DC motor control using PWM

[koon]

i am currently trying to design a circuit that utilizes a L293D h-brigde. however, i've come to a problem is that NIELVIS does not have sufficient current to run the motor. from other tests, we found that the motor runs at .6 A. please help. the motor's rating is U= 12v . we are using labview 2 generate the pwm signals.

[MikeG]

Thank you for contacting National Instruments. I apologize for the delay in responding; our email box has been overrun lately.

Based on the hardware specifications of ELVIS and the DAQ hardware, you will not be able to source that much current directly. You will need to build or buy external circuitry to amplify the current. You can find examples of how to build a current amplifier in an electronics textbook. There is probably a simple, inexpensive version that you can create with on the breadboard itself.

Again, the hardware you have simply cannot source that much current, so building (or buying) a constant voltage current amplifier is the way to solve your problem.

Regards,
Mike G.
National Instruments Support