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From: "Don" <g@crcomp.net>
Newsgroups: sci.electronics.design
Subject: Re: CoB LED filament analysis
Date: Fri, 24 Apr 2026 20:15:46 -0000 (UTC)
Organization: A noiseless patient Spider
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Don wrote:

<snip>

> There's no need to goof with a shunt resistor when an accurate current
> probe measurement is already available:
>
>     <https://crcomp.net/ledfilament/curveprobe.png>
>
> It shows you everything you need to do your own math. Show me your
> math and I'll included on my webpage, with your permission.
>
> Hint for people who still don't see the light (so to speak): Bob Pease
> said, "My favorite programming language is solder." On a related note,
> Pease passionately hated one piece in particular, amid the equipment
> found in an electronic lab.

Game over. Lessons learned:

1. Pease hated solderless breadboards for a good reason: they introduce
   stray capacitance. After the solderless breadboard is removed the
   filament's current curve reverts to its true form with voltage and
   current in phase.
   
2. Filaments behave better when you use a brand new bulb in place of a
   filament from a broken bulb.
   
3. Don't conjure up spirits resting in peace.

The webpage will be updated with: corrected images of the current curve,
photos of a new bulb without a breadboard, an internal schematic of the
CoB LED, piglet's diagram, and a lab report.

Calculating the capacitance from the original current curve with a 
breadboard in situ would be fun. But the stray capacitance detour won't
be mentioned on the webpage to keep things simple.

This has been an entertaining side-show for me. I hope you guys had fun 
too. It beats doom-scrolling.

Danke,

--
73, Don, WD7Q                                             veritas    _|_
                                                          liberabit   |
https://www.qsl.net/wd7q                                  vos         |