Custom Planar Transformer - Page 1
Forum section: electronics / projects

author: EEVblog
author_rank: Unknown
timestamp: February 04, 2019, 03:42:52 am
content: Looks sexy

author: ali_asadzadeh
author_rank: Super Contributor
timestamp: February 04, 2019, 06:01:39 am
content: The size info and PCB layers if could be counted would be nice to be shared

author: jbb
author_rank: Super Contributor
timestamp: February 04, 2019, 07:00:16 am
content: PhwoarMight this be related to an ongoing project?

author: EEVblog
author_rank: Unknown
timestamp: February 04, 2019, 07:36:46 am
content: Quote from: jbb on February 04, 2019, 07:00:16 amIt might.

author: mvs
author_rank: Frequent Contributor
timestamp: February 04, 2019, 11:16:56 am
content: Quote from: EEVblog on February 04, 2019, 03:42:52 amYes, but is it more useful for your application, then a conventional one?

author: EEVblog
author_rank: Unknown
timestamp: February 04, 2019, 11:23:04 am
content: Quote from: mvs on February 04, 2019, 11:16:56 amThat's the plan.

author: LapTop006
author_rank: Unknown
timestamp: February 04, 2019, 12:08:11 pm
content: Looks like you'd still need a hole in the board to mount it, or you'd need to add pins.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 04, 2019, 03:16:44 pm
content: Excuse me for not being as excited -- they're pretty standard fare these days. That said, where's it from -- off-the-shelf component, custom from a supplier, or fully in-house custom (made yourself)?I used my first ones back in... 2012 or so? Haven't had a need since. An application almost came up recently, but nah...Tim

author: jbb
author_rank: Super Contributor
timestamp: February 04, 2019, 07:14:55 pm
content: Yeah, that is the thing. The wire wound ones have better copper fill factor.I guess we’ll find out when a video happens. My guess is that someone needed a skinny transformer to fit into an envelope.

author: floobydust
author_rank: Super Contributor
timestamp: February 04, 2019, 08:25:30 pm
content: I've only encountered PCB planar transformers in this Rosemount 5300 guided-wave radar liquid level sensor. I believe one is for power and another for data. The HV isolation is to meet hazloc requirements for an IS barrier to the probe which may be in a fuel tank.It's just a split ferrite core clipped around a PCB for the windings.Trouble is the ferrite is conductive and the core needs to be glued in place.edit: note the extra plastic insulators between pcb top/bottom layer and the ferrite core.

author: Benta
author_rank: Super Contributor
timestamp: February 04, 2019, 09:01:13 pm
content: "Trouble is the ferrite is conductive and the core needs to be glued in place."Ferrite isnotconductive. Iron core is.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 04, 2019, 09:36:05 pm
content: Ferrite IS conductive; RTFDS.Specifically, MnZn ferrite is a semiconductor, with modest resistivity in the usual form. You'll measure on the order of 10s of kohms when you probe across a core.NiZn ferrite is also a semiconductor, but typically much higher resistivity (hmm, I'm not sure offhand if this is a bandgap thing, or a doping thing, or an impurities thing), in the megs range.Tim

author: coppercone2
author_rank: Super Contributor
timestamp: February 04, 2019, 11:23:14 pm
content: you can fail a leakage/emi test with inductor magnet wire shorted to core shorted to chassis if its chassis mount

author: jancumps
author_rank: Unknown
timestamp: March 08, 2019, 08:12:58 pm
content: Here is a design for a GaN buck converter: