Trouble with the H bridge

So I have an SN754410 H-bridge and i have copied the wiring schematic and code from this web site ( to the t. I have just done one thing differently, i am using bench power supply... but nothing is happening! I have been putting in 20v because i know the motor will run off of 20v and i have changed the PWM to max (255) still nothing. Any suggestions?

It's Not identical then.... I'm not trying to sound all nit picky... but are we supposed to assume that you correctly provide Vcc1 with 5 Volts for LOGIC and Vcc2 with Motor Driver Voltage? There is no way we can know that without some form of picture of what you did... (schematic... photo... etc)

A separate supply voltage (VCC1) is provided for the logic input circuits to minimize device power dissipation.
Supply voltage VCC2 is used for the output circuits
i found this on the first page of the data sheet :wink:
so wat are you upto ?
and check the wiring most of the problems are causes by not wiring correctly

I apologize for not making myself clear. what i altered was Vcc2. Instead of supplying 9v from the Arduino i supplied 20v from the bench power supply. i cannot figure out how to insert the diagram on this forum but it may be useful to scroll to the 3rd page of this website and observe the fritzing diagram.

i supplied 20v from the bench power supply

is the bench power supply DC or AC ?
well i just got this doubt as someone else posted does Dc or AC matter :wink:

well i just got this doubt as someone else posted does Dc or AC matter

haha, well I was unsure if the micro controller could use or convert whichever power source it receives.

noOffense i was just quoting so that that person doesnot misunderstand me :sunglasses: