Only put 5 batteries in the holder, then you will not waste as much power in the voltage regulator on the Arduino, and your batteries will actually last longer!// Per.
Quoteso its better to solder them on the motor,You need both a 0.1uF ceramic capacitor for high frequencies and a large one for the low frequencies. If the motor runs in both directions you need a non polarised capacitor, otherwise an electrolitic will do. The larger the better.
so its better to solder them on the motor,
If you are using PWM, you can still do this, but will need to provide an inductor in series with one or each of the motor terminals - I will "bow out" at this point, of explaining how you should calculate the value.
maybe i should add a bypass capacitor on the 5V output ?
Quotemaybe i should add a bypass capacitor on the 5V output ?You should have a capacitor on each of your three modules, as close to the module as possible.
I am not sure why Paul said that. In general you do not want to make the capacitor that big wired directly across the motor, just a 0.1 uF ceramic. You want the large one across the motor supply not the motor itself. That is the motor and the driver be it simple FET or h- bridge. When you do then you can put an inductor in seriese with the supply and a capacitor the other side. This is known as a pi filter because it resembles the symbol for the maths constant. Google for an example.
(but what about their capacity? electrolytic or ceramic
I think here says that a RC(resistor capacitor) filter can make the PWM wotk fine, right ?
Quote(but what about their capacity? electrolytic or ceramicNot sure what you mean? Use 47uF for the large capacitors.QuoteI think here says that a RC(resistor capacitor) filter can make the PWM wotk fine, right ?No. That is not suitable for a motor. It produces a varying DC voltage, that is not the way to drive a motor and have good speed control.Read about PWM here:-http://www.thebox.myzen.co.uk/Tutorial/PWM.htmlFor a motor you must apply it directly to the motor.Read this on motors:-http://www.thebox.myzen.co.uk/Workshop/Motors_1.htmlFor the motor Pi filter read this, it is the last schematic on the page:-http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html
a 47uf capacitor ,right? Should it be Electrolytic or ceramic?
Really, PWM ,in practice,wont work at all if i just add a ceramic capacitor to each motor?
Quotea 47uf capacitor ,right? Should it be Electrolytic or ceramic? You have no choice, you can't get 47uF ceramic capacitors.
So where was the problem?
QuoteSo where was the problem? You tell me?
That was if you used a big capacitor not a 0.1uF.