Questions tagged [current]

Flow of electric charge - typically movement of charge carriers, such as electrons. Measured in amperes (A).

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31
votes
4answers
92k views

What is stall current and free current of motors?

What are the stall and free currents of an electric motor? For example, this Vex motor lists its stall and free currents at the bottom of the page. I think I understand the general idea, but a ...
5
votes
2answers
3k views

Arduino Vin Current Limit

I've found that Arduino (Duemilanove) has a current limit of 40mA per pin. Does this include the Vin pin? Or does the Vin pin have some sort of work around in place on the board to allow for higher ...
5
votes
2answers
17k views

How to tell a stepper motor's position, or detect slippage

I am creating a CNC machine on a budget, using old motors out of printers/scanners/etc. I am limited to about 650mA for the whole system, so my fear is that when the cutting bit touches the material,...
2
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4answers
184 views

How to deal with current spikes due to fast direction-switching motor commands?

I'm trying to build a self-balancing two-wheeled segway-like robot. I'm currently using two 12v DC motors that draw approximately 600milliamps of current each. I've noticed that when my robot tries ...
2
votes
2answers
313 views

What are some ways to estimate torque/load on a robotic arm joint

My main problem is measuring joint torque/load economically. There are ways to detect the electric current drawn which is proportional to the torque. Since my motor is a BLDC motor, there will be a ...
2
votes
1answer
176 views

Power switch standards and suitability for purpose

I scavenged a 4 terminal power switch (Legion EPS 21) from some electronic device (don't remember what it was) and it has the following markings on it: Legion EPS21 10A 250VAC TV-5 8A/128A 250V &...
2
votes
1answer
120 views

Comparison of the efficiency of DC motor current limiting / control methods?

I am using the wheels and motors of an RC toy car as a simple robotics platform. The car has 2 motors, one drives the back wheels, the other steers the front wheels. The steering motor is stalled by ...
1
vote
3answers
629 views

Can't Read current on Pololu Dual MC33926 Motor Driver Shield for Arduino

I purchased a Pololu Dual MC33926 Motor Driver Shield for Arduino, and for some reason I cannot read current from the motor controller. On the Serial.println() it just prints weird data (garbage), and ...
1
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3answers
401 views

Can too much input current destroy my motor driver?

I have a 18 V rated driver I'm using to drive two 12 V DC gear motors using my Arduino. I bought a new battery pack which is rated 3300 mAh 25C, 11.1V making the total current input 82.5 A. My driver ...
1
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2answers
664 views

Servo motor power consumption issue

I am using servo motor model no. MG995 with Arduino. I don't know the current it consumes while powered on and while lifting a 10 kg of weight. I am currently using a 5 V, 1 A power supply with one ...
1
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1answer
336 views

Brushless DC motor problems at high velocities

For a project we use a brushless DC (BLDC) motor. Everything works fine until we tried to reach high velocities. I will first explain my setup, and than explain our problems using some graphs. 1.0 ...
1
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2answers
983 views

How can I reduce a motor's maximum current draw?

I have a motor with a stall current of up to 36A. I also have a motor controller which has a peak current rating of 30A. Is there any way I could reduce the stall current or otherwise protect the ...
1
vote
2answers
183 views

Motor driver selection

I am building a 2 wheel robot to carry 7KG of load. I used this link to get the torque required for each motor which is 11Kg-cm. So I choose 2 of these motor which has 36Kg-cm(2x more) torque. I ...
1
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1answer
42 views

Powering servos for quadruped spiderbot using arduino uno [closed]

I am using 12 towerpro SG90 servos. What battery should I use for powering 12 servos for my arduino uno? Can i use the 12v battery, plug it in to 12v dc jack of arduino and tap the 5v output of ...
1
vote
1answer
53 views

Electronic speed controllers and total current draw

Do we have to take Electronic Speed Controllers (ESC) into account when calculating the total current draw of the system? As far as I can understand, the motor and ESC are connected in series, so we ...
0
votes
1answer
36 views

How can a motor be run at higher voltage for longer?

A 12V windshield wiper motor to run at 24V for more speed but near-equal driving force. Testing with a variable DC supply between 21.6V & 26.4V showed the current maxes at 3.72 - 3.90A, as ...
0
votes
2answers
197 views

what is the difference between a voltage source and current source? [closed]

I know,this question is irrelevant.But,while working suddenly this question came through my head..my point is there should not be any difference between a voltage source and a current source.cause,...
0
votes
1answer
819 views

Arduino with two Linear Actuators, two ACS714 Current Sensors, and an L298N Motor Driver setup

I am using the L298N motor driver to drive two HAD1 linear actuators (12V each and a no-load drive current of ~950mA each) Linear Actuator: http://www.alibaba.com/showroom/mini-linear-actuator-had1....
0
votes
1answer
372 views

DC gearmotor stall current and battery capacity

I'm working on a self-balancing robot project and am in the process of motor sizing. I've read that with self-balancing robots the motors need to switch direction quickly, which can cause them to ...
-1
votes
1answer
101 views

How to test how much current 9 servos can draw at a time [closed]

Plus how should I use a multimeter to test it. P. S. Really sorry for a noon question