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Topic: Do i need capacitors (Read 9366 times) previous topic - next topic

Grumpy_Mike

Servo motor.
100uF to start with but if you get trouble use a Pi filter.

zaxarias


Servo motor.
100uF to start with but if you get trouble use a Pi filter.

it's a Tower pro micro servo..
Take a look here,https://learn.adafruit.com/adafruit-arduino-lesson-14-servo-motors/if-the-servo-misbehaves , suggests a 470uf capacitor..
Also, servo acts as a dc motor(needs a non polarized capacitor) ? i mean can we add an electrolytic capacitor to a servo ? or it needs one with no polarization(ceramic) ??
z.p

Grumpy_Mike

There is not much difference between the two values of capacitor in practice. There are no precise answers when it comes to large decoupling capacitors because it depends on too many factors that can not be calculated, or they are more difficult to calculate than to just try. Having too much capacitance is no trouble, having too little is.

You only need non polierised capacitors when the voltage across that capacitor changes polarity. With a servo the supply is constant all the polarity reversing is inside the servo, your capacitor will never see this.

zaxarias

#33
Jul 21, 2014, 10:12 am Last Edit: Jul 21, 2014, 10:14 am by zaxarias Reason: 1
Mike ,how about the voltage rating of the capacitor? The modules work at 5V, can i use 16,25,50,63 or 100V capacitor ?
I guess it should be something close to 5V right ?
z.p

TomGeorge

Hi, use 16V caps, any higher voltage and you will only be wasting space, just make sure you fit them with the polarity the right way.

Tom..... :)
Everything runs on smoke, let the smoke out, it stops running....

zaxarias


Hi, use 16V caps, any higher voltage and you will only be wasting space, just make sure you fit them with the polarity the right way.

Tom..... :)

Are there any electrolytic capacitors less than 16V? I can't find one!!!
z.p

Grumpy_Mike

A voltage rating is just the maximum voltage you can use. You must not exceed this voltage but it is good practice to use a capacitor at 80% or less below the rated voltage.
Yes you can get 5.6V capacitors but 16V will do just fine.

TomGeorge

Hi, if you dig, like E14 or RS parts suppliers you can get 10V caps.

Don't use 5.6V on 5V, to close to rated tolerance.

I have the job of repairing 3phase current monitors, they have a 5V rail and all the 6V electrocaps have got bigger and failed.
No skin of my nose, 6 caps per monitor times 150 monitors, good earner for me, pain in rear end for customer.

Tom..... :)
Everything runs on smoke, let the smoke out, it stops running....

zaxarias

Thanks for the replies, so i will get the 16V capacitors...
z.p

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