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Topic: light resistors giving different values (Read 611 times) previous topic - next topic

h3lpm3

I have a breadboard setup with 2 light resistors connected. Both have identical layouts.

One of the light resistors shows a value of ~600 normally and ~250 when I cover the sensor with my hand (real rough estimates here)

The other resistor shows around ~40 normally and ~5 when covered.

I've tried swapping both of the existing resistors with a spare and no change.. so won't be a faulty resistor.

Any ideas on why the values are so different?

My project relies on the values being relatively similar - pls help

MarkT

Light Dependent Resistor or LDR.   They are probably different devices.

Even the same device and you'd expect a large spread in values between devices with LDRs, they are not precision devices in any sense.

For precise light measurement calibrated photodiodes and light sensing chips are used.
[ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]

TomGeorge

#2
Nov 04, 2019, 12:14 pm Last Edit: Nov 04, 2019, 12:15 pm by TomGeorge
Hi,
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.


Quote
I have a breadboard setup with 2 light resistors connected. Both have identical layouts. :o
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Do you have a DMM?
What is your project?

Thanks.. Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

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