Bike light on night rides

[Svendus]

We just wonder if there is a low volt outlet on the 48 volt Cruise-Controll



Wirering diagram




Best regards, Svend Nielsen

[Helgeo]

For driving LED's it is best to use a constant current source, such as this one:http://www.led1.de/shop/product_info.php?pName=solarox-pwmconstant-current-source-ksq350-for-power-leds-350ma-940v-dimmable-p-1155&cName=constant-current-sources-c-112

This one supports input voltages between 9 and 40V, so it is perfect for a 36V system, but it could also be connected to one 24V bank of a 48V system.

[Svendus]

Led spotlight 12 volt



Wikipedia - LED-Spotlight

Wonder what happens if we use one one battery outlet of the four 12 volt gel batteries on the bike   

[Svendus]

For driving LED's it is best to use a constant current source, such as this one:http://www.led1.de/shop/product_info.php?pName=solarox-pwmconstant-current-source-ksq350-for-power-leds-350ma-940v-dimmable-p-1155&cName=constant-current-sources-c-112

This one supports input voltages between 9 and 40V, so it is perfect for a 36V system, but it could also be connected to one 24V bank of a 48V system.

All right thank you  I think there should to be a 12v outlet which would be suitable for use with 12 volt LED's...

[Svendus]

I've done this but rotated the batteries after each ride. The battery with the light gets a deeper discharge ans since the cutoff read the total voltage you may have an imbalance that will shorten the life of the pack. I've also tried carrying a light battery and that works great - especially when I use my unmotorized bike.

we are building two 3 wheel bikes with a battery weight of 4 x 6.6 kg (two front wheels) the batteries situated between the front wheel in a low position in a box

[Perbear]

The smart way to do this is to use a step-down converter that takes the full battery voltage and converts it to current controlled lower voltage. Then the current limited voltage can be applied directly to high power LEDs connected in series. Most Step-down converters handle only 40V input, but some handles up to 60V and a few handles 100V. It is normal to limit the current to 350mA to supply 1W LEDs.  www.ebikes.ca sells ebike LED lights with integral step-down converters that can run on an input voltage between 24 to 90 volts.

If you want to make such step-down converter yourself you can start by examining the LM 5008 and LM 5009 ICs from National Semiconductor. Those ICs plus a few capacitors and a coil are perfect for 150 and 350 mA LEDs.

[Perbear]

I've been using 20 watt 12 volt MR-16 Halogen with 120 lumens I have 6 new 130 lumen LEDs in an integrated heat sink housing left for $39.95 each plus shipping. Voltage has to be limited to 14 volts. You can do this with a 5 watt Zener diode.

Yes, it will work but that 5W Zener is only good if you use 3W at 12V (250 mA or less). And it will waste 5W, not very efficient. This is a much more efficient solution:
http://www.national.com/pf/LM/LM3404.html

It can easily source 20W with LED using a 36V battery with an efficiency of 90%. This IC can handle up to 42V (LM3404) or 75V (LM3404HV) and supplies up to 1A. National Semi also have low current versions, LM3402 and LM3402HV that delivers up to 500mA, perfect for several 350mA LEDs in series. They even sell ready made demo kits.

[Svendus]

48 volt solution



Four  1,5w 12 volt 50 mm led serial connected