Victor 883 problem, please help.
 

Hello,

I have 2 x victor 883s that I bought 10 years ago that were used with my lightweight. They have since been collecting dust, but I will be re-using them for an RC car project.

I have a working futaba 6XAS converted to ground use. This radio and reciever work perfectly fine because I've used them on my car.

I am getting the blinking orange light with the victor 883, both of them in fact. I switched the PWM cables and it still happens. I connected the leads correctly, everything is hooked up solid.

I tried to recalibrate the victor but it is still blinking orange.

Sometimes the motor blips for a split second, as if it gets a signal for a short time and then breaks up.

I don't know what to do, I really want to use these ESCs. Can someone point me in the right direction?

Thanks,

Re: Victor 883 problem, please help.
 

Did you check the PWM connector?

Re: Victor 883 problem, please help.
 

Also note that some RC systems can not drive a victor. They make a signal l driver for them - 14.95$.

Re: Victor 883 problem, please help.
 

I used this same exact system a few years ago and it worked perfect. Nothing has changed except time.

In any case, what is that driver you talk about? Can you show me where to get one?


Ether how do I check the PWM connector? What do I need to look for and at which end? I have the cable with the little microchip shrink wrapped in the middle of it PWM connector, it is the right one because I've used it before many times on this setup.

Re: Victor 883 problem, please help.
 

Check to see if the connector is properly seated into the Victor.

Go to the link I posted, and click the link in the upper-right corner to see the whole thread.

Read post #4 of that thread.

Re: Victor 883 problem, please help.
 

http://www.vexrobotics.com/victor-speed-controller.html
Under add-ons.

Re: Victor 883 problem, please help.
 

Oh you mean post # 2 :)

I see I have to do this jiggle thing... I REALLY hope that is my only problem, if you solved it I will get you some cheap beer.

Gdeaver that is exactly the cable I have.

Re: Victor 883 problem, please help.
 

No, post#4 of the thread I referenced:

Re: Victor 883 problem, please help.
 

Oh I thought you mean post 4 of this thread. Nevermind I got the idea though.

I will try this.

Thanks for the help!

Re: Victor 883 problem, please help.
 

Hi again,


I tried wiggling around the PWM cable in the victor, while it was on and look for signs of the orange blinking light to go away. It wouldnt, I had my reciever on and my radio on while doing this, victor 7.2v power supplied to it.

It wont show signs of PWM pick up. I am not really sure what else could be causing the victor to not see the signal.

Re: Victor 883 problem, please help.
 

Did you try removing the connector and inspecting the pins, as suggested here?

Did you measure the voltage at the connector to make sure there really is a signal?

Re: Victor 883 problem, please help.
 

I have two PWM connectors and two victors. No matter how I swap them, the same thing happens.

How should I measure voltage at the connector? Straight from black pin to red pin with a voltmeter? Should I be looking for the 6V my reciever is getting as an output voltage on the red/black of the PWM connector?

I thought the red wire on the PWM connector is unused?

Thanks for the help Ether!!!!


EDIT: forgot to add, why dont I just check continuity between ends of each pin? Will that work or is the PWM filter in the wire going to mess up any type of continuity reading?

I did it anyway, showing continuity at the black pin ends, zero continuity at the red pin ends and 1950 ohms at the signal white wire ends. I am not sure if this is how this cable is supposed to function, something tells me the red wire should show continuity but it isnt?

EDIT AGAIN:

I checked both of my PWM cables, they both are showing identical characteristics. 1950 ohms at the white signal wire, zero continuity at the red and continuity at black ends... So I think that is supposed to be that way.


Heres what I just discovered... If I plug the PWM cable into the victor and then into the reciever, it blinks orange...

But, if I take the end of the PWM cable that goes into the reciever and I just slightly nudge it such that the pins are barely touching, the motor spins and the light turns green for a split second. If i push it in further than that, blinking orange and motor off. Its just at that precise location where the reciever end of the PWM cable is touching the reciever pins that the motor freaks out, mind you the radio does not affect the throttle at this point and it happens for 1 - 2 seconds.

If I attempt to play around with the cable by wiggling it, it flicks the motor on and off through the ESC but other than that, no control via radio.

Re: Victor 883 problem, please help.
 

DB,
The 883 in particular, will show some difficulty in fully inserting the PWM cable into the input connector on the 883. Considering the age, it is also possible for the input sockets to be sufficiently spread so as to prevent a good connection. From the 883 sheet...

Indication: No ORANGE indicator on power up.
Problem: Input power issue or joystick trim tab off
center.
Ed. *Please note that the safety feature of this device prevents operation if the controller powers up with a PWM signal demanding movement. The PWM signal must be at a neutral value during power up.


Indication: Flashing ORANGE indicator on power up.
Problem: No PWM signal.
Indication: Flashing RED indicator after calibration.
Problem: Calibration Failed.


LED Indicator Status
· Green = Full Forward
· Orange = Neutral / Brake
· Red = Full Reverse
· Flashing Orange = no PWM

If you are using a multimeter to measure end to end continuity, you should not have 1950 ohms on any wire. There should be continuity from end to end on all three wires and no reading from any wire to any other wire. This test is performed with the cable disconnected at both ends.

