Light Dependent Resistor LDR component – Photoresistor

Light Dependent Resistors (LDRs), also called photoresistors, have a resistance that changes based on the amount of light falling on them. The LDRs that I have are the ones that are commonly included in basic electronics components kits.

Brief circuit schematics with short video – List of pages

I assume you already know

Basic properties

Based on my LCR meter testing, they have the property of…

  • Very bright light = almost 0Ω of resistance
  • Very dark = Over 200MΩ (two hundred million ohms)
Light Dependent Resistor LDR schematic symbol with minimum and maximum limits diagram by Electronzap Electronapdotcom
Light Dependent Resistor LDR schematic symbol with minimum and maximum limits diagram by Electronzap Electronapdotcom

Therefore, I suggest that the LDR always be in series with other resistance. The minimum circuit resistance will then be about the value of the other resistance. A parallel resistor can be used to make sure there is never too much resistance.

Video

How to use a light dependent resistor LDR photoresistor component with LED by electronzap

How to set a minimum and maximum possible resistance for light dependent resistor LDR

More details about parallel resistors. Resistors connected in parallel

Good topics to study next

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