LED Voltage Drop Fluctuation: Investigating the Cause

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SUMMARY

The discussion centers on the voltage drop fluctuations observed in a white LED circuit with a potentiometer. The user reports a voltage drop of approximately 3.8V at minimum resistance and 2.5V at maximum resistance, despite expecting a steady drop of around 4V. This inconsistency is attributed to the characteristics of the LED and the influence of the potentiometer on the circuit's overall resistance and current flow. Participants suggest reviewing the LED's datasheet for specific forward voltage (Vf) specifications to better understand these variations.

PREREQUISITES
  • Understanding of LED forward voltage (Vf) specifications
  • Basic knowledge of circuit design and components
  • Familiarity with potentiometers and their function in circuits
  • Ability to read and interpret electronic component datasheets
NEXT STEPS
  • Review the datasheet for the specific white LED used in the circuit
  • Research the effects of resistance on LED current and voltage drop
  • Learn about circuit analysis techniques, such as Ohm's Law
  • Explore the impact of different types of potentiometers on circuit performance
USEFUL FOR

Electronics enthusiasts, hobbyists building LED circuits, and anyone troubleshooting voltage drop issues in LED applications.

asa!!
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hi i have fixed a simple circuit for lighting up a led.i have included a potentiometer. as the led is white i know that the voltage drop of the led is around 4v.when the potentiometer is at min resistance the voltege drop is actuallu around 3.8v.the problem is that when i turn the potentiometer at maximum resistance the drop is around 2.5v.I thought that the voltage drop is steady for each led and does not fluctuate.could anyone explain me why that happens?thank you
 
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asa! said:
hi i have fixed a simple circuit for lighting up a led.i have included a potentiometer. as the led is white i know that the voltage drop of the led is around 4v.when the potentiometer is at min resistance the voltege drop is actuallu around 3.8v.the problem is that when i turn the potentiometer at maximum resistance the drop is around 2.5v.I thought that the voltage drop is steady for each led and does not fluctuate.could anyone explain me why that happens?thank you
Please post a link to the datasheet for your LED. If you can't figure out the Vf specs, we can help you do that.
 

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