Re: Nextion with KA78T05

Lawrence Galea
 

When dropping down voltage I always use more than one regulator in series to split the dissipation.
E.g. 7809 or 7808 from the nominal 12V then to the 7805 and bolt them to the aluminium case or to a heat sink with thermal compound.
They are cheap enough not to bankrupt you.
Take care when buying from Ali etc
Regards
Lawrence

On Tue, Sep 17, 2019 at 11:50 PM Razvan (M0HZH) <razvanfatu@...> wrote:
Maximum current draw for the 5" Nextion (backlight @ 100%) is 410mA 
Arduino Nano ~20mA
Si5351 (all outputs enabled) ~22mA

Assuming 13.8V input, there's over 4W of thermal power to be dissipated. As Allison already explained, whatever IC you'll use it'll need a heatsink.

Also, try to keep the heat away from the Si5351 oscillator crystal as it would generate frequency drift.

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