Simple question from beginner using a 15A-H-Bridge

Using Arduino Motors, Mechanics, Power and CNC
#1

I've purchased this http://www.ebay.co.uk/itm/3-36V-Dual-15A-H-Bridge-DC-Motor-Driver-30A-for-Robot-Arduino-Compatible-new-/121133655610 to control a single d.c. motor.

The output connections are self explanatory.

The input connections are :-
+5
D1 Dir1
D2 PWM1
D3 Dir2
D4 PWM2
Gnd

Presumably I can take a pwm signal straight from Arduino Uno to PWM1 and set DIR1 high or low. Then connect Arduino's 5v to +5 and gdn to gnd. I presume I can use any of the ground connections on Uno

This unit seems good value but was delivered with no info. Also the supplier is rather slow to answer questions.

The web site advises :-

Control signal:

The motor is transferred: D1 = 1 PWM = PWM
Motor Reverse: D1 = 0 D2 = PWM
Parking brake: DIR = 0 PWM = 0
Motor and power connections
Then the power of positive POWER, GND for negative one. Two motors were connected MOTOR1, MOTOR2

Any advice would be welcome.

#2

Presumably I can take a pwm signal straight from Arduino Uno to PWM1 and set DIR1 high or low. Then connect Arduino's 5v to +5 and gdn to gnd. I presume I can use any of the ground connections on Uno

Sounds reasonable.

Then the power of positive POWER, GND for negative one. Two motors were connected MOTOR1, MOTOR2

Fine, it looks like the drive is opto isolated so no need to connect the motor ground to the arduino ground.

#3

Don't expect it to handle 15A though, the PCB traces are not really up to that current level
AFAICT.

Add a fuse to the incoming supply to protect the traces from burning out perhaps?

They have kept bare metal on the high current traces which allows you to solder on
thick wire to bolster the current handling if you need the full rating I think.

#4

Thanks for the advice. The setup as described above worked just fine. I just didn't want to do anything stupid in my ignorance!
I don't expect to be using anything like the maximum current to the motor but will keep an eye on the temperature of the heat sinks.
Now to put the motor to work on a real job!

#5

Maybe i spoke to soon. After < 1 min running @ 25% speed (no load) I noticed that one of the heat sinks was quite hot, I guess maybe 90-100 oC. I see the spec for the mosfet has 170oC max. Should I be worried?

#6

Should I be worried?

Yes that 170oC is the junction temperature, there can be a lot of thermal resistance between that and the heatsink.

See:-
http://www.thebox.myzen.co.uk/Tutorial/Power.html
And the examples page off that.

#7

A small 5V or 12V fan (such as a chipset fan) can be a useful addition, quiet and
will make a big difference to the heatsink temp.

#8

You can buy/make heat sinks for the MOSFETs similar to the below.

http://www.radioshack.com/to-220-heat-sink/2761363.html#q=heat%2Bsink&start=1

#9

I tried the motor on MOTOR2 instead of MOTOR1 and the control board runs cool!
I may have damaged the MOTOR1 half of the board at some point.

#10

Hey, a total beginner here.

I'm using the same H-bridge. Just wondering how do you exactly apply PWM in this because my PWM signal from the Arduino Uno seems to be bypassed whenever I feed 5V to the 5v+ pin on the driver. I've connected common grounds and everything.

Please Help :confused: :confused:

#11

Start your own thread, this one is over four years old!
Please read the how to use this forum sticky post to find out the rules here.
Plenty of people will be willing to help you when you start your own thread.

#12

My bad Mike :sweat_smile:

#13