Ceramic Capacitor, adding some to controller DC rail

[Robinev]

Thanks!

I just placed an order for couple of these GRM55DR72E105KW01L at Digikey.

http://www.digikey.ca/scripts/DkSea...eq=172262473&uq=635672100196530087&DPU=submit

I'll put some on all my Adaptto and Lyen controllers. It will certainly help to protect at high phase amp!

Doc

this are very good caps - i believe the optimal type for modding our controllers. thanks for the nice find.
For my Adaptto upgrade i have used also 250V ceramics. in detail:
4pcs TDK 0,47µF SMD 1812 size X7R 250V on the input (about 1cm long 1mm² wires attached)
3pcs Murata o,47µF Lead Type X7R, 250V on near every FET group

NP0 / C0G types would perform better, but they have less capacitance so more would be needed and they are also much more expensive.

thats how i installed the TDK on lyen 18FET:
far right there is a pair of 2220 size 1µF TDK's

So I can replace with bigger ceramic caps? What happens if they consist of different values? Does it matter much? Trying to find out because my mosfets arrive today and I’d like to test it with peace of mind.


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[zombiess]

I simulated adding more cap to the DC bus at different locations.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=104994

 

[Robinev]

I simulated adding more cap to the DC bus at different locations.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=104994

Thank you for paving the way you guys are geniuses. I’m wondering which rock was I under while this was being discovered... ahh ha moment for me going to Decipher the Scripps provided thank you again

 

[madin88]

So I can replace with bigger ceramic caps? What happens if they consist of different values? Does it matter much? Trying to find out because my mosfets arrive today and I’d like to test it with peace of mind.

Hard to say from the photos. Looks like they sit between DC bus and phase (not between batt + and - as done here), so better use one with the same value.
Can you unsolder another one and measure capacitance? Then take one with 250V or higher with that value.

Zombiess thanks for that answer and your work. So for the most part we were wrong or say shooting on sparrows with cannons when doing those mods.

 

[Robinev]

So I can replace with bigger ceramic caps? What happens if they consist of different values? Does it matter much? Trying to find out because my mosfets arrive today and I’d like to test it with peace of mind.

Hard to say from the photos. Looks like they sit between DC bus and phase (not between batt + and - as done here), so better use one with the same value.
Can you unsolder another one and measure capacitance? Then take one with 250V or higher with that value.

Zombiess thanks for that answer and your work. So for the most part we were wrong or say shooting on sparrows with cannons when doing those mods.

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[Robinev]

So I can replace with bigger ceramic caps? What happens if they consist of different values? Does it matter much? Trying to find out because my mosfets arrive today and I’d like to test it with peace of mind.

Hard to say from the photos. Looks like they sit between DC bus and phase (not between batt + and - as done here), so better use one with the same value.
Can you unsolder another one and measure capacitance? Then take one with 250V or higher with that value.

Zombiess thanks for that answer and your work. So for the most part we were wrong or say shooting on sparrows with cannons when doing those mods.

I can unsolder but I don’t have a esr tester
I understand now I’ll take one to an electronics shop which there aren’t a lot of nowadays. 250v I’m thinking what other devices uses this cap between DC buss bar to phase
Or similar circuitry

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[Robinev]

I simulated adding more cap to the DC bus at different locations.
https://endless-sphere.com/forums/viewtopic.php?f=30&t=104994

Will this help my situation what caused the caps to blew up?


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[peters]

Usually there is no capacitor in that position, but it mitigates the HF ringing amplitude and frequency that happens with low-Coss MOSFETs (that IPP120N20NFD is - if it's the part number). The value is definitely lower than a few nF, most likely 1nF, but may be even lower than that. Better to measure anyway.

 

[Robinev]

Usually there is no capacitor in that position, but it mitigates the HF ringing amplitude and frequency that happens with low-Coss MOSFETs (that IPP120N20NFD is - if it's the part number). The value is definitely lower than a few nF, most likely 1nF, but may be even lower than that. Better to measure anyway.

Thank you better safe then sorry I’ll source a esr testing kit


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[Robinev]

Shit blew up again [emoji1431]god help me accept the things I cannot fix and the courage to fix the things I can....


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[Robinev]

Usually there is no capacitor in that position, but it mitigates the HF ringing amplitude and frequency that happens with low-Coss MOSFETs (that IPP120N20NFD is - if it's the part number). The value is definitely lower than a few nF, most likely 1nF, but may be even lower than that. Better to measure anyway.

Could hall sensor error cause mosfets to explode?


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[peters]

Could hall sensor error cause mosfets to explode?

Not really. Overcurrent or overvoltage (either Vgs or Vds) or overheating can kill the mosfets. Maybe there is a short-circuit somewhere on the board or on the cables.
What happened exactly? Did you replace the 45 mosfets and they were all or some of them killed again? Did the motor start or not at all?

 

[Robinev]

Could hall sensor error cause mosfets to explode?

Not really. Overcurrent or overvoltage (either Vgs or Vds) or overheating can kill the mosfets. Maybe there is a short-circuit somewhere on the board or on the cables.
What happened exactly? Did you replace the 45 mosfets and they were all or some of them killed again? Did the motor start or not at all?

