Is it really OK to supply more current than what the component is rated for

currentpower supply

In this heavily upvoted answer the answerer states that it is okay to supply a component with more current than what it's rated for. The analogy is that (paraphrasing here) "If Johnny wants to eat two apples, he'll only eat two regardless of whether you give him three or five, etc."

However, one of the most basic circuits you can possibly make is to power an LED from some power supply. Since most power supplies provide a current that is higher than what most LEDs can handle, you must put a resistor in front of the LED in order to not burn it out.

So which is it?!? Can someone explain to me when/where/how it is/isn't okay to provide higher (and lower, for that matter) current than what a component is rated for?

Best Answer

To answer the title of your question, the answer is no. It is not ok to supply more current to a component than its rated value.

However, it is ok to have a voltage power supply rated for more current than the components rated value because the component will draw as much as it needs. If you are pushing more current into (forcefully) the component, then the component will exceed its rated value, heat up and be destroyed. Such as if you use a constant current source or you use a large voltage (which will cause more current to flow). But if you use the rated voltage, then the load will only take what is required, regardless of how much current is available to be drawn from the source.

The difference is in how you word your question.