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Posted:
Sat Apr 29, 2006 4:53 pmby Scott
Has anyone made their own servo depression control?
I just got my FP1 w/100" sensor, an am thinking of doing a servo valve. Sorry John, I'd buy yours, but the hobby funds are very limited and I have a bunch of servos laying around.
Any ideas? I'm thinking of a 1/10th scale RC car servo, building the hardware is easy, I'm just not sure of the FP1 and wiring the plug end of things.
Scott
Posted:
Sat Apr 29, 2006 7:09 pmby Tony
Once you have the pressure sensor and the flow control valve, you will also need a PID controller to make it work.
PID stands for "proportional, integral, derivative". The idea is that the flow control valve must respond properly to detected pressure variations. How fast and how far it opens will determine if it will control at all, or become wildly unstable.
If it over corrects, it will probably flutter or oscillate. If it does not correct far enough, or fast enough it will not control pressure very well. The PID controller allows you to "tune" the response of the feedback system for optimum results.
See how it goes, but don't think for one moment that building a stable high performance closed loop pressure control system is going to be simple.
Posted:
Sun Apr 30, 2006 11:44 pmby Scott
In another topic I read, it stated the FP1 has built in PWM set up that will control a small RC hobby servo, thats what I'd like to do, there is even a picture of John's Prototype. I will go over my FP1 doc's again tonight to see if I can find out more about it.
Scott
Scott
Posted:
Mon May 01, 2006 12:04 amby cspeier
Scott
I have one, in fact just until last week I had a prototype. It works perfectly! It's been a dream. For the price, it's worth every penny. I wouldn't build a new bench without it! Set the FP to the desired depression and watch the valve work. Any questions drop me a PM.
Chad
Posted:
Mon May 08, 2006 12:34 amby PFM
Scott,
FYI I used an old throttle body and an Ebay RC car servo and the FP1 as Mouse describes. The setup can be well challenging, you want the latest version from FlowPerformance as it has a bit better setup in it. I still need to tune it a bit as it hunts a bit (my problem) it sure beats trying to throttle the fans as I intended. It also keeps you from switching on a fan that is locked due to vacuum. If you are still having trouble drop me a PM, Mouse was going to send you my email.
Regards,
PFM