Gikfun Photoresistor GL5516 LDR Photo Resistors for Arduino (Pack of 20pcs) EK1412

I used these in a compressor foot pedal from PedaPCB and they work perfectly. Thanks.

These are not GL5516s. I tested dark resistance on every one and had only 2 that were less than 2M; one that was 25k and one that was broke. Some had readings >10M.

These measure allll over the place, most with dark resistance around 3-6 Meg, some well over that. I got maybe one or two LDRs in this whole pack that were anywhere near the spec of an actual GL5516

Bought these for the PIR sensor HC-SR501.Under the white dome are thru-hole pads labled LR. Install the LDR to these pads.When this LDR is installed the PIR will be disabled when daylight hits the white dome.I measured about 2.5K in the light and 2.5M in the dark.

These LDRs are not GL5516. The datasheet for GL5516 specifies 500k dark resistance, all 20 I received measure well over 2Meg. Supply chain and semiconductor shortages clearly won't stop anyone from trying to turn a profit with components that don't have markings, if you didn't measure these you'd probably never know they were the wrong component and just assume some other part of your circuit is the problem. I'm sure all the previous positive reviews are still valid and that they received the correct parts, but as of the date writing this I would be skeptical about buying this specific component anywhere, this is the second place I've gotten the wrong part from.

Good value and effective.Small in size but neat and functional.

It was not clear from the seller what resistance these items were, nor their actual size, so I was pleased that they were exactly what I wanted, about 20kOhm when dark and 4 mm in width.

all good

I foolishly assumed that these photosensors were normally open, i.e. they would complete a circuit when there was no light, but they close the circuit when they "see" light. My fault, but I can't think what I can do with them. I was hoping to use them to switch on an LED when it went dark.