Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: "Don" Newsgroups: sci.electronics.design Subject: Re: CoB LED filament analysis Date: Tue, 14 Apr 2026 12:25:57 -0000 (UTC) Organization: A noiseless patient Spider Lines: 39 Message-ID: <20260414a@crcomp.net> References: <20260411a@crcomp.net> <10ri6ll$34rpp$1@dont-email.me> <76bptkt0snst4e4ui156gh76ij4mlu4vdm@4ax.com> <10rikn2$3923u$1@dont-email.me> <1urptkdi5gicce55ke373nf5u3eofef9tb@4ax.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 14 Apr 2026 12:25:58 +0000 (UTC) Injection-Info: dont-email.me; posting-host="55386eddf2fa96580a2f4187ce6b11ea"; logging-data="123908"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/eApJpPlanMYyfmen+/G0s" Cancel-Lock: sha1:7qwb7SR/gg1PE1SrBQ7HhHmydyY= Xref: csiph.com sci.electronics.design:743017 john larkin wrote: > JM wrote: > >>>The diodes are visible next the resistors even the bond wires are faintly >>>visible in the photo. >> >>You are probably correct, but easy enough for Don to check by using a >>DC supply to check conduction with both polarities. > > Yes. Graph and don't guess. OK you guys, lots of excellent ideas! The DC idea's easiest, so it's first. Big Clive's youtube link now appears as a Footnote on the pertinent page: The webpage also includes a couple of new images where 68 VDC is applied to barely illuminate the filament's CoBs, first in one direction, and then the opposite. How do you graph such empirical data? Anyhow, as expected, seven filament CoBs illuminate regardless of DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, cross connected to conduct current through the anode of one LED, while the cathode of its coupled LED blocks current? JM, elsewhere you mention fourteen illuminated CoBs in Big Clive's video. It seems significant that fourteen CoBs are also illuminated in my filament (seven for each DC polarity). The filament also contains a small hole on one lead to denote its anode. But it's pointless because the filament conducts in either direction. Does one factory in China create CoB filaments for both AC and DC applications? So users end up with filaments filled with fourteen CoBs and an anode hole in one lead? -- 73, Don, WD7Q veritas _|_ liberabit | https://www.qsl.net/wd7q vos |