I was under the impression that the cap was for smoothing out the power to the Arduino (actually a nodemcu esp8266 module in this case). Apparently these things can act strangely without a good clean power source.
On Wed, Nov 1, 2017 at 11:49 AM, <ch...@wbmfg.com> wrote: > Your diode needs to be larger than the total current the combination will > draw at peak. The cap could be for power supply filtering or emi or ? Not > really sure. > > You could use just a 2.7 volt zener diode (reverse biased) inserted in > series with the Arduino to knock off 2.7 volts off of the 6 volts. > > *From:* Jason McKemie > *Sent:* Wednesday, November 1, 2017 10:27 AM > *To:* af@afmug.com > *Subject:* [AFMUG] OT: Electronics Question > > I'm rigging up an Arduino controlled blind setup and trying to configure > the power supply. The installation will have an Arduino (3.3v) and a servo > that will operate at around 6v. I was going to supply the whole thing with > 6v and use a step-down converter on the Arduino. Someone recommended using > a diode on the + input, and a cap across the inputs to the step down - how > would I go about sizing these appropriately? >