### Author Topic: Question about 50\$ robot resistor and RoHS  (Read 495 times)

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#### robotnick

• Beginner
• Posts: 1
##### Question about 50\$ robot resistor and RoHS
« on: November 12, 2010, 11:43:23 PM »
I've been looking quite a bit and it's near impossible to find a 340ohm resistor though the 330ohm ones are easily available.  Would that be ok as a replacement?

Btw, I'm also concerned about my breadboard and breakaway male connector not being RoHS compliant. Are there any precautions I should be taking?

#### waltr

• Supreme Robot
• Posts: 1,944
##### Re: Question about 50\$ robot resistor and RoHS
« Reply #1 on: November 13, 2010, 08:07:06 AM »
Most likely a 330 instead of a 340 Ohm resistor would be fine. If not just add a 10 Ohm resistor in series with the 330 Ohm.

You don't need RoSH compliant parts for hobby building. They are only needed if you are selling your product in the EU market.

#### Soeren

• Supreme Robot
• Posts: 4,672
##### Re: Question about 50\$ robot resistor and RoHS
« Reply #2 on: November 13, 2010, 11:55:02 AM »
Hi,

I've been looking quite a bit and it's near impossible to find a 340ohm resistor though the 330ohm ones are easily available.  Would that be ok as a replacement?
As waltr stated already, 330 Ohm should be fine.

Usually, when you calculate a resistor, you go with the nearest lower standard value. The reason for 340 Ohm mentioned somewhere, might simply be that the designer didn't think too much about who would use the design and so used what he/she had lying around already.

Unless it's for something with critically defined voltage levels or similar, it won't matter because 10 Ohm in 340 Ohm is 10*100/340 = 2.9% and the standard resistors you will use is 5% tolerance, meaning that a 340 Ohm resistor can be from 323 Ohm to 357 Ohm while still being within tolerance.

Btw, I'm also concerned about my breadboard and breakaway male connector not being RoHS compliant. Are there any precautions I should be taking?
The RoHS directive is to lessen the amount of lead in waste dumps and land fills, not to protect you and that shouldn't worry you, as humans cannot assimilate heavy metals in their metallic form.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?