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Topic: I will PayPal for finished Sketch Chassis Dynamometer with Eddy Retarders! (Read 997 times) previous topic - next topic


Hello World!

I need someone to guide me on the right Path here.

I do have a control System for a Chassis Dyno for Tuning Cars. (Eddy Current Brake)
The System uses a Hall sensor for reading Speed (60 tooth/rev)
The Output for the Retarder is 5V PWM 31.5kHz (0-5v with a RC-filter)

I do have a plan on making a Hub Attached Dynamometer, with one Retarder on each side of the Car.
The Retarders have SCR running on Mainpower (230v AC) controlled with 1-5v DC

The thing i am afraid of is that the retarders will no have equal braking force, with same amount of Current running.

So to the Case!

I will run the PWM Output i alreaddy have, into a Arduino, and straight thru to one of the retarders
(eddy brake A).
Speed Feedback is sent to my controller, and output is calculated.

To maintain equal rpm on the other retarder (eddy brake B) i was thinking of running Speed Pickups from Both Retarders. Have the Arduino calculate the Output to the other retarder (eddy brake B)
with some PID magic.

Short version:
Actualy run same signal to both retarders, but get a Arduino to Trim the output on Eddy B to maintain equal rpm.based on pulses from Hall sensors with 60puls/rev

Something to understand better!


What i need, is actualy a Slave PID Speed Control to maintain equal rpm.
I have done some programming, but is kinda rusty.

Regards Lars


Whoever takes this on needs access to the hardware for trials/debugging.

Where are you?




Hi There!

Im in Norway!

Access to Hardware, is a bit overkill! (The Retarders are like 250kg each)

Have done some more research, and i looks like i can use the PID Spindle-Speed you will find everywhere online. (Cant post code, i am on iPad)
But need to change the AnalogRead for another "Interrupt" Input reading speed of the Master
Retarder. Also need to Reverse the regulator.

Reverse Regulator i know how.
Coding for Reading the Master is the case!

I have done some coding earlier, so i slightly into it.

Regards Lars

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