[chbot] Chchrobotics Digest, Vol 141, Issue 4

[Trevor Wignall]

If the LED voltage is higher than the battery voltage so the regulator
needs to be a boost regulator, then the LED current may well be a square
wave. However if the battery voltage is higher, then the regulator needs to
be a buck regulator in which case the output (LED) current is smoothed by
the inductor and it is the input (battery) current that is the square wave.
Of course they could be using a regulator with both characteristics in
which case both are likely to be square waves!
Does anyone know what frequency the transmitters are on? If not, can
someone give us the lengths of the directional aerial's elements?
Trevor

On Thu, Jun 27, 2019 at 6:43 PM Volker Kuhlmann <list57 at top.geek.nz> wrote:

> On Wed 26 Jun 2019 20:15:14 NZST +1200, Trevor Wignall wrote:
>
> > The LEDs themselves should not be causing interference.
>
> Any square wave along a track radiates, and I'd expect that to include
> the tracks to the LED, the pins (if any), and the LED itself. Perhaps
> the regulator output is smoothed with RLC filters, but if it's a cheap
> purpose-made converter perhaps that's not the case. Why not save on some
> components. Its EMC behaviour is obviously not that good... Check with a
> scope before assuming.
>
> Volker
>
> --
> Volker Kuhlmann
> http://volker.top.geek.nz/      Please do not CC list postings to me.
>
>
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