Body
Can you down load a PDF maker and use that ?thats permanent .
On Tuesday, July 2, 2019, [email protected] [EVGRAY] <
[email protected]> wrote:
>
>
> Hi Ron,
>
> You're right. The attachments don't show up in the group. They appear
> attached to emails from the group. The one I sent also doesn't appear in
> the attachments area (https://groups.yahoo.com/neo/
> groups/EVGRAY/attachments). . Clicking 'Attachments' above show the
> attachments containing zero files in the last eight cases. Perhaps there is
> no more space left for attachments. It is only possible to delete your own
> attachments. Perhaps this is a job for Kone to look into?
>
> The artwork (PCB layout)
>
> The capacitors should be fast ones meaning low equivalent series
> resistance (ESR). A good choice would be ceramic capacitors. They're not
> stable in capacitance value which doesn't matter for decoupling purposes.
> The capacitance could be 100nF or more. The speed is what matters (low ESR)
> as they only have to hold the voltage for brief moments. I.e. delivering
> the power during transients until the wave of energy reaches the capacitor
> and connected consumer from the voltage supply.
>
> The tracks from the voltage supply first go to the capacitor and then fans
> out from here to avoid voltage drops along critical tracks. If looking at
> U1 leg 1 this has the star connection. It would be even better if this was
> at the terminal of C3 before entering the MOSFET driver U2. It would be
> preferable for C3 to be able to deliver enough power to charge C6 without
> too much voltage drop. Thus C3 should be of at least the same capacitance
> as C6. It also depends on the diode to be able to deliver that current. The
> also holds for the two other capacitors C2 and C4.
>
> For highest performance a ground plane is placed on the opposite side of
> the tracks. This makes the tracks behave more like transmission lines of
> the same impedance which minimizes reflections each time the impedance
> changes.
>
> I don't know the voltage and current or even if high switching frequency
> is needed. Just be sure to have proper creeping distances for the voltages
> used and wide enough tracks for the currents used. Also if the MOSFETs used
> have high gate capacitance and fast switching is needed then the MOSFET
> drivers have to be able to deliver high current during charging and
> discharging of the gate capacitance. Capacitance at high frequency is a
> good conductor like a short. The output tracks looks narrow compared to the
> power tracks.
>
> Regards
> Ole
>
>
>
>
> ---In [email protected], <iron1of1@...> wrote :
>
> I don't see any photo.
>
> Ron
>
>
> ---In [email protected], <iron1of1@...> wrote :
>
> Hi Ole,
>
> I have reworked the board... better?
>
> Ron
>
>
>