Capacitor value ?

Anchises

Hi,

Can anybody say what the value of this capacitor is ?

I think disc ceramic 4.1 nanofarad ?

3 Bands Yellow Black Red

Maybe 41 * 100 = 4100 picofarad = 4.1 nano ?

http://www.photobox.ie/album/2742761241

A.

martinsvi

black is zero, so that should be 4nF

watty

Black is Zero, 0
(Brown is 1)

So either 4nF or if the Yellow is really Orange, then 3nF (I've never seen 4nF, but have seen 3nF).

Except in high voltage and/or High power, ceramic cap failures are almost unknown. Why do you need to know value?

Anchises

Ah ! Of course Black *is* ZERO .... Sorry for confusion.

So 4000 = 4nf would be correct.

I'm just curious. ( I took it out to check it, because it's markings were invisible on the pcb, standing up between caps and a heat sink. It reads as 80 nf on my meter.)
I don't like the illogicality of it appearing to be 4nf, by the color, but reading something else.
80nF could be within the tolerance to be nominally 100nF

It looks like a decoupling capacitor - it sits from pin 1 (Vcc ) to ground on a amplifier chip TBA810B. Pin 1 also has a smoothing cap of 100uF. But 4nF seems wrong somehow.

Reading the color backwards (as suggested to me on another forum) gives black, red , yellow = 1, 0, + 2zeros = 100nf , a common value for decoupling.

I'm studying an amp module from a old radio (1980s) - identifying the components, and trying to relate them to a schematic. This doesn't seem to be in the schematic, even tho it's original to the pcb.

The color schemes on caps are always confusing. In this case, it seems to academic.

I'm fairly certain the colors are Yellow , Black, Red from the top down, and you would normally read color bands that way.

A.

Fuzzy Clam

Anchises wrote: »

Ah ! Of course Black *is* ZERO .... Sorry for confusion.

So 4000 = 4nf would be correct.

I'm just curious. ( I took it out to check it, because it's markings were invisible on the pcb, standing up between caps and a heat sink. It reads as 80 nf on my meter.)
I don't like the illogicality of it appearing to be 4nf, by the color, but reading something else.
80nF could be within the tolerance to be nominally 100nF

It looks like a decoupling capacitor - it sits from pin 1 (Vcc ) to ground on a amplifier chip TBA810B. Pin 1 also has a smoothing cap of 100uF. But 4nF seems wrong somehow.

Reading the color backwards (as suggested to me on another forum) gives black, red , yellow = 1, 0, + 2zeros = 100nf , a common value for decoupling.

I'm studying an amp module from a old radio (1980s) - identifying the components, and trying to relate them to a schematic. This doesn't seem to be in the schematic, even tho it's original to the pcb.

The color schemes on caps are always confusing. In this case, it seems to academic.

I'm fairly certain the colors are Yellow , Black, Red from the top down, and you would normally read color bands that way.

A.

you say it reads 80 nF on your meter. Thats interesting.
I have an identicle cap (looks the same make) but Orange, purple, yellow which is 370000. i.e. 370 nF.
On meter it reads only .037 micofarad which is 37 nF.
If I read the bands from the bottom up, it would be 47 nF but i doubt it would be 10 nF out.

Fuzzy Clam

Anchises wrote: »

Reading the color backwards (as suggested to me on another forum) gives black, red , yellow = 1, 0, + 2zeros = 100nf , a common value for decoupling.



A.

Yellow, black, red backwards is red, black, yellow

Anchises

See !

Now you know why i'm puzzled

A.

Anchises

This was suggested - that the 'red' is probably Brown.

Using the colours in the Bn, Bk, Yw, order would make it a 100nF, a common value for decoupling.

Dealing with fading aged colors does not help either.

Strange that your (Fuzzy Clam) colors seem mis-matched also.

Maybe in Poland/Russia they had different color schemes in the Eighties ?

A.

watty

There has only ever been one colour scheme everywhere for components (resistors originally). Dates from late 1920s or early 1930, but might be earlier.
There were quite different colour schemes for colours of Battery wires in USA & UK in 1920s/1930s.

0 Black
1 Brown

2 Red
3 Orange
4 Yellow
5 Green
6 Blue
7 Violet

8 Grey
9 White
More or less same as Rainbow, except for black and brown at start and at the end Grey then White

Good details here
http://www.radiomuseum.org/forum/for_beginners_prefixes_and_codes.html

Do note TOLERANCE!
Decoupling capacitors can be 20% or even 40% tolerance as the exact value doesn't matter. 100nF can easily read 80nF due to tolerance and also many cheaper meters are only 5% to 10% accurate (Full scale of range, so on wrong range WORSE).

100nF Brown Black Yellow is VERY likely for a decoupling cap. I use daylight or good halgoen. Worst is LED and cheap CFL usually worse than older type tube because the more efficient a CFL is the poorer the colour rendition.
Even an ordinary filament bulb shows colours more accurately than CFL or LED, though skewed (more red, less blue).
LED have EXTREMELY discontinuous spectrum and the WORST colour rendition of ANY light source. You can simulate almost any colour temperature and "goodness" of White with Red, Green, Blue LED or laser or CRT phosphor. But that is USELESS for illumination except for grey to white monochrome surfaces.
i.e. Red + Green light in varying proportion looks like Orange or Yellow or Olive. But real paint, flowers or other pigments that are yellow to orange by absorbing all other colours in White light will look dark and may even be black or some other residual colour under RGB light.

Get better rendition lighting.

Note 37nF reading for a 20% 47nF capacitor is easily possible, worst case, if meter is 2% out, as it's about 21%. If a multilayer ceramic capacitor is soldered too long the silver dissolves in the solder and capacitance reduces.