Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: robotvisionary on July 07, 2007, 11:08:18 PM

Title: Resistors question
Post by: robotvisionary on July 07, 2007, 11:08:18 PM
Hey i have a question on resistors.

I know something about resistors and i have build 4 robots with simple intelligence with no programming. but this is my first time with a robot that is programmable and i am doing the $50 dollar robot but i cant find the exact resistors specified. Can i buy can 330 or 470 ohm resistor without frying the circuit board? Also can i buy a 1k ohm resistor without frying the L.E.D.


P.S.

For the ones that may answer buy it from DigiKey. Don't post that because i live outside of the USA i live in Puerto Rico. Still part of the USA but not a state. >:(
 And a order of $10.47 cost me in shipping 20.00 and I made two orders. One that cost me the shipping 20.00 and another one that the shipping was 23.00. So pls don't put as an answer DigiKey. :)
Title: Re: Resistors question
Post by: robotvisionary on July 07, 2007, 11:47:27 PM
For the ones that want to see my robots.

Click the hyperlink. http://web.mac.com/fjseda/iWeb/Site%202/Photos.html (http://web.mac.com/fjseda/iWeb/Site%202/Photos.html)
Title: Re: Resistors question
Post by: KambeiX on July 07, 2007, 11:55:26 PM
In simple terms, there are resistors used for limiting current and resistors used for cutting voltage.

Resistors in series with LED are used for limiting current. For 5V you can use 220-1K resistors and you will do fine. Lower value will give you a brighter led but also it will consume more energy. Values too low will cause your Led to fry.

As for voltage-cutting resistors, it will depend on the current requierements of the circuit, but if you are dividing 5V in half, then if the schematic uses 2 1K resistors in series you could use values close to that as long as they are the same (2 470 or 2 1.5k)

But if there are sensors or transistors involved, you should use what the schematic says unless you know well what you are doing :P

Title: Re: Resistors question
Post by: robotvisionary on July 07, 2007, 11:57:24 PM
Thanks  ;D

Title: Re: Resistors question
Post by: KambeiX on July 08, 2007, 12:03:50 AM
Also if you can use eBay take a look at these auctions

http://cgi.ebay.com/50-Value-1-4W-Metal-Film-Resistors-1R-10MR-1-2000x_W0QQitemZ230149499959QQihZ013QQcategoryZ73147QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/1N4007-1N4148-1N5819-2N3906-2N3904-assoeted-kit_W0QQitemZ230148304776QQihZ013QQcategoryZ4666QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


All the resistors, transistors and diodes you will ever need

Title: Re: Resistors question
Post by: robotvisionary on July 08, 2007, 12:06:18 AM
Also if you can use eBay take a look at these auctions

http://cgi.ebay.com/50-Value-1-4W-Metal-Film-Resistors-1R-10MR-1-2000x_W0QQitemZ230149499959QQihZ013QQcategoryZ73147QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/1N4007-1N4148-1N5819-2N3906-2N3904-assoeted-kit_W0QQitemZ230148304776QQihZ013QQcategoryZ4666QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


All the resistors, transistors and diodes you will ever need



I was thinking in using Radioshack not the best parts stor but it will have to do. Thanks though. ;D