capacitor/condenser on a rotary

[gezza]

Can putting a capacitor on a rotary machine make it run smoother. Does anyone have a machine with capacitor ... I have a direct drive with a mabuchi rk 370 motor and I would like to experiment , trying to put on capacitor to see is it runs better. And any idea which capacitor / condenser to put on ...


I am not sure is this the right place to post this but I couldn't figured out in which other group to put it...

[Wonderland]

the capacitor will help reduce electrical noise.

[gezza]

But why then is not a standard to put capacitor on rotary machines... I mean not all rotaries have it.

[OwlsDen]

The capacitor has to be matched to the motor and you have to be careful of the polarity once it is installed. Some capacitors will either fail or not run a motor when the polarity is wrong. This can be a real issue with cheap power supplies and clipcord connections.

[gezza]

Woud a ceramic disc type capacitor, multilayered 100nF 50V type fit in ?

[OwlsDen]

http://www.beam-wiki.org/wiki/Reducing_Motor_Noise

I think this may help. It looks like 0.1 microfarad capacitor shorted across the poles will be a good simple solution for signal filtering of the noise a dc motor creates. It gets more complex from there. I would also consider matching voltage of the capacitor to the max voltage of a dc motor. So say you have a 12 volt motor and you would want a 12v 0.1 microfarad ceramic disc capacitor. Hope that helps.

The article goes in to more complex method with mixing capacitor values for extra filtering. Another option would be to string diodes together to create a bridge rectifier. That would act as a filter without adding capacitance.

[gezza]

OwlsDen thank you a lot ! But what is your oppinion is this necessary for rotary tattoo machines ? Actually I have an uncle Roy direct drive and it has a cap on it , i can't figure out whichone it is because the cap is painted.... I like how it is running , and I was thinking to put on other machines as well. But I would like to here the opinion of more experienced members of this forum... once again thank you OwlsDen!

[nivek]

i bought a motor and it came with 2 for my Nedz and his machines have them - they are impossible to read with my 44 year old eyes

[OwlsDen]

It isn't necessary. Even more so the better your power supply the less you need one.. I have put together a few direct drives and the motors came with matched capacitors but I didn't install them. If you feel like your motor isn't running well, you can install one and see if it works better, but shielding a motor is more for protecting the circuit in a power supply. You see the motor spinning creates a second frequency ( basically noise ) in the return voltage ( headed to ground ). This noise can confuse other circuits used to read CPS and duty cycles on some power supplies and cause them to shut off. Again like a i stated before a good power supply will be shielded from this and the noise will just be fed to ground where it will die. Additional circuits on a common ground rail done correctly will have a diode and a capacitor at the beginning to secure polarity and reduce noise, thus reducing the need for a capacitor on the motor. If you were using something with an audio output on the same common ground I would highly suggest shielding the motor, as you might hear it in the audio.


Sent from my iPad using Tapatalk 2