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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Andrew Borgogna on January 18, 2011, 01:33:24 PM
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Guys the Hacker ESC I got had a ferrous donut on the servo cable. From my experiance in compters these device are normally for suppressing noise spikes from feeding back to other circuits. Basically they slow down the rise time of the spike, at least I think that's what it did. Anyway I sent an email to Will Hubin and asked him if is timers needed it. He didn't think it did but suggested I post this to see if anybody else had removed it. I removed the one on my controller and no problems so far.
Andy
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The cabe makes bifilar winding, so it has no effect on signal on the wire. Its task is to cancel currents oscillating from motor, to receiver and servos, what makes dipol long enough for wawes on MHZ frequencies, It has almost no effect if you have only timer on end of that cable.
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It's almost certainly there to suppress radio-frequency interference. It takes a lot less noise to bother a radio than it does to bother something like a Hubin timer -- you've probably got a better chance of getting struck by lightning in a wingover than you do of having problems from taking the ferrite bead off.
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It takes a lot less noise to bother a radio than it does to bother something like a Hubin timer
Tim
I think you got this backwards based on the other stuff you said. I agree and I would add Will Hubin seem to think it would make no difference with his timer. I passed this by him first before posting it here. Will suggested I post it here.
Igor, if I understood you correctly you don't believe it affects RFI, but is there for current stability from variations in the current load caused by the motor. I can't see any difference in operation with or without the donut. But I don't have a scope to look at the +V wire on the servo lead. It would be interesting to see what the +V and for that matter the ground look like when the motor is running.
Andy
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It takes a lot less noise to bother a radio than it does to bother something like a Hubin timer
Tim
I think you got this backwards based on the other stuff you said. I agree and I would add Will Hubin seem to think it would make no difference with his timer. I passed this by him first before posting it here. Will suggested I post it here.
Maybe I didn't state it clearly -- a radio is going to be much more sensitive to noise, hence you need to reduce the RF noise coming out of the ESC to a much greater extent if it's going to be used close to a receiver.
Igor, if I understood you correctly you don't believe it affects RFI, but is there for current stability from variations in the current load caused by the motor. I can't see any difference in operation with or without the donut. But I don't have a scope to look at the +V wire on the servo lead. It would be interesting to see what the +V and for that matter the ground look like when the motor is running.
If that were an affect it'd be awfully subtle, or it'd only happen every once in a while. I'm voting for RF interference -- that's probably 99% of the ESC market, after all.
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No Andy, I mean it does NOT make any effect for current in wires in meaning supply for receiver, timer or so. The winding is bifilar, means the current going from ESC through red wire to supply the rest of the system (receiver, servos etc, or timer in our case), goes also back through the black wire and they cancel the EMF in the nut each other. The nut is damping only currents going through all wires paralel, and it can be only noise induced from outside (motor, PWM switching, noise from moving metal parts etc) induced to long wire from motor to rest of the system connected on that servo cable. And since we have only one small timer, there is only low chance that something wrong will induce there and that it will be so strong that it needs damping.
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Hi Andy,
You can cut out the ferrite ring, or donut as you called it. I've been playing with my own timers now for a couple of years now, and my governor timer is quite sensitive to spikes etc. I use one of the motor wires to read the rpm continuously and this has some serious noise into my circuit that I filter out. The first thing that I do on any esc that has the ferrite core, is to cut it out, because it's always in the way of something. I've checked this out carefully and there is no problem in this. If it does not bother you, you can always leave it in, but then the wires are too long anyway for a neat installation so you may just as well get rid of it.
Keith R