# how do you test a flashing LED source?



## danz409 (Dec 20, 2018)

so i'm working on a project that involves a LED that flashes and i need to test the output of various combinations of LEDs. however the product is designed to both illuminate and get attention. so it flashes. i have a "white box" setup with a basic lumens tester i bought off amazon and it seems to work rather well for just a simple LED flashlight. however when i try putting a light that flashes in the chamber i can't get a good reading. with my fluke DMM i at least have a function to get average over time and min/max mode. however the flux meter isn't quite as nice. sample rate is trash and no min/max/average mode to speak of. does anyone have any suggestions before i bypass the "clock" on this thing?


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## desert.snake (Mar 26, 2019)

You can connect an oscilloscope and see what kind of current is going through LED and see LED specifications to find out how many lumens with this current. Second way - you can find out how many lux are you if you start the LED without blinking, but with the same current as the oscilloscope shows when blinking. In this case, the light meter will have time to fix the values. The biggest problem is finding an free oscilloscope.


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## GregP507 (Jun 15, 2019)

Oscilloscope kits are fairly cheap and available online. Some multimeters have an oscilloscope function as well.


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## Sam Bryson (Sep 17, 2019)

There is an easy way to fix this issue. Turn it on and aim it at the *light source* in question while looking at the image captured on the screen. If you see a series of dark and *light* bands traveling slowly across the screen, then your *light* has flicker. There are two main types of *flickering*[FONT=arial, sans-serif] with lights – ... The photo metric flicker found in electric [/FONT]*light sources* is ... Drivers, LED load and *test* equipment should be.


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