What's my resistor?

B

Bill

Guest
Hi All,

I am an electronics newbie, so please be gentle with me! I am trying to
make up a circuit as described on a web site. All it requires is a
couple of connectors, a transistor, a resistor and a chip. It is the
resistor I am having problems with. It is supposed to be a 100K
resistor. I bought one at Maplin for the pricey sum of 9p. But I
wanted to check that it was the correct one, so I used my meter on it.
It has 5 bands: brown, black, black, black, brown. According to my
meter, on the 200 scale, it says 100. On the 200K scale it says 0.1.
surely this must not be the correct resistor (I would have expected to
see 100 on the 200K scale not 0.1). I looked at the Maplin web site
and found a picture of the resistor I bought and it says it is a 100K
resistor - at this point I got confused.

Can someone please help me. What 5 coloured bands should I see on a
100K resistor.


Thanks in advance to any willing helpers.

Regards
 
In article <dgsdgi$j2f$1@news.freedom2surf.net>, Bill <a@a.com> wrote:

I am an electronics newbie, so please be gentle with me! I am trying to
make up a circuit as described on a web site. All it requires is a
couple of connectors, a transistor, a resistor and a chip. It is the
resistor I am having problems with. It is supposed to be a 100K
resistor. I bought one at Maplin for the pricey sum of 9p. But I
wanted to check that it was the correct one, so I used my meter on it.
It has 5 bands: brown, black, black, black, brown. According to my
meter, on the 200 scale, it says 100. On the 200K scale it says 0.1.
surely this must not be the correct resistor (I would have expected to
see 100 on the 200K scale not 0.1). I looked at the Maplin web site
and found a picture of the resistor I bought and it says it is a 100K
resistor - at this point I got confused.

Can someone please help me. What 5 coloured bands should I see on a
100K resistor.
Click to expand...
See http://www.electronics-tutorials.com/basics/resistor-color-code.htm
for an explanation.

Briefly: for the digits, brown corresponds to a "1", black to a "0".
There are three digits indicating the value, one digit which indicates
the multiplier (a power-of-ten), and the final digit indicates the
precision.

What you have, it appears, is a 10001 coding, which means
(100 * 10^0), (1%) resistor. In other words, the color coding says
that it's a 100-ohm 1%-precision resistor, which matches up nicely to
what your meter is saying.

A 100K 1% resistor would be (100 * 10^3), (1%), which would be
color-coded brown-black-black-orange-brown.

A less-precise resistor such as a 5% would have only four bands, with
two digits for the value. A 100-ohm resistor of this sort would be
coded brown-black-brown-gold (10 * 10^1) (5%), and a 100k-ohm resistor
would be brown-black-yellow-gold (10 * 10^4) (5%).

In the European system of writing resistor values, it's usual to write
an "R" or "K" or "M" in the location of a decimal point or comma...
for instance, "2R2" would be 2.2 ohms, "2K2" would be 2,200 ohms,
"10M" would be 10,000,000 ohms, and so forth.

In this scheme of writing, what you *wanted* was a 100K, and what you
got was a 100R.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
On Wed, 21 Sep 2005 20:49:37 +0100, the renowned Bill <a@a.com> wrote:

Hi All,

I am an electronics newbie, so please be gentle with me! I am trying to
make up a circuit as described on a web site. All it requires is a
couple of connectors, a transistor, a resistor and a chip. It is the
resistor I am having problems with. It is supposed to be a 100K
resistor. I bought one at Maplin for the pricey sum of 9p. But I
wanted to check that it was the correct one, so I used my meter on it.
It has 5 bands: brown, black, black, black, brown. According to my
meter, on the 200 scale, it says 100. On the 200K scale it says 0.1.
surely this must not be the correct resistor (I would have expected to
see 100 on the 200K scale not 0.1). I looked at the Maplin web site
and found a picture of the resistor I bought and it says it is a 100K
resistor - at this point I got confused.
Click to expand...
Sounds like a 100.0 ohm 1% resistor. It's conceivable that the experts
at Maplin may have inadvertently given you the incorrect part.

Can someone please help me. What 5 coloured bands should I see on a
100K resistor.
Click to expand...
5% resistors-- check this out:
http://www.electrician.com/resist_calc/resist_calc.htm

(it will be brown black yellow gold)


For 100K 1% it would be brown black black orange brown

Thanks in advance to any willing helpers.

Regards
Click to expand...

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
I already replied once, but it didnt seen to appear, so apologies if
its here more than once.

Thanks to both of you that replied.

You have confirmed my suspicions that I do have the wrong resistor
(thanks! Maplin staff!). As a newbie to this sort of thing, you have
been a great help - I thank you again.

Kind regards

Bill.

(P.S. I wonder if Maplin offer any sort of compensation for blowing up
your hardware for supplying the wrong components? - I doubt it!)
 
Thanks to all who have responded,

You have confirmed that I have the wrong resistor (I thought this was
the case, but a confirmation is good). Typical Maplin staff!

I will return there tomorrow and buy another, and this time I will get
them to meter it for me and show me what it really is.

Your help is much appreciated. As a newbie to this area I need help
from people like you.

Many thanks,

Bill.



Dave Platt wrote:
In article <dgsdgi$j2f$1@news.freedom2surf.net>, Bill <a@a.com> wrote:

I am an electronics newbie, so please be gentle with me! I am trying to
make up a circuit as described on a web site. All it requires is a
couple of connectors, a transistor, a resistor and a chip. It is the
resistor I am having problems with. It is supposed to be a 100K
resistor. I bought one at Maplin for the pricey sum of 9p. But I
wanted to check that it was the correct one, so I used my meter on it.
It has 5 bands: brown, black, black, black, brown. According to my
meter, on the 200 scale, it says 100. On the 200K scale it says 0.1.
surely this must not be the correct resistor (I would have expected to
see 100 on the 200K scale not 0.1). I looked at the Maplin web site
and found a picture of the resistor I bought and it says it is a 100K
resistor - at this point I got confused.

Can someone please help me. What 5 coloured bands should I see on a
100K resistor.

See http://www.electronics-tutorials.com/basics/resistor-color-code.htm
for an explanation.

Briefly: for the digits, brown corresponds to a "1", black to a "0".
There are three digits indicating the value, one digit which indicates
the multiplier (a power-of-ten), and the final digit indicates the
precision.

What you have, it appears, is a 10001 coding, which means
(100 * 10^0), (1%) resistor. In other words, the color coding says
that it's a 100-ohm 1%-precision resistor, which matches up nicely to
what your meter is saying.

A 100K 1% resistor would be (100 * 10^3), (1%), which would be
color-coded brown-black-black-orange-brown.

A less-precise resistor such as a 5% would have only four bands, with
two digits for the value. A 100-ohm resistor of this sort would be
coded brown-black-brown-gold (10 * 10^1) (5%), and a 100k-ohm resistor
would be brown-black-yellow-gold (10 * 10^4) (5%).

In the European system of writing resistor values, it's usual to write
an "R" or "K" or "M" in the location of a decimal point or comma...
for instance, "2R2" would be 2.2 ohms, "2K2" would be 2,200 ohms,
"10M" would be 10,000,000 ohms, and so forth.

In this scheme of writing, what you *wanted* was a 100K, and what you
got was a 100R.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Click to expand...
 
Maplin experts?
"ex" is a has-been, and "spert" is a drip under pressure!

Just don't let these unskilled twerps hold both ends of the 100k resistor
whilst testing it, otherwise it will probably indicate a lot lower value.
 
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