Announcement

**ken cool** · 05-07-2010, 06:40 PM

Help Topic Discussion Approved

Old Fox, your call!

**jd666** · 05-07-2010, 07:01 PM

the idea is good, but also remember that even if the bike is switched off, the lights can still be switched on and batteries drained. Also do install a fuse in the circuit just in case of over voltage/over current.

**Puneet1** · 05-07-2010, 07:07 PM

LEDS can only work in lo beam . many expensive cars have leds in Lo beam and even LED projector for Lo beam .

for those HP leds you will need to make sure heating is taken care of as they are quite sensitive .

route wires such that it works only when ignition on .

what rates are you getting the HP led/piece . arent they too expensive

**abhijeet080808** · 05-07-2010, 08:38 PM

Firstly, LEDs will work out to be too expensive for just a low beam. Remember, its totally useless for HB. Say, at 1W 60lm per LED, you will need atleast 25 LEDs to produce 1500 lumens. Say 20 LEDs minimum. That works out to 20W. Where will you get 20W extra from? LEDs do save power but do not work for free!

What about LED alignment and heat-sinking? Would it not be too cumbersome?

There is a reason, why they are not used as h/l yet!

And DC conversions are not at all permanent if you plan a bit carefully.

**rahuldevnath** · 05-07-2010, 08:44 PM

It's not exactly a new idea, but right not viable. Why?
Well,
(1) Cost of Power LEDs are still very high. A 3W is about 180 bucks.
(2) To actually get the equivalent lux we will need about 10 No.s, but again to actually make the road visible we will need about 20 of them.
(3) Reliability - Especially when you have a heat sink attached to them.

It can be done, any one willing to experiment?

Edit: Abhi said it

**Ayson** · 05-10-2010, 01:26 AM

Originally posted by jd666 View Post

....even if the bike is switched off, the lights can still be switched on and batteries drained. Also do install a fuse....

Yes, i will have to place the switch smartly. And also as of now im planning ~4W so even if left on for a night, it would be just half drained. Thank you very much for telling me about the fuse. I hadn't thought of that.

Originally posted by Puneet1 View Post

...need to make sure heating is taken care of as they are quite sensitive .

route wires such that it works only when ignition on .

what rates are you getting the HP led/piece.....

As i have described earlier, i will be mounting them on the aluminium plate. I'm hoping that will be heatsink enough. Plus they will be used only for short durations. I do not want to interfere with the bikes electricals. I am getting INR 80 per LED 1W.

Originally posted by abhijeet080808 View Post

Firstly, LEDs will work out to be too expensive for just a low beam. Remember, its totally useless for HB. Say, at 1W 60lm per LED, you will need atleast 25 LEDs to produce 1500 lumens. Say 20 LEDs minimum. That works out to 20W. Where will you get 20W extra from? LEDs do save power but do not work for free!

What about LED alignment and heat-sinking? Would it not be too cumbersome?

There is a reason, why they are not used as h/l yet!

And DC conversions are not at all permanent if you plan a bit carefully.

As of now i have the stock 35W halogen. That is ~ 20lm/W giving ~700lm. Same for LB and HB. Now even in LB, im not expecting the spread or distance of the HL. What i want, is to see the corner when im taking a hairpin bend at 15-20 kmph or to still see the holes in the road when slowing down for a speed breaker. 4 HPLEDs at 60lm/W is ~240lm. Not much, i know but like i said before these will be pointed to illuminate just 8-10 ft around the bike. Now that you have made me calculate it does seem a bit less. I have mentioned the heatsinking above. About the alignment i think the picure explains it.

Originally posted by rahuldevnath View Post

...
(1) Cost of Power LEDs are still very high. A 3W is about 180 bucks.
(2) To actually get the equivalent lux we will need about 10 No.s, but again to actually make the road visible we will need about 20 of them.
(3) Reliability - Especially when you have a heat sink attached to them.
.....

I think it would be cheaper than a DC conversion. What i think of the flux part is explained above. Heatsink also mentioned above.

**abhijeet080808** · 05-10-2010, 08:25 PM

^^ 4W, the battery can take safely. How effective it is will be known only after you get it done. Best of luck! Do keep us updated. The picture does explain the alignment, but in real life its not that easy - just be flexible enough in your design to realign them if needed.

**Ayson** · 05-10-2010, 10:53 PM

I won't be doing it just like that. I can't risk ~600 bucks without getting something out of it. I have to find out the flux of the LEDs i want to buy. The store selling them don't know that. And i have a few doubts:

1) Is mounting them on the aluminium back-plate enough as a heatsink?

2) Should i mount them with epoxy or by melting solder or any other method, for effective heat transfer?

3) Although the battery is a steady source of current, the charger will supply the battery with varying voltages at different RPMs. Will these fluctuating voltages affect the LEDs?

4) Is there anything i should add to the circuit? Im an electronics dummy.

**abhijeet080808** · 05-10-2010, 11:14 PM

Originally posted by Ayson View Post

I won't be doing it just like that. I can't risk ~600 bucks without getting something out of it. I have to find out the flux of the LEDs i want to buy. The store selling them don't know that. And i have a few doubts:

1) Is mounting them on the aluminium back-plate enough as a heatsink?

It should be

2) Should i mount them with epoxy or by melting solder or any other method, for effective heat transfer?

CPU thermal paste

3) Although the battery is a steady source of current, the charger will supply the battery with varying voltages at different RPMs. Will these fluctuating voltages affect the LEDs?

Use a voltage regulator like 7805 etc

4) Is there anything i should add to the circuit? Im an electronics dummy.

Replies in bold..

**rahuldevnath** · 05-11-2010, 12:03 AM

Check this LED spot light on ebay eBay India: 550Lm 12V High Power LED Spot Light for Motor Bike/Car (item 260581892473 end time 06-Jun-2010 14:08:56 IST)

**Ayson** · 05-11-2010, 12:15 AM

Sorry but what is a 7805? Is it available in small electronics component shops? How much will it cost approximately?

EDIT: I learnt what a 7805 is, but the other two questions still stand. And, without this, will the variying voltages affect the LED life? I want to keep it as simple as possible. I dont mind the variying brightness.

I saw the ebay item earlier. It is too costly, it will be really ugly when mounted and it is a spot light. I need lighting more on the sides. But thanks for the link anyway.

**abhijeet080808** · 05-11-2010, 08:48 PM

^^ Yes, LEDs have a high chance of being fried. To prevent this you will have to drive them at lower than optimum voltage levels by using resistors and hence get lower than max brightness. Better is to use a regulator.

**rahuldevnath** · 05-12-2010, 11:34 AM

Originally posted by abhijeet080808 View Post

^^ Yes, LEDs have a high chance of being fried. To prevent this you will have to drive them at lower than optimum voltage levels by using resistors and hence get lower than max brightness. Better is to use a regulator.

Abhi, what's the tolerance for 7805? Can it withstand 6 to 8 amps?

**abhijeet080808** · 05-12-2010, 08:43 PM

Originally posted by rahuldevnath View Post

Abhi, what's the tolerance for 7805? Can it withstand 6 to 8 amps?

It is rated at 1A max. Upto .5A is safe without heatsinks.

Announcement

High Power LED Cornering and Slow Speed Lamps for AC headlight bikes

High Power LED Cornering and Slow Speed Lamps for AC headlight bikes

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment