jdmarsh50
USA
Asked
— Edited
I recently gutted my daughters Hot Wheels Barbie chopper. I ended up with two 12 volt motor/gearboxes, wheels and a battery. The gearing is rather tight, as the chopper was designed to haul around a 35-40 lb child.
When you speak of servos, is the term "motors" interchangeable with that? Will the EZ Board allow for direct hookup, or will I have to also run a motor controller of some sort inbetween the board and the motors?
Ready to buy one... just wondering what I'm getting myself into...
Thanks!
john
Maybe I found my own answer, but please confirm. Looks like I need a Pololu Motor Controller hooked between the motors and the board....
Having not used but read the tutorial on the pololu motor controller.
I think you will need an H-bridge speed controller. I bet your motors draw way more than one amp.
I think your talking about some more serious motors than most of us are using? (enough to move a small child)
Looks like this is the one:
http://www.sparkfun.com/products/9670
DJ, is that the one you are talking about?
Looks like this is the one:
http://www.sparkfun.com/products/9670
DJ, is that the one you are talking about?
sorry I'm not DJ (and i dont see his reply or what hes talking about)
I dont know how many amps your motors draw but i think i would start at 10 amp (or maybe even 25).
I think its not going to work at 1 or 2 amp...
Ron
Oh here you go: eBay Stepper Motor Search
I use those stepper motors. They are based on the same chipset and a lot cheaper. Now, I sure wouldn't run a big motor with those. But I certainly would use that to control relays :)
You can get relays have dual polarity, so they switch two directions. That would be a fantastic solution. Use the HBridge to trigger relays. You could control the relays with a switching transistor, but that could be dangerous if you don't know what you're doing. Transistors are great if you use a proper resistor and proper transistor, but it could pop the EZ-B if it's connected incorrectly or not protected with a diode from the collapse of the relay coil.
So in short, hbridge with relays
Voila!
Thanks. I had considered that an option. Need to think about motor speed control so the motors don't always run at full speed. Once i work that out, I'll feel ready to use that Mastercard. Thanks for the timely reply.
You won't be able to control the speed very easily with an hbridge with those required amps.
The only real way to have various speeds at that level is to find an industrial hbridge with a PWM input. But that'd be pricey.
So what i'd do is determine the 2 or 3 speeds you need. Then get some real big ceramic resistors. Use a few relays (one for each speed and one for each motor). You won't be able to use the hbridge panel, but you can create a script for each one. Then use the ControlCommand command to trigger them.