[Shotimes] how do flashers work?

[bjshov8]

This is the answer- bulbs can be designed to operate at various voltages,
however the average LED will only operate at relatively low voltages.  If
you give it more voltage you will naturally get more current and more light,
but you will reduce the life of the LED.  Too much voltage and it will flash
just like light bulbs can do.

I've fooled around a little with LED flashlights and it seems that for the
same light output, and LED only needs roughly 1/2 to 1/3 as much current.
The LED tailights that I have seen have a lot of little LED's in there,
probably wired in parallel but if they wired groups of them in series that
could solve the voltage issue.  Nevertheless unless they are much brighter
than the stock bulb then they probalby will draw significantly less current
and have some resulting affect on the operation of the flasher.

BTW, an LED flashlight is a good thing to carry in your SHO for emergency
situations, because it does not have a bulb to fail due to age or vibration.

> A typical LED has a forward drop, Vf of around 2V.  Blue LEDs can go as
high
> as 5V, IIRC.  So the resistor is calculated to drop the remaining voltage
> from the source, 13V in the case of automotive applications, based upon
the
> desired amperage.