Low Z noise problems

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SymTech Laboratories
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Re: Low Z noise problems

Post by SymTech Laboratories »

neverlift19 wrote:on my board I have tip126 and a quick google search shows them to be in the same family, just slightly different ratings. Am I justified to say its safe to do the modification?
Yes, it's safe to do this modification.
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

thanks I will report back later!
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Re: Low Z noise problems

Post by neverlift19 »

Couldn't find a 50v 470uf cap but I did dig a 25volt off an old brushless speed controller, curious if the voltage is really important?

Thanks
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dontz125
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Re: Low Z noise problems

Post by dontz125 »

You're trying to control flyback voltage, which will be significantly higher than 25v. Are you sure you want a 470uF? The others have been talking about 47, or 0.47 ...
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

Honestly I dont know, I see some using 47uf some using 330uf .47uf I am honestly not sure and some of the links are dead :x I didnt get to go far on my test run... no log..
ka24de-t 12-1 diy trigger wheel
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Re: Low Z noise problems

Post by SymTech Laboratories »

neverlift19 wrote:Couldn't find a 50v 470uf cap but I did dig a 25volt off an old brushless speed controller, curious if the voltage is really important?
The flyback voltage is clamped to 36V, so you really need a 50V+ rated capacitor.
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

ok will get on that tomorrow. So whats the uf rating I 'should' be getting or is that a test and tune type of thing?
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Re: Low Z noise problems

Post by kjones6039 »

FWIW.......

I have been using a 47uF/63v without issue......

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Re: Low Z noise problems

Post by moparmaniac »

Again, I'm using a 47uF 50V polarized (NOT bipolar) capacitor. Solved all of my noise issues.
neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

grr my radioshack is weak, a bunch of non helpful people work there. Almost blank faced when I asked about a polarized 50v 47uf cap... highest they had in stock was 35v so I guess I need to order online or see if anyone has one laying around, still getting voltage spike and sag however its a lot lower! msq below.
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Re: Low Z noise problems

Post by SymTech Laboratories »

RadioShack carries a 100uF/50V capacitor (P/N 272-1044) that should work fine.
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

I'll try that out next! The 47uf smoothed out the intensity a LOT down to within a 2 volts of swing vs 11 volt swings :yeah!:
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

,6 volt swing I can completely live with THANKS YOU GUYS :yeah!:
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880cc
t3/t04e 57 trim 11psi
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ms2 v3.57 on 3.3.1
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Re: Low Z noise problems

Post by SymTech Laboratories »

Great! Thanks for reporting back!
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

after more logs the 100uf has much larger swing than I originally saw, it is closer to a 3 volt swing, found a 47uf 50volt cap I am going to try out today. Update later.
ka24de-t 12-1 diy trigger wheel
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t3/t04e 57 trim 11psi
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ms2 v3.57 on 3.3.1
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Re: Low Z noise problems

Post by Peter Florance »

neverlift19 wrote:after more logs the 100uf has much larger swing than I originally saw, it is closer to a 3 volt swing, found a 47uf 50volt cap I am going to try out today. Update later.
Did you ever perform the sensor ground test?
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neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

yes passed that, as soon as I read that I went and checked took 30 seconds :D
ka24de-t 12-1 diy trigger wheel
880cc
t3/t04e 57 trim 11psi
blaster coil
ms2 v3.57 on 3.3.1
neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

have not logged to see if its smoother yet, been doing wiring and adding stuff :D

should I add this mod to the idle pwm too? have yet to set pwm for idle but its on the list for tomorrow morning.
ka24de-t 12-1 diy trigger wheel
880cc
t3/t04e 57 trim 11psi
blaster coil
ms2 v3.57 on 3.3.1
neverlift19
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Re: Low Z noise problems

Post by neverlift19 »

ok after a few logs this is way worse. Its a very shaky swing of over 4 volts now. Undrivable at night with any electrical load :(
ka24de-t 12-1 diy trigger wheel
880cc
t3/t04e 57 trim 11psi
blaster coil
ms2 v3.57 on 3.3.1
yellowlt1ta
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Re: Low Z noise problems

Post by yellowlt1ta »

I added a 47uf 35v polazided on the center legs of Q3 to Q9 with the negative side on Q3. none of the legs where lifted. is this right? this is on a v3.57

I have been using it like this and still get noise. I have my grounds done the correct way too.
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