How much external volt to power 12 pcs. of SG90 9g servo motors?

Other Hardware Motors, Mechanics, Power and CNC
1

Hello, if I have a Arduino Mega sensor shield on top of my arduino mega, and i want to power 12 pcs. sg90 9g servo motors, how much extra power do I then need to put in the little external power box where the screws are? Please help me :smiley:

2

Never used such a shield: are you sure it's for providing power to servos which by definition are not sensors.

But assuming that's ok... according to this, those servos draw about 750mA each. In a recent thread another poster said he measured 1.2A each with one of those servos.

So do the maths.... 12 x 0.75 or 12 x 1.2 is the current you need.

3

Hello, thanks you for your help. I live in Denmark, and in Denmark we dont have "current" we only have Volts and Amps, so could you please translate how much Volts and Amps i need for the external power supply to the shield?

Here is the shield that i bought: https://www.aliexpress.com/snapshot/0.html?spm=a2g0s.9042647.0.0.3mSsPO&orderId=86531087727455&productId=32556563187

  • Thanks for the help, karma added.
    Adam
4

in Denmark we dont have "current" we only have Volts and Amp

Unless Denmark is in a different universe, you do have current. Current is measured in Amperes.

You supply the voltage required by the servos, 5V. The power supply must be able to supply enough current at that voltage for all servos that are moving at once. We usually recommend 1 Ampere per moving servo.

If all 12 servos move at once, the power supply should be 5V and provide at least 12 Amperes.

5

Even if you didn't realise current comes in Amps, surely you saw the "A" in mA? But nvm, jremington has explained :wink: And just noticed I left the link off my first reply which says those servos are 750mA; added it now. I asked the poster who measured 1.2Awith those servos to try a different meter, since 1.2A does seem excessive. But you should definitely budget 1A each.

That link wants me to sign in; I don't have creds for that site.

6

Okay, thanks, I know im really n00by but my Mega 2560 board have 5v, so if i just attach the shield on the Mega, do that gonna apply 5v? or do I need 5 more volt in the external power thing where the screws are?

And do anyone know where i can buy a adapter with that amount of current? :slight_smile:

Thanks for the hlep :smiley:
Best regards, Adam.

7

adytech13:
if i just attach the shield on the Mega,

I said above I can't access that link, so have no idea of how the shield works.

8

How about now? https://www.aliexpress.com/item/Free-shipping-Electronics-Integrated-Circuit-for-arduino-MEGA-Sensor-Shield-V1-0-V2-0-Dedicated-Expansion/32313726680.html?spm=2114.search0104.3.26.q8xZim&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10065_10151_10068_10344_10342_10343_10340_10341_10304_10307_10137_10060_10155_10154_10056_10055_10054_5470020_10059_100031_10099_5460020_10338_10339_10103_10102_440_10052_10053_10142_10107_10050_10051_10325_5380020_10171_10326_10084_10083_5370020_10080_10082_10081_10110_10111_10112_10113_10114_143_10312_10313_10314_10078_10079_10073,searchweb201603_14,ppcSwitch_5&btsid=91a747a1-53ad-46ed-9641-950654288109&algo_expid=aabfe0aa-fbcd-4187-aaf0-4acd68476510-3&algo_pvid=aabfe0aa-fbcd-4187-aaf0-4acd68476510

9

Yeah I can see it now, but it doesn't say much. Looks like you put power in at the blue screws yes, but I see there's a jumper just behind that blue block . It looks like it says "PWR" but can only see "PW". That jumper may have something to do with powering the Mega from the blue screws, I don't know. You'll need to find some documentation.

I'm not going to speculate about how to run 12A worth of servos off a shield that calls itself a "sensor" shield: see first line of reply #1 :wink: