QuoteCoin cells can only supply a few mA Is this only a behavior of coin cells? What about AAA batteries?
Coin cells can only supply a few mA
I don´t understand (in the link attached bellow) how she can handle this amount of leds without using transistors and with the same power supply I´m now trying.
QuoteI don´t understand (in the link attached bellow) how she can handle this amount of leds without using transistors and with the same power supply I´m now trying.I agree. The LEDs are just an LED and current limit resistor, that many in parallel would seem to be drawing way too much current thru an IO pin.
It doesn't say button cell, shows a AAA battery & Lilypad power supply.
LED modules are simple LED/resistor, 100 ohm for the one I looked at, implies near 20mA current draw: (5V - 3.2V)/100 = 18.5mA.
Sorry for being insistent. I know that this set of 8 leds are considered as one led due to being connected in parallel. But if you connect in parallel you keep the drop voltage between those leds, but the more leds in parallel you add the more current you need, right? And each pin only provides at maximum of 40 mA, so i don´t see how she makes it without transistor...
OTOH I wouldn't have thought it was possible to power a Mega328 using a CR2032 (even without LEDs).
Thanks for that. I must have done that late in the day.