doubt regarding l293ne motor driver

[darsanjp]

In the datasheet of l293ne it was said that when the input pin is high the output goes high. but when i actually used it i connected the input pin to +5v and the motor was not working. but it will work when it is connected to 'gnd' . this is the same for all the input pins..why is it like that.. should i use a -ve voltage for all the input pins. please help me out.

 

[audioguru]

Yes.
If the input is high then the output is also high.
If the input is low then the output is also low.

You forgot to attach your schematic for us to see if the IC and motor are connected correctly.

 

[darsanjp]

sorry for not attaching the schematics..

I was actually making a remote control for a 12V dc motor. The RF remote was working properly . But when I connected the data pins from the rf to the input pins of the motor controller it wasnt working. So i decided to check the motor controller. I found that when I supply either INPUT A or INPUT B with +5V, the motor was not working . But when i connect 'gnd' to either of the INPUT pins the motor was working. So instead of +5v , I had to use 'gnd' to control the motor. Is this beacuse the IC is defective or there is something else wrong.The problem is the RF data pins provide only +5V only. ( For testing the circuit i used 4x AA type batteries and the output voltage was about 5.6V and I used the same source for the motor as well as for the motor controller)

 

[audioguru]

Your circuit is missing the extremely important protection diodes shown on the datasheet of the L293. The diodes arrest the high voltage spikes produced by the inductance of the motor. Your IC is probably destroyed.

One input should be low then the motor turns when the other input is high.
The motor is shorted for braking when both inputs are high or low.

 

[darsanjp]

thanks for your reply... i will try it with a new ic