Banebots motors inductance
 

Does anyone have inductance specs for the 2011-legal Banebots motors?

This information is not listed on the Banebots website.

I have placed a question with Banebots support but didn't get a response.

In lieue of (or in addition to) inductance, does anyone have scope traces of current in stalled (locked rotor) Banebots motors being driven by Jag and Vic?

Thanks.

Re: Banebots motors inductance
 

I just got off the phone with Banebots.

They don't have (or won't reveal) the inductance of their motors.

Would someone with access to a scope be willing to run a short test on an RS775 with the rotor locked and powered by a Black Jag at 20% PWM output, and post the trace of voltage and current at the motor?

A cruder (but still useful) test would be to hit the locked-rotor RS775 with a 12V step input of duration at least 6 milliseconds and record the voltage and current trace.

I can get the inductance from the curve.

It may be necessary to run the test with the rotor at slightly different rotational positions because of the brushes.

I do not have access to the necessary test equipment or I'd do it myself.

The inductance of the motor is a necessary piece of information to answer some questions that have been asked about power consumption of the RS775 under various stall conditions.

Re: Banebots motors inductance
 

If someone out there has an infrared thermometer you could also stall the motor and measure the heat buildup. Then use simple calorimetry to determine how much energy was converted to heat. It won't be accurate because of the geometry and materials in the motor but should certainly differentiate between 40W and 200W heat conversion. I would do it but we are using the 775s on our drive and I don't feel like subjecting them to that torture.

Re: Banebots motors inductance
 

Is there anyone with access to an impedance bridge who would be willing to measure the inductance of the RS775 (locked rotor) and share your results?

I have written a simulation to demonstrate the current waveform in the RS775 under stall conditions; all I need is an inductance number and I will run the simulation and post graphical results.

merci tres beaucoup !

Re: Banebots motors inductance
 

Is there anyone with access to a function generator who would be willing to measure the inductance of the RS775 (locked rotor) and share your results?

I have attached the procedure and the derivation of the formula.

Re: Banebots motors inductance
 

So many engineers here, and no one can help? ChiefDelphi... don't fail us now! :)