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LED power usage
Moderators: adafruit_support_bill, adafruit

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LED power usage

by Derek_7 on Tue Jul 14, 2020 7:07 pm

I’m wanting to connect four 5mm LEDs together. One Green, one Red, and two white. The total voltage comes out to be 12.3V. If I connect this to a 9V battery, will the LEDs even turn on or will they just be very dim?

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Re: LED power usage

by adafruit_support_bill on Tue Jul 14, 2020 7:12 pm

If you connect them all in series, you would probably get some light out of them.

If you want them at full brightness, you could wire them in parallel (or series-parallel) with appropriate current limiting resistors.

https://www.digikey.com/en/resources/co ... s-resistor

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Re: LED power usage

by Derek_7 on Tue Jul 14, 2020 8:11 pm

Ok, one more question. Would it be possible to connect multiple resistors together. i.e. a 75 ohm and a 100 ohm in a parallel circuit.

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Re: LED power usage

by adafruit_support_bill on Tue Jul 14, 2020 8:45 pm

You can have multiple resistor & led circuits wired in parallel. The resistor value for each circuit will depend on the forward voltage of the LED it is in series with.

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Please be positive and constructive with your questions and comments.