Originally posted by Howlor
I have LED rear lights on everything. The SVA man was OK with the Fog with no lens and no E mark but he pulled me up on the brake/rear lights as he
said the brake needed to be a separate filament to the rear light, not just go brighter.
Steve
That mean my 'relacement' led bulbs will fail then  They have an internal resistor which is bypassed for the brake light. Did you have
to put conventional bulbs in for SVA then?
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
Chippy
|
| posted on 28/8/06 at 10:46 PM |
|
|
Best bet is to fit cheepo lights that comply, get SVA'd then you can fit what you like, as long as it will pass MOT. If you dont want to put
screw holes in the bodywork, stick them on with mastic, which will hold them secure but will come of, (with a bit of elbow grease), fairly easily. ATB
Ray.
|
|
|
