I came across this -
"connected with <100R"
Does that mean 100ohm or less? Or is the R something else?
Thanks!
I came across this -
"connected with <100R"
Does that mean 100ohm or less? Or is the R something else?
Thanks!
100R is 100 ohms.
100K is 100 kiliohms (100,000 ohms)
1K2 is 1200 ohms.
1R5 is 1.5 ohms.
(ad nauseum)
Thanks!
What does "less" usually mean? Resisting less, or letting less through?
Resisting less, so more goes thru.
Not sure where R came from, I didn't see that until I started Arduino-izing in Fall 2010.
Oh wow, so this doc is probably wrong -
"[these] pins when connected together with <100R ( mostly 1K will work) will [do something]"
I would agree with you, in that limited context.
I've seen this notation a lot on PCBs that print the value on the board as well. Though this is with PCBs made by the same person. It is kind of nice when people use units and R is easier to type than Omega.
Values are not typically printed on boards tho, just not enough space.
Does make reading schematics a little more convenient, with the couple of formats that Chagrin showed.
Haven't noticed that with other components, or maybe I just don't notice it anymore.
CrossRoads:
I would agree with you, in that limited context.
Sadly that is about all I could get out of these folks.
What would you do, stick a 100R or 1K resistor on at see if anything blows up?
You haven't described the hardware at all, so ... maybe?
This is a control pin for a custom box containing various weather sensors. Some of the pins are used for calibration, one is for a simple "reboot".
It is a little expensive so I would rather not fry it, but even if I did it would not be the end of the world. Should I try with a 100R or 1K resistor first?
1K.
mirith:
I've seen this notation a lot on PCBs that print the value on the board as well. Though this is with PCBs made by the same person. It is kind of nice when people use units and R is easier to type than Omega.
You probably wouldn't say that if you have a greek keyboard(!). Omega used to be rarely
available in the early days of computing (ASCII only), till the MacIntosh came along I think(!)
The 1R5 for 1.5 ohms started as a way of printing component values more reliably I
suspect - a decimal point could too easily be missed or get rubbed off, so things like
4.7k became 4k7 which then stuck. Its called engineering notation, meaning you
don't see it in scientific publications, its effectively "colloquial"
You can find manufacturers using these markings on their SMD resistors. It appears to be documented in the IEC 60062 standard, which also defines color codes on axial resistors, but that's only available if you cough up $100.
Just a quick survey of manufacturers (Vishay, Panasonic, TE Connectivity, Multicomp) they all use the R to designate a decimal point. 100 ohms and above the third digit represents the number of zeroes (101 = 100, 502 = 5000, etc.). The M pops back in around the millions of ohms. As an aside, all four manufacturers use the R, K, etc. notation in their stocking codes (ordering codes).
Another one of those situations where xkcd: Standards applies.