Re: Victor 883 problem, please help.
 

Al is this the case if he is using the PWM Signal Driver? I can't find a data sheet for it but there is some kind of circuitry inline which would explain the lack of continuity he is seeing.

Re: Victor 883 problem, please help.
 

No this is for a straight PWM cable.
The VEX PWM Signal driver requires 5 volts but as I remember some R/C controllers do not put out a PWM at 5 volts P-P. The signal driver simply brings that signal up to the point where the Victor input circuitry can then reliably read the signal. I have never measured a Signal Driver, so I don't know if 1950 ohms series resistance would be valid.

Re: Victor 883 problem, please help.
 

Thanks for the reply Al.

I checked cont in both PWM cables and they are showing identical properties as I described.

I am pretty sure the victor side of the PWM cable is seated, because when I plugged my reciever end into the reciever the motor would flick on for a second. If I wiggled the reciever end, it would flicker again.

Get this, I happened to be resting my futaba radio on the table next to me and my arm bumped into the antenna and then everything started to work.

Once I moved my arm away from the antenna it went back into orange LED mode.

So I unscrewed the back case of my Futaba 6XAS to see if anything was loose. Nothing that I could see. I tried to turn my radio on and nothing. Dead radio, wont turn on.

So I know my ESCs work, but for some reason my Futaba died. Just great!

Re: Victor 883 problem, please help.
 

DB,
I would not conclude that the controllers are working. If the PWM cables are just straight wires there should be no (read zero) series resistance on all three. It may be you have two bad cables. Happens all the time.

What is the model of the receiver you are using to drive the Victors?

Re: Victor 883 problem, please help.
 

Al, see below:

Post#4:
Posts #6&7:

Re: Victor 883 problem, please help.
 

I am using a Futaba 6XAS stock receiver system for any RC car or airplane.

It could very well be i have two bad cables. But i find it odd the resistances of both are almost within 0.1% of eachother at the signal wire.

Re: Victor 883 problem, please help.
 

With everything set up and turned on, and a full-speed command being issued, unplug the PWM connecter from the Vic and use a voltmeter set for 15VDC to measure the signal voltage between the two outer pins (black and white) of the connector.

Re: Victor 883 problem, please help.
 

This will not read 5 volts. You may not read anything depending on the device in the PWM cable since it would be pulled up in the Victor by the internal power supply and opto coupler.

Re: Victor 883 problem, please help.
 

The PWM Signal Driver cable that the OP said he was using gets its power from the receiver via the red wire¹. The signal driver cable then sources the current required to drive the Victor's PWM input².


@DBFIU: If you aren't getting a voltage signal at the Victor end of your PWM signal cable (as described in earlier post), check to make sure the cable is getting power from the receiver.


¹ http://www.ifirobotics.com/victor-88...r-robots.shtml

² http://www.robotcombat.com/products/IFIW-SIG36.html

Re: Victor 883 problem, please help.
 

thanks for the help guys it is greatly appreciated.. i am going to test my reciever and cables right now.

Re: Victor 883 problem, please help.
 

A run-of-the-mill digital volt meter connected between signal and ground on the output end of the PWM cable sending a standard Victor spec signal (from a cRIO) will read:

Neutral = .75v
Forward = 1.0v
Reverse = .5v

The meter reading isn't bothered by the pulsed nature of the PWM signal.
(These voltages are as measured)

P.S. Joe reminded me that the IFI signal voltage was lower, and I'd assume that the signal driver cable would mirror those lower voltages that Joe listed.
However, the PWM voltage I measure off an old pBasic IFI controller has neutral at .32v, rather than .375, so some variation between controlling devices should be expected. If the OP measures the signal cable output, please post the voltages you get for our future reference.

(For completeness for those robotics teams wanting to measure this on a cRIO, a Jaguar range signal will read:

Neutral = 1.49v
Forward = 2.29v
Reverse = .67v

Re: Victor 883 problem, please help.
 

I couldn't find a spec anywhere for the period of a "standard Victor spec signal".

Is it 20ms period with 1ms, 1.5ms, and 2ms pulses at 5v for reverse, neutral, and forward? And is this what the OP's Futaba 6XAS is sending?

If so, and assuming that the voltmeter on DC setting responds to the algebraic average of a PWM signal, then one would expect the meter to read (2ms/20ms)*5v = 0.5 volts at full forward.

On the other hand, if the meter on DC setting responds the the RMS of the signal, then one would expect the meter reading to be sqrt(2/20*25)=1.6V

Re: Victor 883 problem, please help.
 

The attachment shows what the parameters are for the IFI system, the cRIO when used with a Victor, and the cRIO when used with a Jaguar. I suspect the Futaba system would be the same as the IFI system (20ms period).

Re: Victor 883 problem, please help.
 

To toss out another idea, the Victors themselves have been damaged in some fashion. Hopefully this isn't the case, but did you recalibrate the Victor successfully, or did it fail (that is, did the LED change colors appropriately?) You can check the procedure and the colors that you should see here.

