Hey all,
I’m working on a student project where we need a high-ish power linear actuator to behave just like a linear RC servo… Meaning we would like to have precise positional control of its stroke using a standard RC Tx/Rx setup. I dont have the acutator in yet, but it does have a built in linear potentiometer for feedback.
Heres the problem though: its a 500lbf 24V actuator. The Jrk controllers look like exactly what I need in terms of interface, but the 12v12 model isnt rated to handle the voltage and the 21v3 model isnt rated to handle the amps. If I were to hypothetically overvolt the 12v12 controller closer to 24V, would it even function? What if I cooled the driver? Would it be better to overamp the 21v3 controller? Am I insane? 
On the other hand, maybe there is some other solution I am overlooking. Some other driver that I have not thought about? Maybe some way to use an Arduino to do my bidding in terms of communication and position control with a higher power driver? Im definitely no software expert, but I am open to any suggestions you guys might have in this regard.
Thanks in advance for all your help!
Ryan C.
Hello, Ryan.
You should not attempt to power the jrk 12V12 with a voltage higher than the maximum operating voltage (16V). This will damage the board. If you do not need the full force and speed of your actuator, you might be able to use the jrk 12v12 to run it at a lower voltage (maybe around 14V). The force and speed of the actuator should be approximately linear to the input voltage, so if your system will still work with a little over half the rated values, this could be an option.
You should also not use the jrk 21v3 if you expect your actuator will draw more current than it is rated for under normal use. How much current is your actuator rated for and how much do you expect it to draw in your setup (at 24V)?
-Brandon
Brandon,
Thanks so much for the response. I would of course like to use the actuator at its full specification (its for a large ground-based aerodynamic control surface), but it may be permissable to use it below its rated spec for testing and prototyping. As for the 21v3 version, determining the max draw is a little tricky because its been custom built by the supplier and they dont really supply a data sheet for the amp draw on these custom deals without a hunk of cash. I would imagine that since its a 24v actuator it probably wouldnt draw more than 5-7 amps doing most things. The actuator isnt really expected to push or pull heavy loads, but rather to just be able to find and hold positions quickly and dynamically.
Ive been messing around with the Arduino PID library in conjunction with your Dual VNH5019 motor controller and Ive had a little bit of success gettng a servo-like setup to work on a different actuator. Do you think that with the proper tuning I could come up with something that emulates the response of the Jrk controller?
I suspect that with proper tuning, you could get the VNH5019 shield and Arduino to work similarly to the jrk. However, please note that the overvoltage protection on the VNH5019 can trigger as low as 24V, so we do not recommend using this motor driver with 24 V batteries, which significantly exceed 24 V when fully charged. Another option might be one of our Simple Motor Controllers or High-Power Motor Drivers.
-Brandon
