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Topic: L298N H Bridge wired wrong (Read 495 times) previous topic - next topic

skindova

Hi!
I've been working on a project in which i need to control 2 motors. Therefore, i bought a ln298n h bridge. After i wired everything and it wasn't working, i noticed i connected the wires wrong (9V from the battery connected to H-Bridge Gnd and battery Gnd to H-Bridge 12v). Even after i fixed that, the Bridge does not seem to be working (Voltage on the motor output is always 0v). Is it possible that the H-Bridge is damaged because i switched the polarity, or am i doing something else wrong?
Thanks so much!

MarkT

Yes it is very possible you have damaged it.

When you say 9V is that a small 9V battery of the sort that cannot provide enough current
to power motors?  Have you tried a decent supply instead? For 2 motors you are likely to need
several amps fom the supply.

If you are lucky the weakness of small 9V batteries in providing current may have reduced/prevented
damage to the H-bridge chip, and nothing works because the battery is too weak.  Or you may be
unlucky and have let the magic smoke out...
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

skindova

Thanks for the help!
It is actually a 12V battery, but it has only 9.something V because i havn't recharged it for a while...
How can i test if the bridge is ok then?
thanks

jremington

#3
Dec 11, 2016, 04:10 am Last Edit: Dec 11, 2016, 04:10 am by jremington
Wire it correctly and test it with a good power supply. If it smokes, it is dead.

MarkT

A 12V lead-acid battery that reads 9V is irreparably damaged.  10.5V minimum voltage is about it,
and then only if you immediately recharge.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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