Only 4.86 Volts at PWM Output Pin

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petevree
 
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Only 4.86 Volts at PWM Output Pin

Post by petevree »

Hello,

Do you have a link for a description as to why the Arduino PWM Output voltage drops to 4.86 Volts when an LED and 330 Ohm resistor are added, and remains at the expected voltage of 5 Volts open circuit? Thanks so much.

Pete Vree

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adafruit_support_bill
 
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Re: Only 4.86 Volts at PWM Output Pin

Post by adafruit_support_bill »

The output transistors have some internal resistance, so the voltage drop will be proportional to the current draw.

See the discussion on the topic here: https://forum.arduino.cc/index.php?topic=106346.0

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petevree
 
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Re: Only 4.86 Volts at PWM Output Pin

Post by petevree »

Thank you so much for the prompt reply!

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