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Electronics => Electronics => Topic started by: Mastermime on May 31, 2012, 07:18:50 PM

Title: Do I need capacitors, diodes, etc?
Post by: Mastermime on May 31, 2012, 07:18:50 PM
Hello everyone,

Do I need capacitors or diodes to smooth out the voltage/ reduce electrical noise even if Im using the Sabertooth 2x25?  I am using two 24 volt 400 watt scooter motors.

Thanks

Title: Re: Do I need capacitors, diodes, etc?
Post by: jkerns on June 01, 2012, 07:02:45 AM
The answer is simple: It depends.

First, look at the specifications for your motor driver - are diodes already built in? If so, you are good. If not, adding them would be a good idea.

And about your motors - are they brush-less or brushed? Brush-less motors are a lot quieter electrically than brushed motors.

Finally - what else do you have going on? Are you using A/D converters? Are your sensors sensitive to noise? How much will some jitter on the analog inputs impact whatever it is you are trying to do?

Those are the things you need to figure out to determine if your particular application really needs a couple caps / diodes or not.
Title: Re: Do I need capacitors, diodes, etc?
Post by: Mastermime on June 01, 2012, 07:48:35 AM
Ok thanks

Quote
And about your motors - are they brush-less or brushed? Brush-less motors are a lot quieter electrically than brushed motors.
The Sabertooth only takes brushed motors.

I am using temperature sensors that are connected to the A/D converter so I need to reduce the jitter to a minimum. 

I'll check to see if there are diodes/ caps on the board.

Thanks again
Title: Re: Do I need capacitors, diodes, etc?
Post by: jkerns on June 01, 2012, 10:33:12 AM
You may consider caps on the motor itself even if they are on the board - the shorter the current path, the more effective that sort of thing tends to be.