Comparison of FLUKE 8920A Multimeter after LED Replacement - Page 1
Forum section: electronics / testgear

author: daisizhou
author_rank: Super Contributor
timestamp: May 14, 2023, 05:33:34 am
content: Hallo everyoneI replaced the LED beads used for indication in FLUKE8920a,Is it correct for me to replace it this way? I found that the brightness of the new LED is very good.I pasted the original LED lamp beads for testing

author: tooki
author_rank: Super Contributor
timestamp: May 14, 2023, 01:43:12 pm
content: Is your question simply whether it is safe to replace the old LED with a modern one?If so: it won't cause any harm (the higher Vf of the modern LED means it will get even less current than the old one did!). The only potential problem, particularly when changing to emerald green, blue, or white, is that modern LEDs can be so bright that they blind you! (In that case, you'd need to change the current limiting resistor to a higher value.) You somewhat see this in your pictures: the new LEDs are noticeably brighter than the LED display they're next to.

author: daisizhou
author_rank: Super Contributor
timestamp: May 14, 2023, 02:29:54 pm
content: Yes, the new red LEDs are very bright。I chose transparent red LED lamp beads

author: tooki
author_rank: Super Contributor
timestamp: May 14, 2023, 04:42:21 pm
content: Transparent LEDs are "brighter" because they focus the light in one direction. The downside is a much smaller viewing angle than diffused ones.But in this case, it looks like the originals were transparent, too? Does the front panel window have a diffuser for the status LEDs?P.S. FYI, calling individual LEDs "beads" is pure Chinglish.We don't say that at all, we just call them "LEDs".

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: May 14, 2023, 07:26:49 pm
content: If it was my meter, I would have made the new LED dimmer and be inline with the brightness of the segmented display from a balanced brightness perspective. But this is all cosmetic and personal preference, tune it to the way you like it.

author: daisizhou
author_rank: Super Contributor
timestamp: May 14, 2023, 09:53:01 pm
content: Quote from: tooki on May 14, 2023, 04:42:21 pmPlease take a look at the picture.I filmed the initial LED and compared it with the brand new LED I replaced.The panel is a 2.5mm thick aluminum plate，5 through-holes were opened at 5 LED bead positions,In front of the aluminum panel is a 0.5mm thick decorative panel,At the position of the LED display window and the 8-bit digital LED display tube, it is made of red transparent material

author: tooki
author_rank: Super Contributor
timestamp: May 15, 2023, 08:15:44 am
content: Quote from: daisizhou on May 14, 2023, 09:53:01 pmI looked at the pictures carefully before writing. But they're not high resolution.Quote from: daisizhou on May 14, 2023, 09:53:01 pmThat much is obvious. What's not clearly visible in the photos is whether there is adiffuseron the openings for the indicator LEDs.(Again, not beads. We do not say that for LEDs, ever.)

author: daisizhou
author_rank: Super Contributor
timestamp: May 15, 2023, 09:07:26 am
content: See the picture

author: daisizhou
author_rank: Super Contributor
timestamp: May 15, 2023, 09:14:02 am
content: window without diffuse reflector,I just see a layer of clear red acrylic plastic.So my newly purchased LED is also transparent type,it glows red