I understand how to calculate the value for a current limiting resistor for an LED. If I plug in the numbers for some typical LEDs I get somewhere between 100Ω and 150Ω for a current limiting resistor with a 5V supply. But looking at various projects, I have seen anywhere from 220Ω to high as 1KΩ for projects with a 5V supply.
Why such a huge range of resistors? The projects I have seen simply mention LED so I would think it was typical LED. Is there a rule of thumb for padding the value of the resistor? I do know that you round up to the next highest common value. But any other rules of thumb?
The LEDs I have selected all have a operating voltage of 2.5 volts and an operating current of 25ma. If I am doing my math correctly (cheating using a resistor calculator), I get 100Ω as my current limiting resistor.
Did I do my math correctly? Do I need to pad anymore?
What is the difference between the various types of LEDs, water clear, diffused, transparent etc ? Is there some place that shows this?
Why such a huge range of resistors? The projects I have seen simply mention LED so I would think it was typical LED. Is there a rule of thumb for padding the value of the resistor? I do know that you round up to the next highest common value. But any other rules of thumb?
The LEDs I have selected all have a operating voltage of 2.5 volts and an operating current of 25ma. If I am doing my math correctly (cheating using a resistor calculator), I get 100Ω as my current limiting resistor.
Did I do my math correctly? Do I need to pad anymore?
What is the difference between the various types of LEDs, water clear, diffused, transparent etc ? Is there some place that shows this?