I want to use the above card to control a 6v motor that will turn in both directions. What I’m not sure about is the power supply needed for external connection to the card to drive the 6v motor. From what I understand a 6v to 15v external power source can be used with this card. So… if I use an external source of 12v, will the card know that it is driving a 6v motor and limit the output power to the motor to 6v or do I have to try and find a 6v external power source? If it cannot determine the power requirement of the motor, which I imagine is the case, can I limit the the output voltage to 6v to the motor through the card software?
If you use a 12V supply with the 1064_1B, then it will output 12V on the motor terminals when duty cycle is at 1.0 and -12V when it's at -1.0. However, if you set duty cycle to 0.5, the 12V power to the motor will only be 'on' 50% of the time, which is effectively the same as 6V since it's switching from 0 to 12V at 20kHz. So as long as you're careful to stay within -0.5 to 0.5 duty cycle, you can use a 12V supply with a motor rated for 6V.
If I supply 12v and set the Duty Cycle to -0.5 to .5, will the card always remember this setting, providing I don't change it myself? You mention being careful..so that has me concerned somewhat.
Maybe it's safer to just use two 6v 3amp power supplies and connect them in parallel to send 6v/6 amps to the card. this would give me 6v at the motor outputs and plenty of amps to drive the motors. Just seems a lot more stuff to work with but it's very difficult to find a 6v power supply that outputs more than 3 amps. My 6v motors will draw around 2.5 amps (guessing) so I definitely need to supply 3 or greater. Which way would you go?
Either way you're going to have to write a program if you're planning on using a Phidgets controller, and these cards don't have memory on them so it will be up to your program to provide commands to drive the motor. As long as you make sure that the number you send to the setDutyCycle command is between -0.5 and 0.5, you'll be fine. It is easy to create a check to make sure that the dutycycle you're sending that function is within those bounds.
