Power adapter for Arduino Uno robot arm

Other Hardware Motors, Mechanics, Power and CNC
1

arm
arm1920×1226 261 KB

I'm trying to make an arduino uno robot arm for coding practice. It has worked in the past (I think using the circuit board as the servo power source which I read was bad but live and learn) but through modifications it has stopped working and I want to build it the right way with a separate power source for the servos. I decided to try this power adapter. I've read on other posts that each servo should have around .5A available and that having 6V will mostly just improve speed & torque and won't damage the servos (I've also tried 4.5V for this). I figured I could use this adapter to test things with 1 or 2 servos at a time but it won't work with any.

When I build the arduino uno introductory servo circuit which uses the circuit board as the power source and an example code, everything works. I measured the voltage and current when it's working with 1 servo powered (all others shown in the picture are disconnected) and the voltage stays around 5V and the current changes from 70mA to a peak of 500mA. My dad, a long-term electrician, told me things only pull the current that they need, which I've also read online. But when I change the servo's power source from the circuit board to the adapter, the voltage stays at around 6V but the current stays at a consistent 530mA.

Can anyone please tell me why the servo is drawing this constantly high current when it's powered by the adapter and any other mistakes I might be making which are causing the servo to not move how I want it to? Like I said, my goal through all this is to find a simple, plug-in power source for the servos. I've seen variable DC power supplies on Amazon for like $50 and I've also worked with those before in school labs but I'd rather not have to spend that much just for this. We also have other random adapters around the house and I know I could order one for fairly cheap but I don't want to run into the same issue after buying one. All advice is appreciated, sorry for any inexperienced ignorance, lol. Thank you

2

When I say the motors don't work, I mean the motor makes a noise as if it's working but it's just vibration and it doesn't rotate. I experimented by adding in the rest of the 3 servos I'll be using and the current went up but the servo sounds seem to vary slightly more. When I used 4 servos instead of 1, the vibration sound became louder during the time it should be moving, and quieter when it shouldn't have been whereas when I had 1 servo it seemed pretty constant. Not sure if this means they were handling the divided up current better together even though it also went up. Just figured I'd toss that in

3

Servos always need power to hold their position as well as move to new positions.

4

That makes sense, but I definitely worded the question poorly. I'm wondering why it draws the 500mA current constantly with the new power supply whereas the current fluctuates when the circuit board powers it. My guess is that that's part of the problem of why the servo doesn't move with the new power supply.

5

Are you serious? The regulator on your circuit board is likely overloaded/heating and that is causing the changes. Please provide a schematic of your project and whatever the circuit board happens to be.

6

I fixed it lol. Just needed to connect the grounds on both boards. Wasn't anything serious but thank you

7

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.