Relatively new to CS and currently using a CR10X and PC200w to collect data and drive a number of output actions:turn on/off pumps, lights, etc. Curious to know if anyone can direct me how to control a linear actuator, if at all possible? I figure I can open (extend) the actuator using the simple control function from PC200w, but how to reverse the polarity to close (contract) the actuator. Any ideas, suggestions, example, or leads is greatly appreciated.
* Last updated by: EricVal on 2/28/2010 @ 11:55 AM *
http://en.wikipedia.org/wiki/H-bridge is the circuit you are looking for.
You can do it most simply with four switches or solid-state relays, but then you are dependent on software to keep wo switches on the same side of the motor from being on simultaneously, shorting out the power supply.
In your case I'd go with a DPDT relay for "direction" and another driver for "motor on". Saves two ports and eliminates the failure condition above. Deactivate the "direction" relay to save a little power when you aren't moving.
Thanks for the insight. I'll look into this and I may follow-up with additional questions.
EricVal,
I've worked on some DC motor drives and used this:
http://www.canakit.com/dual-motor-l298-h-bridge-control-ck1122-uk1122.html
Might help you get going a little faster with your project.
Good Luck,
IslandMan
Thanks IslandMan and William.
William: I’ve used low current Crydom SPST relays in the past. Do you have any recommendations for a low current DPDT relay that works well with the CR10X low 5v/1ma output?
IslandMan: Am I understanding this correctly. You connect the (+) control port from the CR10X to the “ENA or B” and (-) to “IN1 or 2” to control the operation of the actuator?
Assuming the actuator requires 12 Vdc to operate:
Connect terminal block CN2 to +12V.
Connect terminal block Motor1 to your actuator.
CN1-1 to CR10X 5V
CN1-2 to CR10X CTRL 1
CN1-3 to CR10X CTRL 2
CN1-4 to CR10X CTRL 3
CN1-10 to CR10X G
Raising CR10X CTRL 3 will enable the motion control for Motor 1.
CR10X CTRL 1 = On and CR10X CTRL 2 off will run the actuator in one direction.
CR10X CTRL 1 = Off and CR10X CTRL 2 on will run the actuator in one direction.
You'll have to figure out a way to shut the drive off when the actuator reaches either limit. Perhaps with the S1 current sense CN1-8.
IslandMan