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Electronics => Electronics => Topic started by: silo_xtreme on July 11, 2009, 10:11:07 AM

Title: Chaning Directions on L298N / H-bridge
Post by: silo_xtreme on July 11, 2009, 10:11:07 AM

Hey All,

I blew up an L298N today.  I was wondering - is it always necessary to stop the motor before changing the direction?

I went from CW to CCW then to STOP and my L298N.

I'm thinking some how this might have caused a stall condition....  ???

I'm just looking for your thoughts,

Thanks!

Mike

Title: Re: Chaning Directions on L298N / H-bridge
Post by: jamort on July 11, 2009, 11:02:40 AM

simple physics the motos HAS to top to hange directions rather you tell it too or not :P

Title: Re: Chaning Directions on L298N / H-bridge
Post by: SmAsH on July 11, 2009, 03:30:25 PM

it may be the motor drew too much current from the l298...
whats the motors stall current?

Quote from: jamort on July 11, 2009, 11:02:40 AM

simple physics the motos HAS to top to hange directions rather you tell it too or not :P

you don't know how much trouble i had reading that XD

Title: Re: Chaning Directions on L298N / H-bridge
Post by: silo_xtreme on July 11, 2009, 03:33:21 PM

The motor stall current is about 6.5A.

I have 2 L298A together to sink the max A.

Did not stopping the motor before switching directions cause the stall?  ???

Title: Re: Chaning Directions on L298N / H-bridge
Post by: jamort on July 12, 2009, 04:05:49 AM

simple physics the motos HAS to stop to change directions rather you tell it too or not... woops lol

Title: Re: Chaning Directions on L298N / H-bridge
Post by: SmAsH on July 12, 2009, 05:20:26 AM

Quote from: silo_xtreme on July 11, 2009, 03:33:21 PM

The motor stall current is about 6.5A.

I have 2 L298A together to sink the max A.

are you using both l298's to run one motor? like using all four output pins from each chip in parallel?
the datasheet says an l298 can handle 3A non-repetitive, 2.5A repetitive (80% on-20% off) and 2A continuous.
if you were only using one channel from each l298 then it could only supply 6A and its possible you drew too much current. if you were using both channels on each l298 then you would have 12A peak, so it would be fine.

Quote from: jamort on July 12, 2009, 04:05:49 AM

simple physics the motos HAS to stop to change directions rather you tell it too or not... woops lol

did you mean whether? the current would be less if you stopped it first before switching directions...
if your motor is going full ball one direction, the power to stop it and start it going in the other direction will be massive and maybe give some back emf.