Voltage Output of Victors vs. Jaguars

Hi all,

While cleaning up our 2009 electronics board today, our team decided to measure the voltage output of the Victors and Jaguars. We with an 11.3V battery that the Victors were outputting the full 11.3V, but the Jaguars were only at 9.1V. We checked five Jaguars and two Victors, and each had the same result. We also checked the code and it is giving a full +1 and -1 to the Jaguar/Victor, and the Jaguar and Victors all are initialized properly as being either a “Jaguar” or a “Victor.”

Has anyone else noticed this issue with the Jaguars not giving full voltage even though the code is giving it a +1 or -1? If so, we might have found the reason why our drivers wanted to switch back to the Victors on the drive motors.

Thanks.

This is a quick reply, but I think there might be a way to calibrate the Jags. I remember there being a way on the Vics (a paperclip pinhole), I’m looking at a Jag right now and I see something that says “User” on it.

Edit: Luminary Micro - Jaguar - Getting Started Guide - Look at page two under calibration

Why would you be running with such a low charge on your battery?

It’s charging again. :slight_smile:

It is the user button. As I remember the callibration steps you press the button, wait for lights to change, change input to full forward, wait for lights to change, change input to full backwards, wait for green/red blinking.

I edited my original post, but here it is again

Luminary Micro - Jaguar - Getting Started Guide - Look at page two under calibration

We’re doing a test with and without load with an oscilloscope right now. I’ll see what we find out. Also thanks for the Jaguar calibration PDF. I’ll try that too.

Update:

We tested our configuration with a new battery, an oscilloscope, and put a load on the Jaguar/Victor, and the problem went away. What we did find, however, was that the pulses coming out of the Jaguar were much cleaner (as a lot of people already know).

Thanks everyone for your input!

Eugene,
In the first test you were likely seeing the frequency response of your meter between the two devices. Victors are at 150Hz while Jaguars are at 15kHz. Meters in general are not accurate above 500Hz. As to the second test, please indicate what you used for a load and your definition of “cleaner”.

We connected the CIM powering our feed to the Victor/Jaguar for our load. By “cleaner” I mean that on the oscilloscope, the waveform of the Jaguar output was more square, and the victors had a lot of noise. Also, as you mentioned, the frequency of the Jaguars was much higher.

Eugene,
The noise you were seeing is the brush noise produced by the motor. Since the brush repetition rate is is much slower than the rep rate for the Jaguar, it was not as evident as the with the Victor. The noise should be the same when viewed under the same settings on the scope for both controllers. The greater noise is produced in the motors when the brush leaves a commutator segment and the inductance of the motor winding gives and “inductive kick” that produces an arc. Just like an arc transmitter, this arc produces wideband noise which you are seeing on the scope.

If you wanted to test and compare the two controllers without the noise induced by a motor, you could use a 10 ohm, 25 watt resistor. It would give you a light load, but enough of a load to give you good data. Here is the simple math.

E/R=I 12volts/10ohm = 1.2amps
IE=P 1.212= 14.4watts
or
(EE)/R=P (1212)/10=14.4

The resistor will get fairly hot, so watch your fingers!

Thanks everyone for your advise. It makes much more sense now.