
On Mon, 01 Jan 2007 19:48:15 0500, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@xxxxxxxxxxx> wrote:
>kontiki wrote:
>
>> kontiki wrote:
>>
>>
>>>Hi, does anyone know where a reference table of parallel resistors
>>>could be found?The table is very useful for quick accurate resultant
>>>resistances (to two places of decimal), the tables I've got are from
>>>Practical Electronics Jan. 1990? and have faded to the point of being
>>>unusable.Most nonstandard resistance values are easily ascertained
>>> e.g.for 17 ohms>75//22
>>>quickly and easily!
>>> with thanks,
>>
>>
>>
>> thank you for your replies....the "math" is fine,....
>> lets say I want to shunt a 120k res. to get a
>> 15.6k how long does it take to find the required value? a table is much
>> faster ,and if you are limited by values "at hand" again an alternative
>> pair is easily/quickly chosen.This is useful for establishing the
>> practical effects of temperature compensating resistors and
>> thermistors.
>> I tend not to fire up the pc each time I need to do the math...
>>
>2 ways.
>You just reverse the standard method..
>
>(120K*15.6K)/(120K15.6K) = 17.931K which is what you need.
>
>Personally i like this one.
>1/(1/15.6K 1/120k) = 17931;
>
> I can hit the inverse( reciprocal ) key on me calculator at the
>end instead of starting it off with a 1/(... , this saves in a 2 key
>strokes.
RPN:
15.6
1/x
120
1/x

1/x

