Something I was planning to mention, but that didn't make the cut: regular LEDs work as (poor) photodiodes too, with a LED-color-specific spectral response. Experimental results can be found here:
As for photodiode response times: they're usually given in the spec, but values between 1 and 100 nanoseconds are common for small devices. Some tiny BGA units will have response times as low as 100 ps; while large, specialty sensors may be as slow as a microsecond or so.
> That said, LDRs are not especially linear and tend to be excruciatingly slow, with response times measured in hundreds of milliseconds. They’re OK for sunlight sensors and other simple devices, but they’re not as popular as they used to be.
And LDRs are a must have to build your own vactrols :-)
Something I was planning to mention, but that didn't make the cut: regular LEDs work as (poor) photodiodes too, with a LED-color-specific spectral response. Experimental results can be found here:
https://learnmaketeachshare.org/sensors%20and%20circuits/2018/10/30/using-leds-to-measure-narrow-spectral-bands.html
As for photodiode response times: they're usually given in the spec, but values between 1 and 100 nanoseconds are common for small devices. Some tiny BGA units will have response times as low as 100 ps; while large, specialty sensors may be as slow as a microsecond or so.
Thanks again for this a nice article!
> That said, LDRs are not especially linear and tend to be excruciatingly slow, with response times measured in hundreds of milliseconds. They’re OK for sunlight sensors and other simple devices, but they’re not as popular as they used to be.
And LDRs are a must have to build your own vactrols :-)
Thank you for clearing up the differences between some components that have long confused me :)