Well initially thinking I ran over a tree branch. Causing a motor leads short. Also the 12v isolated source may have been low battery causing coil to Flick on off. It weld in on position when I connected a fully charged battery the thing poofed magic white smoke. I did replace the mosfets and I’m certain that I may have over looked a short to ground. Obviously since I powered on successfully and as soon as I selected reverse and just a little bit of throttle and bang busted some mosfets. didnt count probably the 40x. I’m wondering if I size the caps not by values but by its intended use on an freestyle fpv drone esc from my parts bin. So now wondering if the caps at different values may be the culpit .Going to probe every solder joint and check in microscope. For faults double triple checking this time. Any advice what I could cross reference?


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[Robinev]

Could hall sensor error cause mosfets to explode?

Not really. Overcurrent or overvoltage (either Vgs or Vds) or overheating can kill the mosfets. Maybe there is a short-circuit somewhere on the board or on the cables.
What happened exactly? Did you replace the 45 mosfets and they were all or some of them killed again? Did the motor start or not at all?

Well initially thinking I ran over a tree branch. Causing a motor leads short. Also the 12v isolated source may have been low battery causing coil to Flick on off. It weld in on position when I connected a fully charged battery the thing poofed magic white smoke. I did replace the mosfets and I’m certain that I may have over looked a short to ground. Obviously since I powered on successfully and as soon as I selected reverse and just a little bit of throttle and bang busted some mosfets. didnt count probably the 40x. I’m wondering if I size the caps not by values but by its intended use on an freestyle fpv drone esc from my parts bin. So now wondering if the caps at different values may be the culpit .Going to probe every solder joint and check in microscope. For faults double triple checking this time. Any advice what I could cross reference?


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[peters]

These caps only reduce the EM emission, not protect the FETs, but should all be the same value, otherwise there is probably oscillation between the parallel FETs. But this oscillation shouldn't kill the FETs anyway. High voltage caps are needed, as madin said, not from a drone.
There may also be gate driver circuit error, maybe one or more FET Vgs are always at high level that causes cross-conduction at start. After unsoldering the bad MOSFETs, try to power on and measure the gate driver outputs, they should be 0V. Or without powering on, check if there is any short between the driver outputs and the driver power supplies.

 

[Robinev]

These caps only reduce the EM emission, not protect the FETs, but should all be the same value, otherwise there is probably oscillation between the parallel FETs. But this oscillation shouldn't kill the FETs anyway. High voltage caps are needed, as madin said, not from a drone.
There may also be gate driver circuit error, maybe one or more FET Vgs are always at high level that causes cross-conduction at start. After unsoldering the bad MOSFETs, try to power on and measure the gate driver outputs, they should be 0V. Or without powering on, check if there is any short between the driver outputs and the driver power supplies.

Ok I found

These chips have continuity with input pin gound and one other Pin. busted I’m assuming. And are all the gate drivers equal? I found some gate
Drivers on another device a lipo battery charger.


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[peters]

No, there are many different gate driver chips, this one is an IR2106S. It is not isolated so the first phase short may have damaged several other components also. But this chip is a low output current one, I'm not sure it drives the 10 parallel mosfets directly.

Hard to give a good advice at this point, not even sure it is repairable, and whether it worth to continue or not depends on your knowledge and practice in electronics. You'd need to reverse engineer the circuit, draw the schematics, understand how it works and find the faulty parts, but then you may still end up throwing it away and buying a new controller.
I don't recommend hacking at this level if you don't exactly know what you should do, because your motorcycle with this power is not a toy.

 

[Robinev]

No, there are many different gate driver chips, this one is an IR2106S. It is not isolated so the first phase short may have damaged several other components also. But this chip is a low output current one, I'm not sure it drives the 10 parallel mosfets directly.

Hard to give a good advice at this point, not even sure it is repairable, and whether it worth to continue or not depends on your knowledge and practice in electronics. You'd need to reverse engineer the circuit, draw the schematics, understand how it works and find the faulty parts, but then you may still end up throwing it away and buying a new controller.
I don't recommend hacking at this level if you don't exactly know what you should do, because your motorcycle with this power is not a toy.

Ok I’ll dig into it i pulled up the data log. I did pickup a used sevcon gen 4 s2 off of a recked zero xu... that’s what I want to use if this doesn’t. Play out the way I hope it would. The sevcon my friend that worked for zero was going to help me but he got sick not confirmed with virus but he thinks it was he gave to his hole family and I’m not trying to see god any time soon. So have to figure out witch one I hate more ic repair or IT software repair eventually I have to doo both. Is it possible to program the sevcon with third party software? I found one on gethub but after reading it didn’t mention motor setting or it sounded vague. I’ll order the parts IC’s I tested and already made offer on eBay for these chips. I knew they were busted I was too lazy to confirm last time i repaired it. I also have a Friend that does X-ray tech for NDE nondestructive testing. I worked with him before he could X-ray the board for me if there’s multiple layer coper boards I can find out which trace is busted. I doubt it it broke any thing more then the gate drivers I’ll order the caps it reads hop this esr meter is accurate

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[peters]

10nF is more than what I guessed, but can still be normal as the voltage rise and fall times limit the power dissipated on the cap ESR.
About sevcon I don't know anything.

 

[Robinev]

10nF is more than what I guessed, but can still be normal as the voltage rise and fall times limit the power dissipated on the cap ESR.
About sevcon I don't know anything.

I very much appreciate your responses. I wish you and your family best of health in our time of crisis. I’ll update this post as soon as these chips get here
I just hope to god the mcu isn’t exploded

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