I said in another thread that i would document the project of making some decently high-power LED lights , hopefully in time for the coming winter months.
Its something that has been on my mind for at least a year now. I sometimes feel that bright lights from brand names are over priced for what they are and me being a typical tight fisted jock twat, i resent paying it.
At the start of last winter i thought about doing it, but didn't. Now this year, I feel that the whole scene is reaching a decent level of maturity such that a project like this is feasable.
( Whether I make these lights for less than what i could buy off the shelf will remain to be seen. )
The daft thing is that my commute in the future will likely become a thing of a the past should i change jobs, but none the less, i still want to do this project and complete it.
So here goes. I'm starting right from the very very beginning here. I dont even have any of the fundamental parts delivered yet, but i have ordered them. I aim to document all the stages of what i go through. Hopefully this will allow people to gain the courage to do their own thing too.
Principle Requirements
My commute is typically about 12miles in each direction. There are 2 routes I can choose. The first is a busy A-road with a decent amount of traffic. Some sections are lit and in the dark, cars provide a decent amount of light to cycle by in addition to my own lights. Typical travel time is 40mins. The second is a single track road which is significantly quieter
in terms of traffic, but is completely unlit ... think pitch black for miles. Travel time here is about 1 hour.
In the darkest period of winter, both journeys could be in the dark, although in the mornings, it quickly lightens up to the point that lights are not needed to see by, but are better on to be seen by. Ideally i need at least 2hrs of good burn time.
Factor #1: Front lights need to be good enough to see by for 2hrs or more in complete darkness at reasonable speeds
Seconly, i want to essentially get home, unplug the battries, plug them into the mains and recharge them overnight ready for the next day.
Factor #2: Decent ability to recharge the lights without much fuss.
Lastly, I have more than one bike which I use on the commute, so i need to be able to swap the lights between bikes without fuss.
Factor #3: Easily swappable onto any bike.
So those are my goals. Lets go onto the theory.
High Power LEDs : Current = Brightness
OK, here goes. This is the point where I initially went
trying to get my head round it all in the early stages.
Over the last few years, a new breed of LED light has become really very popular, i suppose they are nick named emitters, but they are made by all sorts of companies. The earliest big name was probably Luxeon. They come in 2 main forms. Emitter only, which is a tiny wee blob with little solder tabs sitcking out from it, or on a star shaped pcb ( which is the same blob, just soldered onto a heatsink style circuit board with much bigger solder tabs )
These over the years have increased both in power and intensity. The current ones pump out 240 lumens of light. ( As I understand it, this is a bit more than a 10W halogen bulb ). The current best of breed seem to be Cree and Seoul emitters. I chose Seouls.
Now ... whilst most people think in terms of Voltage, when it comes to LED emitters and their brightness, Current ( Amps ) is the primary factor to brightness from an LED.
The LED do need voltage to get them to switch on in the first place ( typically approaching 4V ) but controlling the brightness comes from controlling the current. The more current you push through these things, the brighter it gets. The typical max current you pump through these emitters is about 1Amp, or 1000milliAmps, although its pretty common to run then at 700mA to preserve them a bit more and not work them so hard. So for these high power lights, its best to have a method of controlling the current.
There are 2 main methods of controlling this current.
1 type is where you provide more voltage than is needed. The controller then only pulls enough from the battery to generate the correct current rating. So if you have an LED at 4V inline with a controller needing 2V, then you need to supply more than 6V for the controller to function properly. The more LEDS, the more volts you need though. So for 2LEDS, i'd be looking at 10V supply or more.
The second type is a boost style. This is where you supply less than the necessary amount of volts, but the controller generates a high voltage out of it in pulses which equates to the output equalling the correct current. The downside of this is that for generating 1000mA of current on the output, you may be pulling more than that from the battery . . 1100mA
...
Its something that has been on my mind for at least a year now. I sometimes feel that bright lights from brand names are over priced for what they are and me being a typical tight fisted jock twat, i resent paying it.
At the start of last winter i thought about doing it, but didn't. Now this year, I feel that the whole scene is reaching a decent level of maturity such that a project like this is feasable.
( Whether I make these lights for less than what i could buy off the shelf will remain to be seen. )
The daft thing is that my commute in the future will likely become a thing of a the past should i change jobs, but none the less, i still want to do this project and complete it.
So here goes. I'm starting right from the very very beginning here. I dont even have any of the fundamental parts delivered yet, but i have ordered them. I aim to document all the stages of what i go through. Hopefully this will allow people to gain the courage to do their own thing too.
Principle Requirements
My commute is typically about 12miles in each direction. There are 2 routes I can choose. The first is a busy A-road with a decent amount of traffic. Some sections are lit and in the dark, cars provide a decent amount of light to cycle by in addition to my own lights. Typical travel time is 40mins. The second is a single track road which is significantly quieter
in terms of traffic, but is completely unlit ... think pitch black for miles. Travel time here is about 1 hour.
In the darkest period of winter, both journeys could be in the dark, although in the mornings, it quickly lightens up to the point that lights are not needed to see by, but are better on to be seen by. Ideally i need at least 2hrs of good burn time.
Factor #1: Front lights need to be good enough to see by for 2hrs or more in complete darkness at reasonable speeds
Seconly, i want to essentially get home, unplug the battries, plug them into the mains and recharge them overnight ready for the next day.
Factor #2: Decent ability to recharge the lights without much fuss.
Lastly, I have more than one bike which I use on the commute, so i need to be able to swap the lights between bikes without fuss.
Factor #3: Easily swappable onto any bike.
So those are my goals. Lets go onto the theory.
High Power LEDs : Current = Brightness
OK, here goes. This is the point where I initially went
trying to get my head round it all in the early stages. Over the last few years, a new breed of LED light has become really very popular, i suppose they are nick named emitters, but they are made by all sorts of companies. The earliest big name was probably Luxeon. They come in 2 main forms. Emitter only, which is a tiny wee blob with little solder tabs sitcking out from it, or on a star shaped pcb ( which is the same blob, just soldered onto a heatsink style circuit board with much bigger solder tabs )
These over the years have increased both in power and intensity. The current ones pump out 240 lumens of light. ( As I understand it, this is a bit more than a 10W halogen bulb ). The current best of breed seem to be Cree and Seoul emitters. I chose Seouls.
Now ... whilst most people think in terms of Voltage, when it comes to LED emitters and their brightness, Current ( Amps ) is the primary factor to brightness from an LED.
The LED do need voltage to get them to switch on in the first place ( typically approaching 4V ) but controlling the brightness comes from controlling the current. The more current you push through these things, the brighter it gets. The typical max current you pump through these emitters is about 1Amp, or 1000milliAmps, although its pretty common to run then at 700mA to preserve them a bit more and not work them so hard. So for these high power lights, its best to have a method of controlling the current.
There are 2 main methods of controlling this current.
1 type is where you provide more voltage than is needed. The controller then only pulls enough from the battery to generate the correct current rating. So if you have an LED at 4V inline with a controller needing 2V, then you need to supply more than 6V for the controller to function properly. The more LEDS, the more volts you need though. So for 2LEDS, i'd be looking at 10V supply or more.
The second type is a boost style. This is where you supply less than the necessary amount of volts, but the controller generates a high voltage out of it in pulses which equates to the output equalling the correct current. The downside of this is that for generating 1000mA of current on the output, you may be pulling more than that from the battery . . 1100mA
...
