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Topic: Servo is bucking in the target position (Read 647 times) previous topic - next topic

DonPedro

Hello everyone,

I am using an Arduino UNO. The Trouble is, that the servo I use (Modelcraft MC-140, Standard) is bucking in the target positions.
The uno is hooked up to a 9 V power supply. (switching power suppy)
For the servo I have bought a 5V (300mA) power supply (Stabilazed smoothed Output)
I have connected to minus pole from the 5V supply  with the 5 V pole of the Arduino. ( I read this before in this forum)

Does anybody have an idea what could help in this case?
Thank you very much in advance and friendly greetings from Germany.

Peter



terryking228

Hi,

Show us (hand drawing OK) how this is wired... 
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

Idahowalker

#2
Feb 09, 2019, 11:43 pm Last Edit: Feb 09, 2019, 11:44 pm by Idahowalker
I have connected to minus pole from the 5V supply  with the 5 V pole of the Arduino. ( I read this before in this forum)

What you wrote indicates that you have connected the ground of the servo supply to the +5V of the Arduno? If this is the case remove that connection and replace it with a connection from the ground of the Arduino to the ground of the servo supply.

DonPedro

Hello Terry,
here is the wiring. Any help would be greatly appreciated!
Vielen Dank imm Voraus für Eure Hilfe
Peter

slipstick

The wiring looks o.k. if you're sure your IR receiver and LCD can take 9V. I can't tell as you've given no details of them.

But 5V 300mA is nowhere near enough for a standard size servo if that's what a MC-140 is (Google can't find it - did you mean MC-410?).

Try a 5V power supply that can deliver at least 1A preferably more (or a battery like 4 x AA NiMH rechargeables which should work).

Steve

DonPedro

1. The Uno R3 has a 9V power input
2. I have tried now a 5V / 6V 1.5 A power supply for the servo and the Arduino. (I plugged the 5V and GND Output from the power supply in one of the 5V/GND sockets of the Arduino
3. The power supply is not equalized. The servo doesn't work at all. It is a switchable power supply. I tried it with 6V. Also no success. Unfortunately, the Display flickers shows nosense signs.

Yes, it is a MC-410.

Any idea whats going wrong here?

Thanks in Advance
Peter

vinceherman

What happens if you remove the LCD from the circuit and the code, and simply run the servo sweep tutorial?

Idahowalker

#7
Feb 12, 2019, 10:43 pm Last Edit: Feb 12, 2019, 11:03 pm by Idahowalker
For the servos, a switching power supply that has multi-volt outputs?

300mA power supply for the servos, not enough amps. The servos current draw will cause the voltage to drop, the voltage drops, the servos cut out, the servos cut out they lose position and the power supply kicks back in, when the power supply kicks back in, the servos current draw will cause the voltage to drop, the voltage drops, the servos cut out...
Add to that a switching power supply that is only on for 1/2 the time.
https://forum.sparkfun.com/viewtopic.php?t=35352

Northof49

I've had good luck running servos from old recycled computer power supplies.  For portable projects, I use lipo batteries that feed into a DC-DC converter that puts out 5v 5amps for usb and other uses.  I also have a similar DC to DC converter that delivers higher voltage, as for some servos 5 volts isn't enough.  At 5 volts they won't even move.

Idahowalker

#9
Feb 12, 2019, 11:56 pm Last Edit: Feb 12, 2019, 11:58 pm by Idahowalker
Also, are you suing a breadboard to connect this project together? Did you make the jumper wires yourself or did you get a bundle of premade wires? 22awg wire will allow 7 amps (https://www.powerstream.com/Wire_Size.htm). If you are using a breadboard and your 22awg wires are plugged into the same row, that breadboard can give, what, 300mA per row; someone correct me on this. As can be seen the math to supply several servos from a breadboard quickly shows a losing trend.

Next, those wires that came in a kit or bundle, the ones you did not make up yourself, are most likely, AL and not copper. The 7amp rating drops down, and those premade connector pins don't mate well with the breadboard. Also, if you bought the discount breadboard, drop that current rating. A lot of intermittent issues go away when you use wires connectors you made yourself with good copper clad wire, for the servos.

Hopefully, you got lots of areas to take a look at now.

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