Is 220R = to 220 ohm

[shane_95]

i have a packet of resistors and it says its 220R, is that the same as 220 ohm?

[deephaven]

Yes. They normally put 'R' because the omega symbol isn't in the standard character set on PCs etc.

[Psi]

you also sometimes see  4R7 which is 4.7ohms   or  4k7 which is 4.7k

[shane_95]

Ok awesome

[EEVblog]

you also sometimes see  4R7 which is 4.7ohms   or  4k7 which is 4.7k

Easier to say too. "Four Kay Seven" vs "Four Point Seven Kay"

Dave.

[vk6zgo]

you also sometimes see  4R7 which is 4.7ohms   or  4k7 which is 4.7k

Easier to say too. "Four Kay Seven" vs "Four Point Seven Kay"

Dave.

Yeah,one word less!

[caroper]

It is also a lot easier to read on a schematic for us folk with older eyes
1R2 is obvious but if you replace a 1.2 Ohm with a 12 Ohm because you didn't see the microscopic decimal you have problems debugging your circuit.

[vk6zgo]

It is also a lot easier to read on a schematic for us folk with older eyes
1R2 is obvious but if you replace a 1.2 Ohm with a 12 Ohm because you didn't see the microscopic decimal you have problems debugging your circuit.

I have older eyes,but I've never had that problem!

[Rufus]

It is also a lot easier to read on a schematic for us folk with older eyes
1R2 is obvious but if you replace a 1.2 Ohm with a 12 Ohm because you didn't see the microscopic decimal you have problems debugging your circuit.

I have older eyes,but I've never had that problem!

Try it when all you have is a grotty scan to work from like this

[Short Circuit]

I think the decimal point thing has more to do with the quality of reproduction using photocopying and faxing of schematics, back in the days when PDF wasn't yet around.

[vk6zgo]

I think the decimal point thing has more to do with the quality of reproduction using photocopying and faxing of schematics, back in the days when PDF wasn't yet around.

The rectangles for resistors were to save draughtsmen work.
Now we can use wiggly lines like I was brought up on!

[chrome]

The rectangles for resistors were to save draughtsmen work.
Now we can use wiggly lines like I was brought up on!

Not everyone uses that silly symbol for a resistor, over here we use the rectangle.

[Zad]

To my mind, the zig-zag line is the more correct way of denoting a resistor. The rectangle denotes any impedance block, which may be purely resistive, or it may have an imaginary or complex impedance value.  Some standards bodies agree, some disagree...

I tend to use the 4K7 method when sketching, it is easy to lose a decimal point drawn in faint pencil.

[vk6zgo]

The rectangles for resistors were to save draughtsmen work.
Now we can use wiggly lines like I was brought up on!

Not everyone uses that silly symbol for a resistor, over here we use the rectangle.

The point I was making,was that the wiggly line was annoying to draw,hence the rectangle.
With computers,there is no difference in difficulty.
I don't think the wiggly line will ever die out,it is still used by so many people.
The important thing is that we look at a rectangle or a wiggle,& they both say "resistor".

[EEVblog]

It is also a lot easier to read on a schematic for us folk with older eyes
1R2 is obvious but if you replace a 1.2 Ohm with a 12 Ohm because you didn't see the microscopic decimal you have problems debugging your circuit.

Try reading the decimal point on Digikey bag labels!
Next to impossible, and I have perfect eyesight.

Dave.

[shane_95]

Im looking at a CONTINUITY TESTER Circuit, and it says it needs 10k, 30k, and 1k resistors. Does that mean 10,000, 30,000,  and, 1,000 ohm's?

[vk6zgo]

Im looking at a CONTINUITY TESTER Circuit, and it says it needs 10k, 30k, and 1k resistors. Does that mean 10,000, 30,000,  and, 1,000 ohm's?

Yep!
Strictly speaking,the "Ohm" sign should follow "k" in each of these cases,but it is often neglected,because:
 (1) It isn't a letter on the standard keyboard.
 (2) If it is followed by the word  "resistor" in a parts list,or written adjacent to a resistor symbol on a schematic diagram,the "Ohm"
 suffix  is implied.

By the way,a "30k" resistor isn't one of the so-called "preferred values"--you would probably use 27k or 33k.
Why "preferred"?
I could tell you,but it will probably be better explained on the 'Net,if you Google for it.

[shane_95]

I did the google, i now get it

[G7PSK]

Try these links.

http://www.diyaudioandvideo.com/Electronics/Color/

http://www.electronics2000.co.uk/data/itemsmr/res_val.php


http://www.electronics-tutorials.ws/resistor/res_2.html

It also gives the preferred values and the reason for them, start with the last link as i think that it makes the clearest explanation if you read down the page.