[sdiy] PCB Transformers

[brianw]

On Jan 19, 2023, at 1:47 PM, cheater cheater wrote:
> On Thu, Jan 19, 2023 at 1:13 PM Roman Sowa <modular at go2.pl> wrote:
>> 
>> My first reaction was "what an idiotic crazy idea with no purpose". But
>> then again, since we get internal layers for free (JLC making 8-layer
>> PCB for $2 now) it's no brainer to leave one or two layers for the
>> heater
> 
> Has anyone ever tried putting transformers in pcb layers? I guess it
> wouldn't be audio frequencies (due to size), but it might still be
> fun. How about: Audio -> RF -> tiny transformer -> RF -> Audio?

This example wasn't a transformer, but Ensoniq used PCB traces to create inductive coils under every key for their polyphonic aftertouch circuits. So, not a whole transformer, but half of one.

Brian