I broke my Motorshield

Adafruit Ethernet, Motor, Proto, Wave, Datalogger, GPS Shields - etc!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
daedelus
 
Posts: 3
Joined: Sun Jul 17, 2011 4:34 pm

I broke my Motorshield

Post by daedelus »

I put too high a voltage 31v to the EXT PWR input and something smoked. I was trying to run a stepper that needed 24v but I screwed up and used the 31v instead.

Any suggestions?

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: I broke my Motorshield

Post by adafruit_support_bill »

Do you know what 'smoked'. Are there any obvious signs of damage? What are the symptoms that indicate somethind smoked?

User avatar
daedelus
 
Posts: 3
Joined: Sun Jul 17, 2011 4:34 pm

Re: I broke my Motorshield

Post by daedelus »

Didn't actually see any smoke or damage, but definitely heard a pop and can smell that distinctive odor from burnt electronics. The LED no longer lights. I did not have the PWR jumper on.

The Duemilanove seems fine.

I just noticed, if I plug in the 9v source and put the PWR jumper on. then the LED does light. Maybe I don't have a problem after all. :-O

IC1 is getting very hot now. Think I need another L392D.

User avatar
adafruit_support_bill
 
Posts: 88093
Joined: Sat Feb 07, 2009 10:11 am

Re: I broke my Motorshield

Post by adafruit_support_bill »

The shield itself is designed to handle up to 36 volts. But if you over-volt your motors, you will also increase the current through the L293Ds. If the current goes much over 600mA for any significant amount of time, you run the risk of smoking the H-bridge. The ones I've blown usually show obvious signs of damage (typically a chunk blown off the top of the chip). But if you smelled something burning, there was some damage somewhere.

It's a common occurrence when experimenting with motors. That's why we ship the kit with sockets!

User avatar
daedelus
 
Posts: 3
Joined: Sun Jul 17, 2011 4:34 pm

Re: I broke my Motorshield

Post by daedelus »

I did use the sockets, good call. When I powered up the rig, there was a quick noise from the motor and the pop, all less than two seconds before it stopped and I pulled the power.

So, I'll order replacement L293Ds and some spares. Probably do the piggy back trick with them too.

BTW, I'm using a 5 wire stepper from an HP printer scanner p# M35SP-9 that lists a working voltage of 24v and rated current of 517mA, if anyone has any experience or suggestions.

Also, any hints as to where to get the L293Ds or the SN754410?

Locked
Please be positive and constructive with your questions and comments.

Return to “Arduino Shields from Adafruit”