It is really awesome ! one of the simplest solution I have seen but looks super effective ! Thanks for sharing it - what could happen when you point it to a computer monitor can it read its at least vertical frequency ? can you help to check if possible. Thankyou for your effort and sharing it !
I'm glad you liked the video. My understanding is that today's LCD computer monitors don't refresh the way that old CRTs did. Certainly my gadget detects no such flicker when pointed at a light spot on my monitor. It would probably pick up something if the computer were displaying an animation that switched rapidly and regularly between a very light and a very dark scene.
Yes, powered from a USB bank. Your opto isolator comment is spot on. This started when I was playing with removing the 60Hz flicker from an LED string by adding first a bridge rectifier and then a filter cap. This, unsurprisingly, works. But I was not willing to probe it with my scope because it was not physically where I was working with the LED string and also one has to be careful probing bridge rectifier circuits because the scope probe is earth grounded. You need a differential probe (which I do not have) or to separately probe the LED plus and minus and use a math channel. I thought it would be easier to just "see" the light. But this simple approach works even better than I thought, allowing wave forms to be viewed as long as the light intensity is OK. And I have found that some LED products do strange or interesting things, like the string that flickers at 56 Hz. That's why I made the video.
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This'll be useful to correct my own led projects so they don't flash in video recordings, thanks!
It is really awesome ! one of the simplest solution I have seen but looks super effective ! Thanks for sharing it - what could happen when you point it to a computer monitor can it read its at least vertical frequency ? can you help to check if possible. Thankyou for your effort and sharing it !
I'm glad you liked the video. My understanding is that today's LCD computer monitors don't refresh the way that old CRTs did. Certainly my gadget detects no such flicker when pointed at a light spot on my monitor. It would probably pick up something if the computer were displaying an animation that switched rapidly and regularly between a very light and a very dark scene.
You made a honken' big, half-covered opto-isolator :D What method did you use for powering it portably? Just USB power from a usb bank?
Yes, powered from a USB bank. Your opto isolator comment is spot on. This started when I was playing with removing the 60Hz flicker from an LED string by adding first a bridge rectifier and then a filter cap. This, unsurprisingly, works. But I was not willing to probe it with my scope because it was not physically where I was working with the LED string and also one has to be careful probing bridge rectifier circuits because the scope probe is earth grounded. You need a differential probe (which I do not have) or to separately probe the LED plus and minus and use a math channel. I thought it would be easier to just "see" the light. But this simple approach works even better than I thought, allowing wave forms to be viewed as long as the light intensity is OK. And I have found that some LED products do strange or interesting things, like the string that flickers at 56 Hz. That's why I made the video.