Newb question regarding wiring for 12v step-up

Robotics and electronics discussion Electronics
1

Hi guys,

I’m no electronics wizard, but I have some knowledge. Anyhow, I’m currently working to power a 8-bit gimbal controller that requires 3S voltage from a RC Eye One quadcopter that has 2S power available on board. I’m hoping to use a step-up from the available 2S voltage through a U3V12F12 step-up to power it. My understanding is the current draw is maxed around 300mA so this seems do-able.

However, I also know this 8-bit controller won’t like a voltage spike. The wording in the product description is probably straight forward but I want to be sure I don’t create a short and I get the RIGHT capacitor.

I would like to know, what would be the best capacitor for this application and exactly how does it get wired in? The way I read it is that I use a 33uf or higher polarized capacitor with the (-) side connected to ground and the (+) side of the cap connected to the VIN pin. Size doesn’t matter, just weight and reliability. I don’t want to accidentally short a Lipo battery so thought I’d ask first before I do anything :).

THANKS

2

Hello.

Your proposed way of adding electrolytic (polarized) capacitor across the regulator seems fine. In general, adding a larger capacitor will result in less noise on the line.

- Jeremy

3

So, not to sound dense but when you say “across the regulator” – we are referring to connecting the polarized capacitor in the manner I stated… connecting the ground to the VIN pin with a polarized cap. Is that correct?

Thanks!

Nathan

4

Yes. If you post a wiring diagram of your proposed connections, I would be happy to take a look at it.

- Jeremy

5

Okay, sorry for my seriously terrible diagram but attached is what I am proposing.

Where I am tapping power, there’s already a capacitor but I’m guessing I need to put one right at the step-up board as well.

Thanks for the help and forgiving my newbishness :slight_smile:

worldsworstdiagram.png892×579 177 KB

6

The capacitor is in the recommended spot in your diagram. A 35V, 330uF capacitor seems like a reasonable sized capacitor for your application.

- Jeremy