Question about "current" (I) events.....

Question about \"current\" (I) events.....

Still a little confused about something...... If I have a device, say a 1.5vdc motor that draws .5 mA while operating. If I hook this motor to a AA battery and it runs 45 minutes it should run much longer on D size (able to supply the same current for a longer time) so if I put this same motor on a 1.5VDC lead acid battery, I could just go on vacation and leave it.... So.... to my point....

Are LED's not the same way as long as the supplied voltage is within tolerance? I am a little confused still... I know that more Amphours usually means longer run times if the device has a constant current usage for operation.. So what is the difference, if any, with LED technology.

Thanks
skillet

Re: Question about \"current\" (I) events.....

I'm not sure I understand what you ara asking. YES, larger battery, longer runtime.
Jeff

Re: Question about \"current\" (I) events.....

Let me clarify.... Do lux emitters draw the same amount of current in DD if the voltage is realitvely constant and not over Vf?

Most of the mod brds for these applications are rated in mA, so i was wondering how LED technology was different than any other device that runs on DC voltage..

thanks... hope my question is clearer

skillet /ubbthreads/images/graemlins/tongue.gif

Re: Question about \"current\" (I) events.....

One difference with LEDs that makes them more dangerous to run in direct drive than, say, and electric motor is that as it heats up, its Vf will fall, which results in more current, which results in more heat, which results in more current, etc. until, if the battery can supply the increasing current, the LED will burn up.

Re: Question about \"current\" (I) events.....

Blinded is right, thermal runaway is the killer of LED's. but the answer I wauld say is yes...IF.
ENOUGH heatsinking. And you are not riding the upper edge. I run a couple LUX III mods with single 14500 Li-Ion DD. initial current off the charger is 1.2A but settles to about 950mA after it stabalizes. 950mA, with adiquate sinking, is safe... BTW I was unable to check what the running voltage was at this point.
Jeff