Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: RS232 on July 06, 2010, 08:06:00 AM
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Hi, I am trying to make my first robot. I am trying to order parts but it seems that the 1.62K ohm resistor is on back-order on digi-key until mid August. It is also out of stock at mouser and everywhere else for some reason. Is there some other resistor or series combination I can use to make this work? Thanks!
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The resistors don't have to be spot on, so something around 1.62 would do fine, or a combination of two resistors to make something close to 1.62 would work too.
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So do resistors in a series act like batteries in a series?
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Put resistors in series and you can pretty much + the resistances to get the desired resistance.
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Okay... It seems a bit counterintuitive though. :s
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Yeah, but if you cant get that exact resistor... Sometimes this can work as a good fix...
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I'll keep this in mind... Thx
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Okay... It seems a bit counterintuitive though. :s
How is it counter-intuitive? The current travels through one resistor and then the other.
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Because I thought that two resistors of different amounts would just resist as much as the larger one... See what I'm getting at? Like say there was a 100 ohm and a 50 ohm resistor. I thought it'd just have a combined power of 100 ohms, not 150.
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^But as the current passes through each resistor it loses energy. So, it loses energy in the 100 ohm and ten again in the 50 ohm so same as 150 - as long as in series... In parallel its different: 1/R1 + 1/R2.
I was wondering if anyone could point me to another possible combination cause I'm not used to purchasing these things and the different ratings for them - I don't want to pick the wrong thing. I found a 1.65K ohm... But why specify 1.62 if a range will work? I'm not yet sure how to calculate all the stuff out to make sure its OK, since I've never put together a complex circuit. I have had an EE circuit analysis class in college, but I haven't mastered that stuff.
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a good combo is 1k and 620 ohm. if you have a radioshack that has electronic components, you can buy that large reel of 1/4 watt resistors which has both resistors.
hope this helps,
Patrick
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a good combo is 1k and 620 ohm. if you have a radioshack that has electronic components, you can buy that large reel of 1/4 watt resistors which has both resistors.
hope this helps,
Patrick
Thanks, those are both on back-order as well. Radio shack has a reel of assorted resistors of all ohm ratings for 1/4? If so, I may try that as I am going to take some stuff back to RS that I found much less pricey on digi-key.
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actually, no. radioshack only has about 30 common resistors in the reel. but i have been able to use them in different combos for circuits, and i haven't bought any other resistors ever. buy the reel!!!!!!!!!!!!!!!!! it's a great buy.
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Order the $50 robot kit from here: http://www.circuitgizmos.com/products/cgsorkit1/cgsorkit1.shtml (http://www.circuitgizmos.com/products/cgsorkit1/cgsorkit1.shtml)
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Order the $50 robot kit from here: http://www.circuitgizmos.com/products/cgsorkit1/cgsorkit1.shtml (http://www.circuitgizmos.com/products/cgsorkit1/cgsorkit1.shtml)
Huh... good suggestion. I'll do that.