LED Circuit Demo

Congratulations on building a working circuit, but electronics should rarely go "boom", and only if they are designed to do so. Still would be a waste of completely good components and materials though :/

Remember this is only a simulation. Real LEDs may take a completely different current before burning out. YouTube has examples.

The LEDs on EC are set to blow at twice their current setting.....Your default setting here is 20mA so it will blow when the resistor is reduced enough to allow 40mA to flow.

Didn't know that. Is there any way to tell what mA an LED is then? Or blow it up and half the current draw? 😳

Best to refer to the specs when buying, but if you are wondering about a little general purpose LED that you have lying around wanting to use it on a breadboard etc, then think in terms of always keeping its current just under 20mA with a series resistor. That resistor size choice will depend on the supply volts....practise obtaining that here on EC. The default voltage across the LED is 2v there. Those values are a little flexible, you don't have to be exact. Remember V=IR , so if you know that resistor R, and you measure the V across it, then you have the current I answer, since that is the same through the resistor and the LED. An LED does not have a fixed resistance like that of an incandescent bulb, so don't expect a simple calculation as though it were a fixed resistor in series.

As an example for the above schematic.... We always want to use I=0.02 amps and use v=2  volts drop across the standard LEDs in our calculations ....so once we know V the supply volts, then R=(V-v)/I  ....  so here above we have R=(3-2)/0.02 thus R=50 Ω as seen..... the (V-v) is the volt drop across our resistor which we need for the calculation. Example2... if supply volts V=10 then R=(10-2)/0.02  thus R=400 Ω .... so we can always calculate an approximate suitable resistor for these standard LEDs just by knowing the supply volts.

For those who hate calculations..... just alter the battery to yours in the original schematic here, then alter the resistor setting there until 20mA is seen throughout....that approximate resistor value seen then should be good to go.