Resistors ??

Thread Starter

Dr.killjoy

Joined Apr 28, 2013
1,196
I picked up a batch of resistors off ebay and really like them but I wanted to know what Ohm ratting do you guys use and is it really necessary to 146 value resistor kit or just buy common size ( Whats are common?? ) ???




Thanks
Jason SR
 

wayneh

Joined Sep 9, 2010
17,498
Some kits have varied numbers of the included values, e.g. many more 1,10, and 100K resistors than less common values. But I like having at least some of every value. Pain in the arse when you don't have the one you need.
 

#12

Joined Nov 30, 2010
18,224
My resistor cabinet is 24 values wide by 9 powers of ten tall, from .1 ohm to 56 megs, but if I had to go spare, I'd use the dial on my scope. 1,2,5 times powers of ten.
.1, .22, .47 ohms to 10 meg, 22 meg and 47 meg. That's only 27 values. Useless for 1% analog circuits but enough to do a proof of concept for nearly anything.
 

GopherT

Joined Nov 23, 2012
8,009
Foro the e12 series, (E6 is every other one). I started with the E6 series and evolved o the 12 series. Like #12, I think less is more. e6 is plenty and #12 gets by with an E3.

1.0
1.2
1.5
1.8
2.2
2.7
3.3
3.9
4.7
5.6
6.8
8.2

Repeat
10
12
...
 

#12

Joined Nov 30, 2010
18,224
I have E24 and more. A lot of 1% resistors are in those drawers, but the truth is, an E3 set will get you by for "proof of concept" work. Most of what I do now is on paper. When I have a doubt, I can go to the work bench, usually connect less than 10 parts, and verify any doubt I have in mind. After that, I can pencil whip the rest of the design. Other people use simulators. They are cheaper than keeping an inventory, but they have limitations. It depends on how well you understand a simulator whether you can trust the answers it gives. I don't understand simulators, but I understand this: Electrons can not lie. If a real, physical circuit made of discrete parts works, there is no room for argument.
 

WBahn

Joined Mar 31, 2012
30,088
I agree as well. E3 let's you get at least an approximation for almost anything for proof of concept. Plus, it's easy to parallel or series connect them to whip up something close to intermediate standard values.
 

#12

Joined Nov 30, 2010
18,224
Much like going on vacation, beginners pack heavy. When you look at the landmark experiments done by the pioneers in electronics, the simplicity of the designs is usually the most striking part.

I had to go through years of making and measuring precision designs before it soaked in that the math really works and precision is exactly what you make of it. Now I can look at a 50% error, know where it's coming from, and know whether a properly calculated component will correct that. When you get that much experience under your belt, E3 will get you where you want to go. For beginners trying to get real circuits to work, and to develop the mental leap of trust from theory to practice, I'd think E6 would be sufficient.
 

GopherT

Joined Nov 23, 2012
8,009
Much like going on vacation, beginners pack heavy. When you look at the landmark experiments done by the pioneers in electronics, the simplicity of the designs is usually the most striking part.

I had to go through years of making and measuring precision designs before it soaked in that the math really works and precision is exactly what you make of it. Now I can look at a 50% error, know where it's coming from, and know whether a properly calculated component will correct that. When you get that much experience under your belt, E3 will get you where you want to go. For beginners trying to get real circuits to work, and to develop the mental leap of trust from theory to practice, I'd think E6 would be sufficient.
The same mostly applies to multimeters as well. A meter that gives +/-10% accuracy is good enough for most proof of concept and most digital circuits. Beginners should pay for the fluke 87 when a $5 harbor freight meter can be free with coupon. Spend money on other things until (more / better) is needed.
 
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