Optical density led sizing

Hardware, PWM, and Optics
1

Hello,

continuing my mission of making an OD probe for a custom reactor. I am wondering what the voltage and current requirements are for the LED used for OD measurements is thats connected to channel A so that I can use a similar one. I need to downsize to 3mm for space limitations. Put a multimeter to the pins and saw 5 V. Intensity % controls mA. Is there a conversion from % to mA?

2

Hi @rafik.n,

The LED outputs up to ~100mA, so 1% ~ 1mA. And yes, the voltage is tied to the RPi’s 5V rail (or more accurately, the voltage of the PSU being used).

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