Re: Victor 883 problem, please help.
 

Thanks, Mark.

Re: Victor 883 problem, please help.
 

I think the measured IFI signal voltage is lower (than the signal from the cRIO) lower because the IFI period is longer. They both have 5v pulses.

If you look at the chart Joe posted, the following formula holds true for all 3 columns:

S = W/L*H

where:

S is the measured (with a voltmeter) output signal voltage

W is the ontime (pulse width)

L is the period length

H = 5v is the height of the pulse (pulse voltage)


That seems reasonable. The measured (with a voltmeter) output signal voltage "H" would be affected by tolerances off all three terms on the right, as follows:

∆S = (H/L)∙∆W + (W/L)∙∆H - (H∙W/L²)∙∆L ¹

Since you already have a testbed setup there, if you have the time and inclination an oscilloscope trace would reveal which of the three terms is making the largest contribution to the difference.



¹ This is derived from the above formula S=W/L*H for the algebraic average of the signal. I wonder if all voltmeters respond precisely to this metric. If not, that could be an additional reason why the measured voltage differs.

Re: Victor 883 problem, please help.
 

Hello all,

Thank you so much for your insight. I have since replaced my 15 year old futaba controller, it was the main cause of the problem. The Vic was not getting a PWM signal. I have a new controller and it delivers a proper strong PWM signal.

Now there is a new problem. I have a small 550 mabuchi size brushed motor in my RC car. This thing pulls maybe a 60 amps with this 7.2v nimh pack. It is hooked up to my vic 883 and my new controller. If I floor it, it STUTTERS badly.

I calibrated the vic, got the green light for a good calibration. So that worked out. But the stuttering is occuring in both forward and in reverse.

If I dont floor the throttle, it wont stutter. If I pull gradually into throttle it wont do it, only when I got wide open throttle. It might be a large current surge, but how on earth can this little motor affect the vic 883? I used to put close to 200 amps through this vic NO PROBLEM. I dont think it is a current carrying capability. I am not sure where the stuttering problem is coming from now.

Please help if you can,

Thanks

- D

Re: Victor 883 problem, please help.
 

Is the battery protected in some way? What you describe sounds like a protection device cutting in at high currents. Do you have a breaker installed?

Re: Victor 883 problem, please help.
 

If you're only supplying 7.1 volts, a quick increase in current could be pulling the Victor's input voltage down to the point where it doesn't work properly. Are your supply wires dropping too much voltage because they're too long or too high a gauge?

Re: Victor 883 problem, please help.
 

or poor connection quality? as in bad crimps or the like?

also look for wire damage...

Re: Victor 883 problem, please help.
 

All valid points and I think you are all right.

Remember, this victor is used to seeing 12-24v. I am using a 7.2v pack with no cutoff or breaker, its probably pulling 60 or so amps so the voltage is dropping below 6v which I believe it minimum for victors.

I will put another pack in parallel to see if it solves the problem, I anticipate that it will.

Re: Victor 883 problem, please help.
 

I am sorry, the Victor will not work reliably at 7 volts. The internal voltage regulator will drop out at near that input voltage.

Re: Victor 883 problem, please help.
 

Hello everyone,

Thank you all for the suggestions.

Here is where I stand.

I wired two 7.2v nimhs in series for a 14.4v pack. Powered the victor, it ran fine for a few minutes, then it started to do the power cutoff thing again. This was literally 60 seconds from when I started driving around under LIGHT throttle. Literally couldnt have been more than 50 amps I was pulling in very short bursts. The voltage could not have possibly dropped from 14.4v down to 6v because of a 50 amp pull, that just doesnt sound right.

After I took the car back inside, I inspected it, couldnt see anything wrong. I think the wire gauge is a little on the thin side, but it didnt even get warm so I dont see how that could have had an effect within window of just 60 seconds or less.

The power cutoff is strange and it is starting to aggravate me to no end!!!

Not sure what else to do, maybe get thicker wire? Better joints? The joints are regular crimp on lugs and the wire is 18 gauge.

Re: Victor 883 problem, please help.
 

DB,
I think it is telling that you ran for almost a minute before problems started. What are the ratings on your 7.2 volt battery packs? There should be something rated in AH or maH listed onthe batteries label.

Re: Victor 883 problem, please help.
 

Hello,

Thank you for all the help. I figured it out.

I fully charged my batteries and re crimped the connections and it ran fine. The voltage drop was attributed to one of my batteries not having a full charge and the other was charged.

When I was charging the batteries I did them in parallel and for some reason one of them might have gotten lose and the charger showed that it peaked but it really wasnt fully charged.

The car ran great and it really screams on 14.4v!

Thank you guys!

Re: Victor 883 problem, please help.
 

Consider that a confirmation of the typical advice not to charge batteries in parallel like that. Unless you've always kept the batteries in parallel, so that they have experienced the same conditions throughout their life, you're likely to have problems. For example, one battery might charge first and fool the charger into shutting off before the other one has gotten a significant charge.