DIY LED Signal (UPdates page 4 brake light)

[spenx75]

Originally posted by EmptyVessel@Jan 12 2006, 05:44 PM

if you placed a large resistor parallel the the leds you can proportion the current drawn to feed 10-20ma to the leds and say 200ma to the parallel resistor. so you draw ~220ma in total which maybe make the blinking better.

digging up this thread again...

 

Sorry guys but i dun understand how by placing a resistor parallel to the circuit can increase the current drawn... tot it'll only increase the resistance? paiseh... i hv not elec. background...

 

I'm trying not to temper with the flasher relay... just trying to make a plug n play signal light...

 

thks again guys...

[Limsteel]

Yo Dude you got me thinking about it.. It should be Low resistance... As power is Current x Voltage... In case of High resistance... Current Across the Resistor is low and Voltage is constant.. Thus lower power consumtion...

 

Putting a 1 Ohm resistor can V=IR; I= 12V/1ohm thus 12Amp so Power = Current x Voltage = 12 x 12 = 144Watts... maybe work out your signal light total power and find the required resistor... 3ohm will drop power to 32W.

 

Can't find time to pass the circuit to Spenx75...

[Guest nE0]

An LED signal light might consume like 1watt. But common signal light blinkers are designed to work at 35 to 50 watts (for motorcycles). BEcause LEDs consume so little power, its asif the "bulb" is not there, and the blinker is designed to blink faster if a bulb is blown, letting the rider know.

 

Load equalizers are sold for like $20 to $30, ultra ridiculous prices. Its actually just a resistor connected between (+) and ground to simulate a load, or a signal light bulb.

 

Take P = I X V,

Since V = I X R

I = V / R

P = (V / R) X V

P = V^2 / R

 

Voltage of a bike is say, 14 volts

To simulate a 15watt signal light bulb (Some bikes use 25watts, check yours), 15 = 14^2 / R

R = 13.06 ohms.

 

So head on down to Sim Lim Tower, get a 10watt 13.06 ohm (or nearest value) resistor and hook it up. Tada, $2 load equalizer.

[spenx75]

Tks bros! Will do some calculations n work something out...

[HelmetBOX1605198525]

hw to find out the spec of the led??

i brought the led..

forgot the spec arl;eady...

[MC28]

Originally posted by nE0@Apr 12 2006, 08:52 PM

An LED signal light might consume like 1watt. But common signal light blinkers are designed to work at 35 to 50 watts (for motorcycles). BEcause LEDs consume so little power, its asif the "bulb" is not there, and the blinker is designed to blink faster if a bulb is blown, letting the rider know.

 

Load equalizers are sold for like $20 to $30, ultra ridiculous prices. Its actually just a resistor connected between (+) and ground to simulate a load, or a signal light bulb.

 

Take P = I X V,

Since V = I X R

I = V / R

P = (V / R) X V

P = V^2 / R

 

Voltage of a bike is say, 14 volts

To simulate a 15watt signal light bulb (Some bikes use 25watts, check yours), 15 = 14^2 / R

R = 13.06 ohms.

 

So head on down to Sim Lim Tower, get a 10watt 13.06 ohm (or nearest value) resistor and hook it up. Tada, $2 load equalizer.

Exactly the ans i was looking for..

 

Thanks nEo for pointing this out..Will check on the bulbs later..

[Guest nE0]

Originally posted by MC28@Apr 17 2006, 02:57 PM

Exactly the ans i was looking for..

 

Thanks nEo for pointing this out..Will check on the bulbs later..

No prob

 

I just cringe when I see the prices of load equalizers...

[spenx75]

Thanks Limsteel & nE0! Finally got my signal lites to blink! Hahaha...

 

Got some 5w resistors at SLT @ 80cents each, hooked 'em up n voila...

 

 

Meet up for coffee sometime? My threat...

[Guest nE0]

Originally posted by spenx75@Apr 18 2006, 03:04 PM

Thanks Limsteel & nE0! Finally got my signal lites to blink! Hahaha...

 

Got some 5w resistors at SLT @ 80cents each, hooked 'em up n voila...

 

 

Meet up for coffee sometime? My threat...

Remember to insulate them, else they might melt surrounding plastics.

 

YOu're dissipating around 15 watts, so 5 watts resistors might be alittle overwhelmed. Do check regularly to see if it overheats, I've seen ceremic resistors glow red hot!

[Limsteel]

Make sure you get your calculation correct and get the right power rating... Blow resistor never mind... don;t burn your bike...

[MC28]

Am i right to say that if my bike stock signals is running on 12V18Watts bulbs, i should get a 15Watt 8 Ohms resistor for the aftermarket signals which i'm using??

[adriel]

Hi all.....LED's Guru..... I was reading this thread with interest and happened to dig up an article that I saw soem time back....

 

Is it possible for a novice... or rather complete idiot when it comes to electronic to make some thing like this...(with the right instructions......)

 

http://www.webbikeworld.com/lights/motorcy...t/led-light.htm

[Limsteel]

Simple... only matter of 2 wire... Either Mod or stock signal... just link the LED strip (radiator Signal) to the existing wire of the signal (getting the +ve and -Ve correct OF COS).

[Limsteel]

Originally posted by MC28@Apr 20 2006, 12:15 PM

Am i right to say that if my bike stock signals is running on 12V18Watts bulbs, i should get a 15Watt 8 Ohms resistor for the aftermarket signals which i'm using??

