While looking at my son's college textbook for basic electronics, I came across three symbols for resistors.

It was the third one which I've never seen before:

 

                         

 

The original version          The IEC version            Non-reactive resistor

 

I've obviously had a sheltered life in telecoms and electronics.

I had to google to find the symbol, to discover it's a 'non-reactive' resistor.

 

Its listed uses include:

Electronic compass, Magnetometry, measurement of magnetic field intensity and direction, Position sensors, Angle position sensors, Rotary position sensors, Linear position sensors, Ferrous metal detection, Vehicle and traffic detection.

 

Are they that common?

To my thinking, resistors aren't really reactive anyway - unless it's a particularly large wire-wound version.

 

maybe the 'obvious' -[ R ]-   was too confusing fore the Masters Degree kid designers?

8 minutes ago, bluesofa said:

Are they that common?

To my thinking, resistors aren't really reactive anyway - unless it's a particularly large wire-wound version.

 

Carbon and metal film resistors are pretty non-reactive at the frequencies we usually work at, but wire-wounds can be pretty inductive unless they are wound to minimise it.

 

 

I was dragged up on "square box" (IEC) resistors but the "wiggly-line" symbol is common enough in older or US diagrams that everyone knows what they mean.

 

And to remeber the colour bands on resistors, I was taught Bad, Boys, Rape, Our, Young, Girls, But, Prefer, Grown, Women !

3 minutes ago, stouricks said:

And to remeber the colour bands on resistors, I was taught Bad, Boys, Rape, Our, Young, Girls, But, Prefer, Grown, Women !

Virgins, Go, Without, for the last three when I learned it.  Violet, Grey, White.

11 minutes ago, treetops said:

Virgins, Go, Without, for the last three when I learned it.  Violet, Grey, White.

 

Ours was persons of color who's parents weren't married <two words 5,8> rape our young girls but virgins go without.

 

Or the PC version Black Beetles Running On Your Garden Bring Very Good Weather.

38 minutes ago, bluesofa said:

It was the third one which I've never seen before:

DigiKey also doesn't know them...

https://www.digikey.com/products/en?keywords=Non-reactive resistor

 

Another type of a current resistor ????

 

Be careful,  with posts like this there is a danger of moving conversation away from viruses,  corruption,  alcohol consumption and lewd behavior...????

8 minutes ago, Puchaiyank said:

alcohol consumption and lewd behavior...

 

It's OK, these is what us engineers does when not doing engineering ????

 

I'm back row second from the right, 1975 RN Apprentices, we were by far the best year for the alcohol consumption and lewd behaviour. Still in touch with a few of the lads.

 

I never could get my head around the resistor color codes...why the hell dont they just print the the number in plain numbers  for example 2.2K

1 minute ago, johng said:

I never could get my head around the resistor color codes...why the hell dont they just print the the number in plain numbers  for example 2.2K

Physically larger ones have just that.  Impractical for smaller ones.

5 minutes ago, treetops said:

Physically larger ones have just that.  Impractical for smaller ones.

 

SMT tend to be printed, 2.2k would be 2k2.

 

I struggle with the really tiny through-hole beasties, often resorting to the meter to verify that the bag label and my reading of the code (with a loupe for flips sake) are actually correct.

1 hour ago, Crossy said:

 

Carbon and metal film resistors are pretty non-reactive at the frequencies we usually work at, but wire-wounds can be pretty inductive unless they are wound to minimise it.

 

 

I was dragged up on "square box" (IEC) resistors but the "wiggly-line" symbol is common enough in older or US diagrams that everyone knows what they mean.

 

Ayrton-Perry - I thought he was a famous golfer?

(sorry)

To go off at a tangent, I remember a company called Reading Wound Components, years ago. They specialised in wire-wound components.

(Reading is a town in the UK in case you're not a Brit)

The point is the two words 'Reading' and 'Wound' can both be pronounced two ways, to allow for plenty of confusion if you didn't know what the company produced or the place.

 

SMD resistor world

222 = 2.2k Ohm

103 = 10k Ohm

1002 = 10k Ohm

01C = 10K Ohm

18D = 150K Ohm

 

R as decimal

2R2 = 2.2 Ohm

R22 = .22 Ohm

1 hour ago, Crossy said:

 

It's OK, these is what us engineers does when not doing engineering ????

 

I'm back row second from the right, 1975 RN Apprentices, we were by far the best year for the alcohol consumption and lewd behaviour. Still in touch with a few of the lads.

 

I was a 1963 TIT. Telecommunications Technician in Training.  We weren't common apprentices but Trainees. ???? Did the 5 years Traineeship. Mostly country lads bought to The Big Smoke. After the first year filing rectangular blocks of iron, cutting our fingers on knives and finding out what STD was we branched into our chosen fields. Out of about 400 who started, not many of us left and probably not a good kidney between us.

1 hour ago, stouricks said:

And to remeber the colour bands on resistors, I was taught Bad, Boys, Rape, Our, Young, Girls, But, Prefer, Grown, Women !

Ours was ; 'Zij Bracht Rozen Op Gerrits Graf Bij Vies Grauw Weer.

(She brought roses on Gerrits grave in dirty gray weather)

 

Zwart (0) Black

Bruin (1) Brown

Rood (2) Red

Oranje (3) Orange

Geel (4) Yellow

Groen (5) Green

Blauw (6) Blue

Violet (7) Violet/Purple

Grijs (8) Grey   (Grauw is a weather fenomen where the sky is colored grey.)

Wit (9) White

 

Gerrit Zei Niks  (Gerrit said nothing)

And the tolerance was Goud Zilver Niks (Gold Silver Nothing, 5% 10% 20%)