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    Producing Quality Computer Tools for Racers and Engine Builders since 1986





Dynamometer Controllers

For Eddy Current, Hydraulic, and Water Brake style absorber dynos.

We offer controllers for most any type of absorber (brake) dyno, electric Eddy Current dynos, dynos with hydraulic pumps for a brake, or water brake dynos.  The dynos can be chassis dynos for testing the engine in the vehicle, or engine only dynos for testing the engine only out of the vehicle.  

Dyno Controller Hand Held.jpg (295360 bytes)  click to enlarge image of new, hand held controller  NOTE:  USB connection is 10 ft long, so controller needs to be within 10 ft of your computer.


Eddy Current Dyno Control System

Standard 120 VAC System

120 V AC input, 12 amp
Up to 12 amp DC output, up to 90 VDC

Optional 240 VAC System

240 V AC input, 12 amp
Up to 12 amp DC output, up to 180 VDC

Some users have put 2 Power Control Units in parallel to provide more amps.  We are still investigating the reliability of this method.

Eddy Current Controller   


Eddy Current Controller with 2 Power Modules (to handle more power absorption)   


Water Brake Dyno Control System  part#  DT4-WBC  (DT4-TC throttle controller is same system without Water Valve and bracket)


Optional SuperFlow tm Actuator  part#  DT4-WBCSF
Dyno-Control-Actuator-for-Superflow.jpg (293221 bytes)  click image to enlarge


Graph showing good repeatability from prototype water brake controller


The Eddy Current controllers get their feedback from RPM, which means the controller is controlling RPM, not power absorption level.  If you do not change the Manual Control knob, but increase power by opening the throttle, the RPM will stay constant.  Also, as you dial the knob up or down, the RPM will increase or decrease as controlled by the knob.  (There is also a manual power level mode, which controls amps to dyno with knob, and does not use RPM feedback.)

The Water Brake or Hydraulic Pump controllers (which control the opening of a valve) use valve position as the feedback, not RPM.  Although RPM feedback would be better, it can also go unstable and produce severe oscillation in the valve and then load and RPM at the engine.  So what we offer now is the more conservative position feedback.  That is what produced the RPM graphs above which shows very good and repeatable ramping up of RPM during the tests.

The typical power test procedure consists of:

Open the Current Readings screen in the DataMite program where you can watch all the dyno readings.
Use the manual control knob to set the engine RPM to a low, starting point RPM.
Open the throttle while the controller holds the RPM to the low, starting point RPM you have manually set.  (See note below for current water brake controller not controlling to RPM.)
Press F1 on keyboard (or use a starting switch, or press "Start Test" button on new hand held controller) to start data recording with the DataMite program
The controller ramps up the engine RPM at the "Ramp Rate" sent in the Controller specs in the DataMite program, shown in the "PID setup screen" document via the link below.
When the engine reaches the Maximum RPM as set in the DataMite program, the controller ramps the RPM down at approximately the same rate to the starting point, low RPM.
Control is returned to the manual control knob.
The DataMite program does its calculations and presents a power curve, the same as done without a controller.


If at any time during the test (when the controller is ramping the engine RPM), you manually move the control knob, control returns to the manual control knob.  This allows the user to override the automatic control should you sense something is not going correctly during the test.

The current Water Brake Controller is not controlling to RPM, but to water valve opening.  When you start your test, the valve opens at a constant, repeatable rate.  This works well for engines which have fairly stable (no big "holes" in the) torque curves.  We're still developing the RPM feedback method, and controllers you purchase now can be retrofitted, probably by just reflashing the PID controller board and updating the PC software.

Latest version of the software lets you do an accelerating test, and now a decelerating test (starting at a high RPM and pulling the engine down to a low RPM).


for an explanation of the LCD screen on the hand held controller.

for an explanation of the PID setup screen for Eddy Current Control and running a test.

for an explanation of additional PID setup screen for Eddy Current Control features.

for an explanation of the PID setup screen for Water Brake Control and running a test.

for an explanation of the screen for finding and setting travel limits for the Water Brake valve actuator.

for the Dyno DataMite v4.1 User's Manual Supplement which also discusses the dyno controller.


What You Need:

DataMite III USB or DataMite 4 USB dyno data logger.


What You Get:

Controller systems as pictured above.

More Information, Download Demo:

to go to our Dyno DataMite downloading page to download a FREE Dyno DataMite Demo.

for movies of our Prototype Brake Dyno Controller.

for prices.



To Order:

Call 248-473-9230. Visa or Mastercard accepted.