Connecting HBridge to an external 12v source

Drive a 4-wire bipolar stepper motor or a pair of DC motors from your Arduino. [Product page]
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fynx
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Joined: Thu Nov 28, 2013 9:51 am

Connecting HBridge to an external 12v source

Post by fynx » Thu Nov 28, 2013 9:58 am

Hi,

I just bought the Freetronics H bridge. I've been struggling to run the motors off an external power source (12v) and it doesn't seem to run.

What i did,

1. just hook 1 dc motor to channel A (pin 1 & 2 ),
2. then put a jumper on the Bridge Vin,
3. then plug to usb cable to my arduino,
4. upload the code
5. unplug the usb cable
6. hook the 12v external power source to the Hbridge
7. plug the usb calbe to the arduino.
8. at this point, nothing is happening to the motor.

But if I:
1. Unplug the 12v external power source
2. unplug the usb cable from the arduino
3. plug the 9v battery jack to the arduino
4. after a few seconds, i see the activity on the dc motor.

Anyone who can help me with my problem? What am i doing wrong here?

Cheers!

cef
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Re: Connecting HBridge to an external 12v source

Post by cef » Thu Nov 28, 2013 12:26 pm

Thoughts:

Have you tried connecting the 9V battery directly to the power input on the HBridge shield?

Have you tried hooking the 12V external supply to the Arduino DC socket?

Note: Make sure you get the polarity of the power input to the HBridge shield the correct way around.

fynx
Posts: 3
Joined: Thu Nov 28, 2013 9:51 am

Re: Connecting HBridge to an external 12v source

Post by fynx » Thu Nov 28, 2013 7:34 pm

cef wrote: Have you tried connecting the 9V battery directly to the power input on the HBridge shield?

Have you tried hooking the 12V external supply to the Arduino DC socket?
Have you tried connecting the 9V battery directly to the power input on the HBridge shield?
=> Nope, because i need the 12v supply.

Have you tried hooking the 12V external supply to the Arduino DC socket?
=> Nope, because I'm afraid it will burn my arduino?

andrew
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Re: Connecting HBridge to an external 12v source

Post by andrew » Thu Nov 28, 2013 9:34 pm

fynx wrote:Hi,

I just bought the Freetronics H bridge. I've been struggling to run the motors off an external power source (12v) and it doesn't seem to run.

What i did,

1. just hook 1 dc motor to channel A (pin 1 & 2 ),
2. then put a jumper on the Bridge Vin,
3. then plug to usb cable to my arduino,
4. upload the code
5. unplug the usb cable
6. hook the 12v external power source to the Hbridge
7. plug the usb calbe to the arduino.
8. at this point, nothing is happening to the motor.

But if I:
1. Unplug the 12v external power source
2. unplug the usb cable from the arduino
3. plug the 9v battery jack to the arduino
4. after a few seconds, i see the activity on the dc motor.

Anyone who can help me with my problem? What am i doing wrong here?

Cheers!
Hello fynx
Your connections are fine. Can you test the 12V supply with a multimeter - and check you have the polarity correct when connecting to the HBRIDGE?

As you have the Vin jumper on the shield, this connects the DC socket power to the HBRIDGE as well as the Arduno - so if the motor turns when the DC socket power is applied to the Arduino it would seem your 12V supply isn't working or the connections are the wrong way around.

Let me know how you go
john

fynx
Posts: 3
Joined: Thu Nov 28, 2013 9:51 am

Re: Connecting HBridge to an external 12v source

Post by fynx » Fri Nov 29, 2013 11:49 am

Thanks for the reply. Yes I did test the batteries and checked the polarities very carefully before plugging it to my arduino. I don't want my arduino to burn or some sort...

When I check the multimeter the reading is about 13v.

Question 1: I should be able to power the entire thing using the external battery right (arduino + 2 servo motors)
Question 2: Does it have to use the same exact motor when plugging to the freetronics hbridge?

andrew
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Re: Connecting HBridge to an external 12v source

Post by andrew » Sat Nov 30, 2013 12:05 am

fynx wrote:Thanks for the reply. Yes I did test the batteries and checked the polarities very carefully before plugging it to my arduino. I don't want my arduino to burn or some sort...

When I check the multimeter the reading is about 13v.

Question 1: I should be able to power the entire thing using the external battery right (arduino + 2 servo motors)
Question 2: Does it have to use the same exact motor when plugging to the freetronics hbridge?
Q1 - yes
Q2 - the DC motor can be anything that doesn't draw more than 2A of current, and operates on between 8 and 40V DC.

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