Servo + 5V Voltage regulator issue (Current drop?)

Hi everyone,

I’ve been following an Arduino tutorial on YouTube (The one from Jeremy Blum), so the components I’ve been using are:

  • Battery (9v squared battery)
  • Servo (Micro Servo 9g - SG90)
  • 5V Regulator (L7805)

The problem is as when I wire up everything according to the example, my servo barely moves, randomly small twitches, or sometimes it doesn’t do anything at all… I have read some others forums trying to search for an answer. The main answer I’ve seen was, suggesting to use a different kind of battery (Ex: 6xAA pack). But in Jeremy’s example, he manages to do succeed while using a 9V battery? Am I using the wrong kind of voltage regulator perhaps?

Extra information:

  • Both grounds of the battery and arduino are connected
  • The 5V power of my arduino isn’t wired to my breadbord (Because we want to use the power of the battery, right?)
  • I have used to multimeter to check the voltage levels on my regulator, which states 5V on the output
  • While checking the current on the regulator, it says 0.1mA (which is not enough to make the servo move?), but sometimes it jumps around real quickly to ±0.3mA and back, which makes it twitch a little bit

So, my guess is, something is not allowing or dropping the current when it passes through the voltage regulator…

Thanks in advance,

EDIT: I have added a picture of the schematic and one of the breadbord in the attachments


A schematic of the complete thing would also have been helpful.

However I do agree that a regular 9 volt battery is not really good for sustained use as you are trying to drop almost half that voltage as wasted heat and we dont know how you have the regulator configured.

Thanks for the quick replies, guys!

@spycatcher2k : Haha, got it. But still makes me wonder why in Jeremy's video he IS able to

@ballscrewbob : My bad, I have added some images in the attachments now. Hope that clarifies more

Your picture clarifies that fact that you are not using an SG90 micro servo as you claimed. You have an SG5010 full-size servo which needs 3 or 4 times more current. So there's one difference.