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#1




calculating minimum and maximum resistor resistance
hi, i'm new to DC circuits, i'm currently taking DC circuit class in college. i know nothing about DC circuits, as of now i'm having trouble solving these stuff on my homework
on my homework they gave an example 22  Red Red Black Gold  2 2 0 5% and it says (5%)(22) = (0.05)(22) = 1.1 max value = 22 +1.1 = 23.1 min value = 22  1.1 = 20.9 but it doesn't tell alot since there's not steps or info on what to do first... so what do i do with these then? 6.8  blue gray red gold  6 8 2 5% 100  red black red gold  2 0 2 5% 220  red red brown gold  2 2 1 5% if anyone can tell me step by step on what to do i can try to figure out what to do and solve the rest of the problems by myself. thanks in advance =[ 
#2




I don't understand your question.
What you don't understand. If you have 4 band resistor code, then the last band will be golden or silver. And the third band is a multiplier http://en.wikipedia.org/wiki/Electronic_color_code http://samengstrom.com/24614782/en/r...or_Color_Codes For example blue gray red gold = 6 8*100 = 6.8KΩ 5% red black red gold = 2 0*100 = 2KΩ 5% 
#3




The last band tells you about the tolerance of the resistor value. A 5% resistor will have a value that is within a 5% limit of its nominal value.
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#4




I think axedrytouch3 wants to know how to work out the range of values a resistor might have given its nominal value and tolerance.
The reasoning used is as follows 1. Say you have a nominal 22Ω resistor with 5% tolerance. 2. The actual resistor value could be as low as 22Ω  5% of 22Ω 3. Or the actual resistor value could be as high as 22Ω + 5% of 22Ω 4. Do the calculation to find that 5% of 22Ω is 1.1Ω 5. The actual resistor value could be as low as 22Ω  1.1Ω = 20.9Ω 6. The actual resistor value could be as high as 22Ω + 1.1Ω = 23.1Ω A slightly different way to calculate the range is to state that the possible range is from 95% of 22Ω (or 20.9Ω) to 105% of 22Ω (or 23.1Ω) 
#5




This question reminded me of a few subtleties associated with the notion of tolerance.
I've never worked in the component manufacturing area but I presume resistors a made in a process whereby every resistor isn't actually checked to make sure it falls within a certain range of values. I guess samples are taken from any particular batch run and routinely tested for compliance. I assume also that the manufacturing process makes nominal resistor values which are "Normally" distributed. The Normal distribution is assigned a standard deviation σ. In a truly Normally distributed population, 99.7% of all samples would fall within 3 standard deviations of the population mean μ. Suppose a manufacturer produces 100Ω ±5% resistors. Suppose also that the 100Ω production process is Normally distributed with a currently known σ of 2 ohms. What proportion of manufactured 100Ω resistors produced would fall outside of the stated tolerance? So ±5% is therefore ±2.5σ and 98.76% of produced items would fall within the tolerance range. So the manufacturer knows that 1.24% of all produced 100Ω resistors will likely fall outside of the stated tolerance. Would the manufacturer be satisfied with that situation? If not what could be done? 
#6




yes i need to find out the min and max for each of the following
resistor(nominal value) color  1 2 3 4 6.8  blue gray red gold  6 8 2 5% 100  red black red gold  2 0 2 5% 220  red red brown gold  2 2 1 5% 
#7




Well I outlined the method in post #4. You should now make an attempt. Don't just expect to get the answers. Post your working and see how things progress from there.

Tags 
calculating, maximum, minimum, resistance, resistor 
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