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#16
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#17
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#18
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#19
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Re: Could a magnetic field around CIMs cause fuses to blow?
<anouncer voice> Will team 617 discover the problem with their victors in time? Will they have to do something drastic?! Tune in Monday afternoon to see the exciting conclution to this perplexing problem! </anouncer voice>
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#20
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Re: Could a magnetic field around CIMs cause fuses to blow?
One problem i suspect is you may be using the wrong equiptment with the cim motors. With the Atwood/CIM motors you should use the victor motor controllers between the power source and the motors (which you are using) but what should be bridging from the battery to the victor is a 40amp self resetting circuit breaker. You should only have fuses in the Spike Relays. Below you should be using the ones on the far right at the top of the breaker board for the cim motors.
![]() Last edited by dez250 : 12-02-2005 at 21:40. |
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#21
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#22
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#23
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Re: Could a magnetic field around CIMs cause fuses to blow?
if infact you have 4 wheel drive and too much traction the motors will stall and the breakers will pop
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#24
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#25
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Re: Could a magnetic field around CIMs cause fuses to blow?
OK,
First things first. You first picture clearly shows a wire going to the gearbox and it looks strangely like the red lead of a Chalupa motor. This is a big no no and you will not be able to compete with this arrangement. Next you have a screw missing from motor(+) on one of the controllers which leads me to believe you using a common ground or are wiring motors in series. This is also not allowed and will not work if you plan on backing up. The motor leads on the controllers change polarity, i.e. sometimes the motor(-) is battery negative and sometimes it is battery positive. Lastly, as someone has pointed out, the mounting hardware on your controllers is touching motor(-) again giving a sneak path to frame. 4-40 allen screws work OK but tywraps work and are non conductive. So what was happening? If all is as I surmise above, the motors on the left side are reversed so that the robot can drive forward. With the polarity reversed and the motor and controllers touching the frame, the output of the left side controllers are shorted when driving forward. The opposite condition would be the case if you were driving backward. Make the suggested fixes and try again. That is how the LEDs on the disconnected controllers were lighting when you ran the right side. As to the question about magnetic fields...the answer is no. Yes a wire in the presence of a magnetic field may have current induced in the wire. This is dependent on two things, the magnitude of the field and the field must be changing or the wire moving. Since the motor is a permanent magnet, the field is not changing, and since the wire is not moving there can be no current induced in the wire. Since the motor leads are connected to a fairly low impedance, any induced current would be tiny compared to the motor run current. If you have any further questions you can always PM me. I won't have an immediate answer but I will get back to you. Anyone can ask me questions and I will try to answer. Last edited by Al Skierkiewicz : 12-02-2005 at 23:16. |
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#26
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Re: Could a magnetic field around CIMs cause fuses to blow?
This isn't criticism, only addressing all of your concerns.
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Thanks for you help. All options will be considered. We will look at everyting on Monday when we get back to school. |
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#27
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Re: Could a magnetic field around CIMs cause fuses to blow?
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#28
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Re: Could a magnetic field around CIMs cause fuses to blow?
I just checked the bot. There IS a slight short with the screws in the victors. The resistance isn't infinate, but it is in the 1000 K ohms. The multimeter didn't beep when between the terminals but did between a screw and a termainal. This will be fixed, but I don't know if that was the whole problem.
I rechecked again with someone looking and found that the screws arn't conducting to the terminals. I found that while the wires are distint and not crossed, all of the positive red wires are conducting for each other. I tested from the breaker panel to the victors and all of the red are conducting from each part on the panel on the 40A fuses. I don't know how this works. I can't find any grounds anywhere near the victors. The red wires arn't connected tot he balck wires, but all of the black wires are connected together like the red ones. We are going to re-wire it to track down the culprit. If you have had trouble like this or know what is happening, this tr4ead is still going until there is a cure. In other words, We need more help ![]() Last edited by jdiwnab : 14-02-2005 at 08:49. Reason: Rechecked again |
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#29
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Re: Could a magnetic field around CIMs cause fuses to blow?
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I assume your software is controlling two motors with a "right side" pwm signal, and the other two with a "left side" pwm signal. If you have one left side motor being controlled properly but the other one controlled with the right side signal, they will oppose one another when you try to turn, and you will trip a breaker if you're lucky. Same with the right side, though it sounds like you've never gotten it upset enough to actually trip a breaker, instead just having a motor being backdriven against its will. If you remove the fuse for the wrong-sided motor, that motor will be turned by the other one on the same gearbox, and you'll end up with the Victor getting powered by the generated current. You can either 1) disconnect all your motors and watch the lights on the Victors as you go from neutral to full throttle to full turn, and see which ones respond; or 2) double-check the code, the pwm cables, and the motor wires to make sure they all agree. Since you insist your wiring is correct, your software is at fault, but it'll probably be easier to correct the problem by changing which pwm outputs your Victors are plugged into. |
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#30
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Re: Could a magnetic field around CIMs cause fuses to blow?
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Uh.. Should I be getting contentutiy through the breaker Panel with fuses out? I put one lead on the battery termainal and the other on a termainal for the moters. The resistance was great but I though it should be infinate. Last edited by jdiwnab : 14-02-2005 at 12:38. Reason: more info |
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