Monday, March 20, 2017

Strobe Lights for Velomobiles

Have you ever been almost wiped out when crossing a busy intersection? I have more than once. Now I have to buy a white strobe for the front just to get across the street! In the day light!!!

These are much smaller than I expected. The light face is only 2”x 5/8 inch for the 3 L.E.D. units. And you need 2 water proof switches (for a bicycle), one being a “momentary” contact to change the flash pattern.

9 watts (3w each bulb)

Wattage is not the only thing that will determine the
brightness. The 'super-bright' lights above have shaped
beams, so they may not be seen as easily as this one
that does not shape the beam. And at only 4 watts each
unit saves more than half the power as a 9 watt unit.
However if you can get the shaped beam into the eyes
of the car drivers, they will see you much better.
I am using these 4watt units on the side of my bicycle.

with only four watts you can use a smaller battery pack:

12V 2000mAh NiMH Battery Pack
Tenergy is the worst brand to use

Lithium Ion cells are much cheaper over a long period

For Lithium-Ion cells get an IMAX B6 old style charger.

The new ones will not charge through electric protection circuits. But if you don't have that detail just get newer one, but it still needs the ballance wires. The old one does not.

for a truck tail light with LEDs

This can be a complex project

to change modes

Chrome Glow 12V Waterproof Push-
Button On-Off Switch with 12" Leads

If you are building a pack, and you want to use a circuit board, the electronics are so small now these protection boards have balance charge circuits built in, so it would be even safer to charge. But the new I-Max B6 will not like the confusion of more circuits.
The I-Max B6 charger (old style) charges through the protections circuits, even though the instructions say that it will not; I set mine on 3 cell 3.6 volts per cell to make the cells last longer.
They should be charged to no more than 4.2v or even 4.1v or even less if possible. It has recently been proven that the longer a battery cell holds a high voltage the faster it will degenerate. So if you want a full charge of 4.2 volts, use it right a way. If you charge them to something like 5 volts each or more, you are begging for trouble!!!
3 Cells in series can be charged faster than single cells because they have more resistance that way. I set my charger to 1 amp. So a 4 cell pack could charge faster at a higher voltage. (1/3 volt each cell) if you need the charge faster try it at a higher voltage. But if using cheap Chinese cells charge them in a steel ammo box!! If they produce enough heat to feel you may have dangerous problems. If the pack does not have the wires to the balance plugs the cells will even them self's out after a while so don't worry about that.
The new battery chemistry {LiFePO4} is safer than the older 18650 Li-ion cells. But I do not know how they would charge in an I-Max B6. NiMH is much safer but much heavier. 

more info about lights

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