You OEM is 18W but don't forget you got 2 bulb front and back! meaning total 36Watt... inorder to make it blink, you must get as close to this value as you can.

 

8ohm 15watt? The value 8ohm you got it but the do take note that P = V^2/R... Ignore charging voltage constant batt = 12V... Your resistor will produce 18W power... it will blow theoritically (sometimes it doesn't )

 

Don't forget you got 2 bulb totalling 36W... R= 12*12/36 so you should find a 4ohm resistor with at least 36W power rating... else just buy a few 4ohm resistor with combine Wattage of at least 36W. Connect these resistor in Parallel and link them in series with the relay. This is base on you using LED Signal, as LED power consumption is negligible. if you are using lower power bulb then just subtract 36W with new bulb wattage (front and back).

 

All these are based on theory, using other values might work. The above is a guide only. also it is safer to follow... If you bought a 8ohm 15W as planned, it might work. but it is no where near the 36W load (only 18W), under these conditions. the signal blinking rate might not be the desired rate (it is like operating with 1 signal bulb blown). Also the resistor is generating 18W, Rated at 15W, it will not last. Then again it might

[Guest nE0]

The calculation is based on the rider using one pair of low power LED signal light replacements, not front and back.

 

36watt LEDs are HUGE. An easier way would be to pair up two lower powered LEDs in parallel. 3 X 10 watt LEDs would do the job fine.

 

Formula for resistors in parallel is R = [(R1 X R2) / ( R1 + R2)]

 

Take out your secondary school physics textbooks if unsure

[Limsteel]

Originally posted by nE0@Apr 21 2006, 05:14 PM

The calculation is based on the rider using one pair of low power LED signal light replacements, not front and back.

 

36watt LEDs are HUGE. An easier way would be to pair up two lower powered LEDs in parallel. 3 X 10 watt LEDs would do the job fine.

 

Formula for resistors in parallel is R = [(R1 X R2) / ( R1 + R2)]

 

Take out your secondary school physics textbooks if unsure

I am not refer to 36W LED... on each side of our bike... there will be TWO 12V18W (front and back signal), So it should be 36W.

 

I am also refering to the load resistor to attach to the relay to simulate the normal bulb power load...

 

If can get 10W LED then it would be better... I can only find 5W LED at EBAY selling US$10 a piece. 5W LED at 120Lumen!

[Guest nE0]

Eh, i must be tired...

 

I was refering to resistors! Arghhh..

 

Replace LEd with Resistor... should make more sense

 

The calculation is based on the rider using one pair of low power LED signal light replacements, not front and back.

 

36watt Resistors are HUGE. An easier way would be to pair up two lower powered Resistors in parallel. 3 X 10 watt Resistors would do the job fine.

 

I've never came across 10watt LEDs before, the most powerful ones I'm playing around with are 3 watt ones, and they're incredibly (and dangerously) powerful already.

[maxipower]

What u are using are "LUX-III" Luxeon LED from Lumileds (incorrect way the layman term it "3-Watt" LED). For the lastest Luxeon "K2" series, u get [email protected], i.e. 6Watt of power driving the LED, max of 140-Lumens per "K2" white LED out from this set-up...

With proper heatsink factor-in, there are "10-Watt" LEDs around

[Guest nE0]

The K2 series of LEDs seem to be designed for reflow soldering, surface mount etc. More for ease of manufacturing.

 

Light output per watt wise, Luxeon I LEDs still rule.

[maxipower]

http://img197.imageshack.us/img197/1323/osramostar7sk.jpg

 

Osram high power LED...

18V @700mA (~12W)

[Limsteel]

good stuff! available in Sg? How much?

 

custom make for my SV headlight!

[maxipower]

Originally posted by Limsteel@Apr 23 2006, 01:51 AM

good stuff! available in Sg? How much?

 

custom make for my SV headlight!

I got a friend who is in lighting business is working on 6-8 Luxeon LED headlight... not sure whether he can succeed... gotta wait awhile probably

[WANG ZI]

hi sorie guy just wan 20ma is brighter or 30ma is brighter?

If i wan to light up 10 led how much ohm is require using 9v battery?

[Limsteel]

Originally posted by WANG ZI@Apr 24 2006, 05:47 PM

hi sorie guy just wan 20ma is brighter or 30ma is brighter?

If i wan to light up 10 led how much ohm is require using 9v battery?

Dude... you need a simple circuit... follow this link to calculate the Resistor...

however you first need to know the basic specs of the LED you using...

- Voltage required

- Current required

 

after that fill in the blank... I am sure you can't connect all the 10 in series and expect the LED to all light up. You will need to connect them in parallel...

 

http://limsteel.100free.com/led.xls (also in page ONE)

[maxipower]

Originally posted by WANG ZI@Apr 24 2006, 05:47 PM

hi sorie guy just wan 20ma is brighter or 30ma is brighter?

If i wan to light up 10 led how much ohm is require using 9v battery?

I am guess u are trying to make LED lightings on your helmet...

Depend on where your LEDs are from, some lower-end LEDs are made rated @ 20mA & below they can't even take any current above 20mA for pro-long continous driving. If getting the lower-end stuffs, u can forget about "30mA brighter" if u want it to lit-up for more months. The rest is like what Limsteel said, check out the forward driving voltage of the LEDs & decide on driving them in series or parallel