znomit
Enlightened
Re: Dynamo lights for injineers
Is it time to change the thread title yet?
Is it time to change the thread title yet?
Should I be concerned that the LT4320 has a minimum input of 9V, given that I am looking to improve low speed performance & have a target of ~5.3V ?.
I seem to have lost sight of one of my design goals - the KISS principle.Is it time to change the thread title yet?
Ride harder is always an option At the moment I am annoyed by a slow strobe from the LED without the super cap at ~10 km/h (6.25 mph). The 5.3V was a figure I plucked from 2 x XM-Ls at 0.15A. I can probably get by with a schottky bridge rectifier, esp at the low Vf found by Znomit, just by switching the two rear red leds out at low speed, because (1) the red standlight is bright & (2) I have a li-ion powered red XP-E on my helmet.how slow do you need/want to go, and how much light do you need at that speed? If you are looking at 5.3v, then you've just got one white LED and a red LED in series, I'm guessing. That's lower than what I've got, with two white LEDs and some paralleled 1.8v red 5mm LEDs in series. My light works down to 3.5mph, albeit dim and flickering. I think you might get by with a bridge rectifier made of schottky diodes.
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As thoughts often lead onto other thoughts, I am now wondering whether this is a way to have a flashing taillight without flashing the front lights - ie have the lights physically spaced apart & set up the timing so there is a brief overlap when both are on, or more importantly, no time when neither light is on.