By variing the resistor we could increase the current, so that the led gives a last smoking signal :)
Please kids don't try this at kome ;)
What we learn from this :
- allways limit the current !
20 mA is a good value
To calculate the resistors value we use the fixed values
Maximum current: 20 mA
LEDs voltage : 2 V
So we can calculate
Our block batterie that we use has 9 Volt.
The Led takes 2 Volt, so we need to handle 9 V - 2 V= 7 V
at the resistor.
The current is calculated by Ohms Law
I = U / R
in our example
0,02 A = 7 V / ? Ohm
This gives us 350 Ohm as the resitors value.
