capacitor bank

[Gary]

Can anyone explain the purpose of a Capacitor Bank? Just heard about it and never saw one used....Thanks

[ReddyWatts]

It is used to help smooth the DC input controller voltage ripple under load.

The way I understand it: During a DC ripple the voltage fluctuates up and down quickly. The capacitor charges during the higher voltage and then discharges when the voltage goes lower and fills in the dips. The more you have in parallel (capacitor bank) the more it will hold up the voltage during a dip.

[Fluid]

They are standard on some high-end controllers. My Schulze 40-160 has five for instance, and they will add four more if asked. Lower-end controllers often have just one or two.

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[detox]

I wonder why Castle Creations has not designed a capaciter bank for use with their Hydra ESC's. Insted Castle recommends using atleast 8500mah batteries. In a 4s setup it would take TWO 4s 4250mah packs wired parallel to achieve this VERY HEAVY 8400mah MINIMUM rating.

http://www.castlecreations.com/support/documents/neumotors-castle_boat_apps.pdf

[detox]

Here's ETTI version:
http://www.offshoreelectrics.com/pro...d=etti-cap-bnk

[Chop]

So by smoothing out the peaks and valleys it's better for the ESC making it more reliable? Or extending its life?

[Heath M]

will the Etti bank work with a Hydra controller and is it worth adding?

Heath

[Bill-SOCAL]

Yes, the Etti will work with a Castle controller. There is nothing magic about them. I know at least one person running the Etti with a CC. He says he runs a bit cooler and has a bit more power. The ripple current works a bit like backpressure for the lack of a better way to describe it. By removing that or smoothing it out, the motor and controller work more efficiently.

[Heath M]

thanks Bill i might just invest in one

[Chop]

The ripple current works a bit like backpressure for the lack of a better way to describe it. By removing that or smoothing it out, the motor and controller work more efficiently.

Thank you Bill - That explains the "Why do it?" question.

[properchopper]

While sharper minds may take issue with my reasoning here, I installed a cap bank on the UL-1 SC on my LSO mono; the reasoning is , since the SC has a fixed LVC and I need to run for 4 min in LSO, the cap bank may smooth out the downward spikes momentarily pushing the LVC below threshold. Whatever !

[Bill-SOCAL]

While sharper minds may take issue with my reasoning here, I installed a cap bank on the UL-1 SC on my LSO mono; the reasoning is , since the SC has a fixed LVC and I need to run for 4 min in LSO, the cap bank may smooth out the downward spikes momentarily pushing the LVC below threshold. Whatever !

Actually the caps store energy and release it to fill in the lows, so it is not likely that you need to worry about it.

The early Spektrum radios had an issue with low voltage "brown outs" causing a lock out which due to a long re-boot time caused a few crashes. Their solution was a small cap added to the receiver to fill in the "lows" as it were. The current generation recovers faster and is less prone to brown outs, but on the early ones it was an issue which they solved with caps!

[AndyKunz]

It was more Quick Reconnect that fixed the problem, Bill. Caps help prevent power glitches from resetting the micro, but Quick Reconnect is what prevents the crashes. Software, not hardware.

Andy

[Fluid]

In a 4s setup it would take TWO 4s 4250mah packs wired parallel to achieve this VERY HEAVY 8400mah MINIMUM rating.

Frankly I don't see a problem, this is not "VERY HEAVY" for today's power levels. As it is I have to add lead weight to most of my boats to keep them on the water and get maximum speeds, even with 2P. (My 4S2P setups use 4400 or 4500 mAh cells.) Those who want high power (over 120 amps) but think they need ultra-low weight too, are just not going very fast for very long.......


Back to the OP's subject - I solder two additional caps onto my Castles' board to add 50% to the total 'capacity'. Quick, easy and cheap.


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[Bill-SOCAL]

It was more Quick Reconnect that fixed the problem, Bill. Caps help prevent power glitches from resetting the micro, but Quick Reconnect is what prevents the crashes. Software, not hardware.

Andy

I guess I was not as clear as I could have been Andy. My point was that early on, before "Quick Connect" got going that the caps were the interim solution. DO a quick review of which was offered first and I think you will see that the caps preceded the quick connect solution.

The real point was to illustrate what the caps do.