LED''s In Series.....
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Posts: 46,084
One way to look at it is the water flow analogy. If you connect four garden
hoses end-to-end, the same gallons/minute flows through all hoses. It takes
more pressure to get a given flowrate for the four hoses, because of the
added hose resistance. Likewise, the four series LEDs each carry the same
number of electrons/second, (which is amps), passing through each in
sequence. The four LEDS need more pressure, (voltage), to get the 20 ma
flow. If the LEDS were in parallel, you would need to supply 80 ma. at less
voltage.
Hope this helps,
Ray McArthur
> Thank you Nick. Would you expound on why the circuit of four LED's only
> needs a total of 20mA when each LED requires 20mA to be at full
brightness?
> This just isn't making complete sense to me yet and I'm not sure what I'm
> missing.
>
hoses end-to-end, the same gallons/minute flows through all hoses. It takes
more pressure to get a given flowrate for the four hoses, because of the
added hose resistance. Likewise, the four series LEDs each carry the same
number of electrons/second, (which is amps), passing through each in
sequence. The four LEDS need more pressure, (voltage), to get the 20 ma
flow. If the LEDS were in parallel, you would need to supply 80 ma. at less
voltage.
Hope this helps,
Ray McArthur
> Thank you Nick. Would you expound on why the circuit of four LED's only
> needs a total of 20mA when each LED requires 20mA to be at full
brightness?
> This just isn't making complete sense to me yet and I'm not sure what I'm
> missing.
>