What Determines Voltage Changes in LDR Darkness Sensors?

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SUMMARY

The discussion focuses on the operation of Light Dependent Resistors (LDRs) within a voltage divider circuit. Participants clarify that the voltage divider is formed by the LDR and a fixed resistor, with the output voltage taken across the fixed resistor. It is established that as light intensity decreases, the resistance of the LDR increases, leading to a higher output voltage, while increased light intensity results in lower resistance and a decreased output voltage.

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  • Understanding of voltage divider circuits
  • Knowledge of Light Dependent Resistors (LDRs)
  • Basic principles of electrical resistance
  • Familiarity with circuit diagrams
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Electronics enthusiasts, students learning about basic circuits, and hobbyists designing light-sensitive applications will benefit from this discussion.

Eisen
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Here's the circuit-

darkness sensor.JPG


It isn't clear to me which part of this circuit makes the voltage divider and also it doesn't show where the voltage output is on the circuit. Can someone tell me those two things please. Also I don't understand why voltage increases as resistance increases in the LDR and why voltage decreases as resistance decreases in the LDR. Can someone explain that too please. It doesn't give an explanation why on this webpage I'm looking at.
 
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