Hi, I am new to arduino and its coding. I am attempting to do a project where I am need DC motor to run and I can vary the speed. I am using an arduino mega 256 with l298n bridge. The motor I use has following specs.
Voltage: 12 volt DC
No load RPM: 5,310 (+/- 10%)
Free Current: 2.7 amps
Maximum Power: 337 Watts (at 2655 rpm, 172 oz-in, and 68 amps)
Stall Torque: 2.42 N-m, or 343.4 oz-in
Stall Current: 133 amps
I use 12 volt battery I bought from amazon.
When I connect the motor directly to the battery it runs with high rpm, but when I connect it with l298n, even with speed of 255 from the arduino the motor runs very slow and then stalls and ultimately stops. It just keeps winning. I tried changing the speed through arduino, only the whining sound change, speed doesnt. My question is what other parameter should I need to control/change to increase the motor speed.
One KEY thing missing here, how's overything connected? Where's the schematic?
BTW, the l298n is only able to drive 2A per channel. You can parallel both channels to get 4A but you have to do it right. So that motor is just WAYYYYYYYYYYYYY to heavy for that poor driver You will need a pretty beefy motor driver to handle the 133A stall current!
I am need DC motor to run and I can vary the speed.
You didn't say if you need to reverse it, or just run it in one direction.
If you only want to run it in one direction, a high current logic-level N-channel MOSFET is far better than an L298 driver. (You might need a couple in parallel.)
I need two DC motors to run in opposite directions. But they don't need to reverse their direction, each has to continue running in particular direction. I need to vary the speed of each independently though, meaning the speed can be different in each motor and they will run in reverse direction.
Nothing beats a real schematic. Next time, just draw one and post a photo
If you don't need reverse you don't need a H-bridge driver. But still, 133A is MASSIVE. Even for some mosfets... Be prepared for a beefy heatsink Not really a beginners electronic project...
The high current logic-level N-channel MOSFET that you suggested, do I connect it similarly to the arduino mega 256, and is the arduino compatible with it. Could you please help me out a bit more pointing out where I can read about its use and how I can connect it.
Chatterjeesidd:
The high current logic-level N-channel MOSFET that you suggested, do I connect it similarly to the arduino mega 256, and is the arduino compatible with it. Could you please help me out a bit more pointing out where I can read about its use and how I can connect it.
Here's the basic configuration for a single MOSFET driving a DC motor:-
You'd possibly need a couple of MOSFETs in parallel, depending on their ratings, and almost certainly need a heatsink.
The diodes would need to be able to handle a reasonable amount of current, too.
Also, the MOSFET(s) would need to be "logic-level" to turn on fully with the 5V from the Arduino. You might even need a MOSFET driver considering the amount of current that you'd be switching.
I can't suggest any MOSFET or diode part numbers off the top of my head.
As septillion says, "Not really a beginners electronic project..."
Forget making your own motor driver. Beginners simply cannot make a circuit that can safely handle > 100 amps startup current. Also, a MOSFET that can control that amount of current cannot be directly driven by an Arduino.
Get an RC car Electronic Speed Control (ESC) instead, for example, this one. The Arduino can control the motor speed as if it were an RC servo.
jremington:
Get an RC car Electronic Speed Control (ESC) instead, for example, this one. The Arduino can control the motor speed as if it were an RC servo.
Please help an eccentric old man understand your project. How much load will be on the motor when it starts to turn? How long will the motor run with the load? Will the load be dynamically balanced so there is no vibration? I ask the last because the motor is mounted with two quite small screws.
Also be SURE to make a key to fit the shaft and load and use two set screws to lock the load and hold the key in place. You are dealing with a lot of torque.
It also looks like the motor must be mounted in a metal housing for heat sinking.
You will need a pretty beefy motor driver to handle the 133A stall current!
Off by a factor of 35...
