Cap banks - the pre-emptive answer

[Mike Caruso]

Words Vs pictures
remember these numbers ... ...
C= 470uf cap, low ESR, rated voltage ~ 25% above your pack voltage
2 in parallel c1+c2=940uf
2 in series offers C1xC2/(C1+C2) = 235uF !!!!!!
series (-)---[C1]---[C2]---(+)

That series pair in 3x parallel array offers 705uf
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)
(-)---[C1]---[C2]---(+)

Initial charge of the 6 caps is same as if all were individually charged

OMG Ive written and rewritten this a few times and each time I start expanding on referenced detail that loses most people.

simply..
In this circuit, the charge/discharge speed is 8x the std , thus smoothing the DC line ripple more effectively ... even though the energy return availability is 705/2820 ( std6 caps ) .. it presents 8x speed of charge/return into of those original individual 6 caps.. gives us twice the total energy available, at a far higher return rate than std. ( 705 x 8 / 2820 )
In the 15S300A5698/910 example I used a total of 1410uF as detailed here, and logged ripple <0.19Vdc.
Unfiltered, ripple measured >1.6Vdc .. but I didnt enjoy the lacklustre performance so I went home...
I use cap banks as detailed to cover both yield(battery recharges the caps) and reply(esc demand on power system) needs of the system.
------
I read above .. What is DC ripple ? . When the esc fires a phase, it draws energy from the 'energy sump' .( DC batteries ).. this causes a sudden voltage drop evidenced by a blip on the voltage display of your oscilloscope.
Each 3 firings ( a rotation of the motor ) makes 3 tiny blips ..... eg at 30,000rpm there are 90,000(at least) tiny blips.. a ripple .. an induced frequency.....EMF inciting ESR .....
This ripple.. creates an AC that is not usable by the DC-AC inverter (ESC) thus the esc now sees lower voltage...V x Kv - zoomzoom
Capacitor banks reduce the size of that ripple, the esc sees higher nett voltage = more fun.

If the cap bank is too large, it will induce it's own ripple as it recharges.


Would I recommend this type of cap array if asked .. depends on your application.
Im sure to edit this once Ive seen it in a fullscreen.. and read it as a mini-novel.
W

For one I would like to thank you because I love to learn! Now at 63 years old I REALLY want to run over 100 MPH more than just once. HA Mike

[drwayne]

Well I have made a tread about the unsoldering stuff, and got so my ears hung down for my poor a.. soldering job. I have been soldering for ages, some 200 playstation chips, loads of para/serial connections, lipo packs etc for my boat's and flying buddy's, but all of a sudden my serial cabel wich I had used for a long time came unsoldered. Then I made another one with higher G wire, all fine on 45-90c lipo, and then on 65-130c unsolder again, and the boat feels slow so I'm willing to try everything to see if it helps.

How looooooooooooooooooooong are your leads ?

Anybody care to tell me what these little buggers do. One of them was 'eaten' on a bit, and was loose. No way I'm getting it to stick to the board again. So is it a rip on this 180 ?

Take a close up of the top,and show what details are embossed.
W.

[drwayne]

For one I would like to thank you because I love to learn! Now at 63 years old I REALLY want to run over 100 MPH more than just once. HA Mike

You're most welcome.
Run over 100mph ?.. I just wanna walk fast ..but that's a 2 bourbon story.

[maxmekker]

'How looooooooooooooooooooong are your leads ?'


hehe, I have both (now) while I did some new ones I did both a short and a longer one. I'll make a super short one and flip the lipos the other way with the wires comming out closer to the ESC.

Question, again, how about making the serial like it is on the stock esc that comes with the proboat mystic/geico.. Will it mess up the cell count( I don't use auto) you think , since it's a bit hard to plug both lipos at once if I make the serial on the ESC. Go bullet you say. Well I like the safety having a serial cabel made.

PRB4018-250.jpg



'Take a close up of the top,and show what details are embossed.'



Will make a zoom pic when back from work. But it has a grove into it where there should be a tiny solder point.

[drwayne]

'How looooooooooooooooooooong are your leads ?'
[ATTACH=CONFIG]83536[/ATTACH]
.

Yukko
Dean's connectors ( and clones ) are best suited under 4S 80A.. they gain resistance under high load ( they heat up quickly )

Your series connectir great.. for a low draw setup.
try something like this attached for shorter total lead length. fewer plugs.. and use 5.5mm plugs for higher Tx with lower dTemp.

Waiting for your pic !
W

series.JPG

[maxmekker]

I use ec5 on all. I use deans in my 1/16 tanks only :-)

I have looked at the bullet type connection you have a draving off there, I'm afraid it will blow up on me when I mess it up ( it will happend :-)
my system is t180 leo 4074 2000/2150kv 4s 45-90c / 65-130c ,640, 642 m445 props. Should be in the safe zoone.

pics later man, thanks for helping out beond the tread issue

[drwayne]

I use ec5 on all. I use deans in my 1/16 tanks only :-)

I have looked at the bullet type connection you have a draving off there, I'm afraid it will blow up on me when I mess it up ( it will happend :-)
my system is t180 leo 4074 2000/2150kv 4s 45-90c / 65-130c ,640, 642 m445 props. Should be in the safe zoone.

pics later man, thanks for helping out beond the tread issue

If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique !
If you're worries about plugging it together wrong. pay attention!
and ..
batteries ...
female5.5 on battery positive
male5.5 on negative.

esc
positive is male5.5
negative 5.5female

whatever number of series cells you use.. they will all 'daisy chain' together to feed your esc.
Just be wary that last inline connection .. ZAP!

It's good keeping some topical posts on this thread.. keeps it at top !
and some others may gain help from the info.
W

[maxmekker]

If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique !

are you mokking me ? hehe :-) I can solder bullets. it's what you say next, '' If you're worries about plugging it together wrong. pay attention!''

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.

[drwayne]

My daughter wants permission to write an educational mockumentary about this thread's participants ...

If you cannot solder 5.5mm bullets, your friends are correct about your soldering technique !

are you mokking me ? hehe :-) I can solder bullets. it's what you say next, '' If you're worries about plugging it together wrong. pay attention!''

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.

[maxmekker]

Here you go doc.

[tlandauer]

I know how it's done, it's just bullet proof with serial, and the system I have is not like a SAW boat so it should be ok. Maybe in the winter month's here in Norway I will sit down and convert over to bullets.[/QUOTE]
You should "bullet proof with bullets" drwayne is right, I made the change and never looked back. When I connect, I make sure my ex-wife is not around so my mind is in sound condition.
By the way, that thing fell from you ESC, the close up picures look like it fell from outter space. I too want to know what is it. I am learning alot from this post!

[Steven Vaccaro]

great thread! Thanks Doc!

[drwayne]

Here you go doc.

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ??

That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.

great thread! Thanks Doc!

Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

[egneg]

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ??

That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.





Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

Nothing visible Doc.

[properchopper]

That's rooted, mate !
hahaha
I hope someone with a T180 can supply us with the details as embossed on their undead Surface mount capacitors .... ?? That being said.. a 47pf ceramic cap would do nicely as an alternative.. ensure the existing remnant(s) are removed before you add new.





Very pleased to spoon feed information to an appreciative audience, Steven.

0¿0

W

This is an early (non "additional cap board equipped) T-180


DSC03494.JPG