Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   Electrical (http://www.chiefdelphi.com/forums/forumdisplay.php?f=53)
-   -   How to fix a problem spike (http://www.chiefdelphi.com/forums/showthread.php?t=113790)

Thad House 17-02-2013 16:28

How to fix a problem spike
 
Today 2 of our spikes went bad, and we would like to know how to fix them if it is fixable. One of our spikes consistently lights up red, and another once consistently lights up green. I opened one of them up, and I cannot see any solder bridges, so I was wondering if it could be internal in the relay modules. Any ideas or should i just wait until tomorrow and call vex?

marccenter 17-02-2013 21:07

Re: How to fix a problem spike
 
Team 4488,

In my experience as an engineer it is unlikely that 2 components have failed due to themselves.. Can you post a little more information about your wiring configuration, what you are trying to do and your software so we can possibly point you in a direction?

Thad House 17-02-2013 21:46

Re: How to fix a problem spike
 
They were hooked up to the compressor, and after a few minutes it is doing what i described. We know it is not a wiring issue because we hooked the compressor up to another spike and it works and is still working hours later. So we have it working now, but are just wondering what to do with the old ones.

Thad House 18-02-2013 18:46

Re: How to fix a problem spike
 
So we now have a 3rd dead one out of the box. We will be calling vex tomorrow and see if they can help.

Gregor 18-02-2013 19:32

Re: How to fix a problem spike
 
3 dead spikes sounds like an issue on your part. Can you describe your wiring, and please include pictures?

Thad House 18-02-2013 20:54

Re: How to fix a problem spike
 
I don't have pictures, but it uses 18 awg wire from a 20 amp breaker going to the spike, then the output is wired to powerpoles which then go to the compressor. Its wired correctly. Thats how we have done it for years. We are using the new smaller compressor. And as of now a new spike is working correctly wired the exact same way.

Al Skierkiewicz 19-02-2013 08:08

Re: How to fix a problem spike
 
If you have not replaced the fuse in the spike with a breaker you have simply blown the fuse in each spike. The compressor draws significant current when it starts. It is legal and recommended that you replace the fuse on the spike used for the compressor with a 20 amp breaker.

Thad House 19-02-2013 12:08

Re: How to fix a problem spike
 
We were using breakers in 2 of them, and a fuse in one of them. In the one the fuse was in it was still good and was not blown. Plus if we pull the fuse the light turns off like it's supposed to.

jwakeman 19-02-2013 14:27

Re: How to fix a problem spike
 
I believe I found a bad spike last night while trying to get our compressor running. The behavior i saw from the spike is similar to what the original post described. Here is what my experience was:

1. Using 20 Amp snap breaker in the spike. Using the Compressor class in WPILib. Before the robot was enabled, solid orange LED on the spike. Once the robot was enabled the Compressor code would turn on the relay on the DSC (confirmed, little green light lit up as expected) that the spike was connected to. This resulted in the LED on the spike turning off (no color).

2. Removed the compressor leads from the output side of the spike. No change. Spike LED still off.

3. Removed the pwm cable from the spike. LED turn RED. Measured -10V on the output of the spike.

Replaced the spike. All worked fine. I did notice the pins on the pwm were pretty mangled when i removed it from the spike the first time (step 3 above) and it is possible not all three pins were seated correctly and this may have had something to do with the failure of the spike.

Al Skierkiewicz 19-02-2013 14:56

Re: How to fix a problem spike
 
Ok,
I am going to state this as it is not entirely obvious. The input to a spike uses the same cable (PWM style) but does not feed a PWM signal to the spike. If the spike is not changing state as the LEDs next to the relay outputs on the DSC, then the likely culprit is the PWM style cable. Unlike the PWM outputs that feed a Victor, the center pin is used for the relay outputs.
Theoretically, the spike should not lock to an output when the cable is pulled. So as you have found, the spike operated normally when replaced.

jwakeman 19-02-2013 15:06

Re: How to fix a problem spike
 
Quote:

Originally Posted by Al Skierkiewicz (Post 1236448)
Ok,
I am going to state this as it is not entirely obvious. The input to a spike uses the same cable (PWM style) but does not feed a PWM signal to the spike.

Understand it is not a pwm signal and that we are just using the same cable that is used to transfer pwm signal to the other motor controllers.

Quote:

Originally Posted by Al Skierkiewicz (Post 1236448)
If the spike is not changing state as the LEDs next to the relay outputs on the DSC, then the likely culprit is the PWM style cable. Unlike the PWM outputs that feed a Victor, the center pin is used for the relay outputs.
Theoretically, the spike should not lock to an output when the cable is pulled. So as you have found, the spike operated normally when replaced.

Not sure I fully undestood. You are confirming that the spike was bad?

Al Skierkiewicz 19-02-2013 15:08

Re: How to fix a problem spike
 
J,
I was making the statement for those who are lurking so there is better understanding.
Yes, it sounds like the spike was bad. However, there are more reports of spike failure than in any year before. It seems odd for something so simple.

Andy A. 19-02-2013 15:20

Re: How to fix a problem spike
 
Quote:

Originally Posted by Al Skierkiewicz (Post 1236456)
J,
I was making the statement for those who are lurking so there is better understanding.
Yes, it sounds like the spike was bad. However, there are more reports of spike failure than in any year before. It seems odd for something so simple.

Al- I'll just mention here that I had a 'bad' Spike this year, as well. It had a constant red LED indicator, but no current.

I have no idea when it was manufactured, and I chucked it in the trash can after deciding it wasn't worth messing around with. I'll see if it's still there, and if you're interested do a post-mortem. I agree that it's an odd thing to have fail with any sort of regularity- I think i could count on one hand the number of failed Spikes I've seen in 10+ years.

Thad House 19-02-2013 15:25

Re: How to fix a problem spike
 
I emailed VEX and they want to look at it because they think its weird that 3 failed. I've been in FRC for 4 years and I've never had a bad spike.

Al Skierkiewicz 19-02-2013 16:50

Re: How to fix a problem spike
 
Andy,
The only failures we have had were pulled out tabs from over active use. I was able to repair with a soldering iron. No control failures that I can remember.


All times are GMT -5. The time now is 20:13.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi