paper: Talon, Victor884, Victor888, and Jaguar speed vs torque tests

[EricVanWyk]

Originally Posted by Ether

Links should be fixed now.

Here's an interesting visual. I wrote an awk script to read and convert the RPM vs Nm @ fixed IPW¹ raw data into a family of closely-spaced RPM vs IPW @ fixed Nm curves and plotted it with gnuplot. You can really see the change in linearity of the 884 as the load on the CIM increases.

Also, FWIW, here's a graphic of the 884 driving a 1500 ohm resistive load. You can see how linear it is. The non-linearity (when connected to a motor) comes from the interaction of the (slow) frequency the 884's output with the motor's inductance.


¹ input pulse width

Thanks Ether! I am going to steal that first chart for when I teach Class-D amplifier design.

[Joe Ross]

Has anyone tested a TalonSR to see how close it is to the original Talon?

[Gdeaver]

Our team used talons last year. 8 Total on our swerve module. No failures no problems. We have always put 20mm height EBM- Pabst fans on them. We have a big box of them from previous years. My one most important observation. Our RS-540 steering motors have never run as cool as with the Talons. Original talons not SR's. In a hot warehouse this summer (95 F) our drivers went crazy and drove non-stop for over an hour with only quick battery change for rest. Our steering motors never went over 140F. Our drive cims hit 160F for a short period. The steering motors are in a positional application- go this way no go back this way no go this ways continuously. A Nasty life for a motor and controller. I submit after this observation that the original talons locked anti-phase modulation as opposed to the sign magnitude modulation of the other controllers is superior in a position application that is always hunting and requiring motor reversal. And now they are gone. Do we use last years talons on our 2014 robot or the new SR's ?? I can not prove this with instrumentation we don't have but the observed difference is huge.

[James Lightfoot]

I am a rookie mentor, so this reply is coming long after your work, but I still wanted to thanks. When I fist read the User Manual on the Talon, I thought that when it stated a 100amp inrush/60amp maintained w/ a fan for constant loads > 30amps that there was all kinds of headroom. After looking at your charts, I see that my initial thought was wrong.

Thanks for the effort and details.