AC (Alternating Current) Absorbers

AC (Alternating Current) Absorbers deliver the ultimate in electronic load control. Besides offering load-control response times measured in microseconds and low inertia, they are capable of providing full-torque loading down to zero RPM (allowing stall-testing air or electric motors). Moderate power applications are configured to dissipate their energy into larger external resistive load banks, while for very low power testing, heat dissipation can sometimes be handled by the drive’s internal braking resistors. For applications, in the 200 Hp to 1,250+ Hp range, a regeneration system sends power back into the utility’s grid (for a credit against the user’s electric bill).

Motoring Mode is optionally configurable for  any of our AC dyno applications. Only AC absorbers can do double-duty to “motor” your test engine. In addition to its providing a convenient way to start up the engine, motoring allows testing its internal frictional cranking loads on engine dynamometers or simulate down-hill coasting for road-load dynamometer simulations.

Shaft, C-Face, or other NEMA Frame mounting options are offered in various absorption ranges. Keyed shaft units are commonly supported between a pair of pillow-block bearings – to allow reading reaction torque via a load cell that is linked to the absorber’s trunnioned frame. Flat-flange C-Face models couple with matching bolt-pattern torque transducers and U-joint driveshaft assemblies. Larger absorbers have a set of mounting holes in their housings for fixing them to the dynamometer’s stand or to a reaction cradle/table.

Air-Cooled Eddy-Current Absorbers

Air-Cooled Eddy Current Absorbers offer load-control response times measured in milliseconds, moderate inertia, and high specific load capacity – especially in the lower RPM working ranges of most industrial-type engines. For applications that do not require stall speed loading, an air-cooled eddy-current absorber is usually the most cost-effective electric absorber. Their self-cooled rotors require no external water supply or resistor banks. They also cost less than planetary-driven water brakes and allow far more design flexibility than hydraulic pumps.

3" to 30" Diameter Rotors for loads from under Ľ to over 3,000 foot-pounds. Higher capacities are available from tandem absorbers or via our overdrive systems. Installation options include compact integral PTO drive or trunion mounting – with direct or belt driven shaft drive.

12-volt DC, 120-volt or  40-volt AC (input) power supply/controls are available to provide 12, 96 or 192-volt DC PWM (pulse width modulated) output – which is suitable for many DYNOmite or third party absorber models. Loading when using these controls is adjustable – either manually (using either its panel knob or the built-in 0-10 volt analog control input) or automatically via digital PID output leads from the DYNOmite data-acquisition computer. Panel circuit breakers are matched to the customer’s application, protecting the absorber’s windings.

Liquid-Cooled Eddy-Current Absorbers

Liquid-Cooled Eddy-Current Absorbers offer load-control response times measured in milliseconds, very-low rotating inertia, and compact high-specific load capacity. Compared to water-brake absorbers, they are especially well suited for applications that require plenty of low RPM torque capacity - as do many industrial-type engines. For applications which do not require motoring or stall-speed (zero RPM) loading, our liquid -cooled eddy current absorbers offer more cost-effective loading than equivalent capacity AC absorber (motor) and drive can. For applications that demand high RPM limits, lower system inertia, and continuous-duty (temperature independence)  water-cooled eddy-current absorbers are the ideal solution.

We manufacture these absorbers in both single and multi-rotor configurations, in a number of diameter ranges to cover testing everything from tiny 20,000 RPM two -stokes to 1,200 Hp diesels. Rotors are added to increase power capacity, without limiting peak RPM, while rotor diameter is increased for boosting low-RPM torque capacity. Since we manufacture these units in-house, we machine and balance the rotors for the application, wind custom voltage coils, and assemble the ideal stack-up to get the just the load curve you need. Their modular design also allows for the possibility of upgrading capacity if your test engine's increase in size someday.

 

Planetary-Driven Absorbers compactly couple the high-power absorption characteristics of water brakes to the high-torque requirements of low-rpm axle-shaft testing. These are some of the earliest high-capacity hub-mounted dynamometers. Our custom built, toroidal-flow units are available in capacities to over 2,000 HP (per axle). Because they are packed in billet-aluminum housings, it is still possible for one man to lift and mount the units.

Load control is done via either a manual control valve or with any of our larger capacity electronic auto-load servos. These systems use the same line of load valves as all of our other large water-brake absorbers.*

 

Water-Brake Absorbers