small inductors...

[unclearty]

I'm working on a little boost circuit. A friend gave me a little assortment pouch of inductors that look like resistors. My problem is, I don't know how to read these! I'm using a little breadboard method. Right now I have a working circuit, but the inductor I have in the breadboard APPEARS to be orange, orange, blue, silver. From looking on-line, I'm guessing it's a 330uh inductor. Am I close?

 

[Doug Owen]

I would have expected orange, orange, brown or orange, orange, yellow. Blue makes no sense. Best to measure.

Doug Owen

 

[MrAl]

Hi there,

Yeah, i was going to ask what kind of test equipment
do you have there?

Take care,
Al

 

[unclearty]

hmmmm.... I've never had to measure an inductor. How do I measure one? It has 4 rings..they are feinitely orange...orange....appears blue..then silver.

 

[Lost_In_Beijing]

Picture borrowed from http://www.elexp.com/t_induct.htm:

Reading material:
http://www.allaboutcircuits.com/vol_1/chpt_15/3.html


Hope this helps! /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/grin.gif

 

[Lost_In_Beijing]

Sorry unclearty, I guess the chart doesn't help. No blue multiplier. According to this page you've got a 33Henry inductor.
http://tritium.fis.unb.br/Fis3Exp/fcim.csdc.com/fcimis/compid/ind/radind.html

Doesn't sound right to me for a small molded inductor.

As far as measuring goes, start reading here:
http://www.allaboutcircuits.com/vol_2/chpt_3/3.html

It may be more trouble than its worth. /ubbthreads/images/graemlins/banghead.gif

 

[unclearty]

Right..I'm guessing the 3rd ring is really brown...330uh is probably about right. Thanks!

 

[MrAl]

Hello again unclearty,

I was asking you what kind of test equipment you
have (or can borrow) so that i can propose a test
for you to perform if you like so you can tell
what inductance you have with each one.

One simple test to check the series resistance
is to simply measure the inductor with an ohmmeter.
I wouldnt be surprised to see 5 ohms or more with
the small inductors like that, but if it's used
with a small Nichia LED it works to some degree
just the same.

If you care to announce your test equipment i'll
post a test, unless you dont have any or cant get
any.

Take care,
Al

 

[carbonsparky]

Are you sure it is not a resistor? Orange, orange, blue would give you a 33Meg resistor.

 

[unclearty]

My friend said ..it is definitely an inductor. I told him about the ring colors and he also said it MUST be a 330uh.
I own a pretty good DMM..as well as a real cheapie. That's about it for testing equipment.
I'll try measuring resistance tonight when I get home.

 

[MrAl]

Oh ok great. Post the results here ok?

Take care,
Al

 

[slipstream4ph]

I think its about right, Orange orange brown gold, is about 330uH. I think these inductors are Choke inductors. Im not sure mind you. You could try this online calculator http://tritium.fis.unb.br/Fis3Exp/fcim.csdc.com/fcimis/compid/ind/radind.html. /ubbthreads/images/graemlins/thumbsup.gif

 

[unclearty]

Does anyone have a site where I could order more of these? I'm not having much luck obtaining more of this size inductor.

 

[MrAl]

Hi again,

Did you try BG Micro?

Take care,
Al

 

[Doug Owen]

[ QUOTE ]
unclearty said:
Does anyone have a site where I could order more of these? I'm not having much luck obtaining more of this size inductor.

[/ QUOTE ]

Yup. Jameco . Part number 208215 . Half a buck each at present (the prices shift over time).

Doug Owen