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Review of the AADE LC Meter
-- By Jim Pearce, Pegasus Technologies
I finally have an instrument that I have wanted for many years: An LC (inductance
and capacitance) meter. Yes, my digital multimeter (DMM) has a capacitance measuring
function, but it is not really satisfactory for the very-low picofarad capacitors
that one uses every day in RF design. And, of course, the DMM has no capability
of measuring inductance. The HP — no, errrr Agilent, LCR meters are just too
expensive for occasional use.
There are some inexpensive capacitance meters out there that are slightly better
than a DMM but they still cannot measure inductance. As a result, many engineers, and practically
all hobbyists, have not had the luxury of being able to measure inductors. Before
surface mount inductors were the norm, most schematics labeled coils by the number
of turns, the size of wire and the diameter of the form since no one could measure
the beasts!
Well, I recently came across the L/C Model IIB meter made by Almost All Digital
Electronics (AADE) and after using it in the lab for a week I am in love! This meter is
quite inexpensive and simple, but amazingly accurate and useful.
The AADE L/C Meter IIB
It measures capacitors with a resolution of 0.01 pF and inductors with a 1nH
resolution. A simple push of a button cancels out the residual capacitance or
inductance of the test leads and then you are ready to make measurements.
If you make a simple jig out of a small piece of bare copper clad PC board material
you can easily measure surface mount components. I was able to measure 0402 sized
capacitors this way!
The real beauty in this meter, though, is its ability to measure inductors. Just for
fun, I measured a toroidal inductor from a junk computer power supply. The L/C Model
IIB read 5.132 uH. I then removed one turn of wire and measured again. The inductance
was now shown as 3.876 uH. Not only did I measure the inductance of an unknown coil,
but I could also find the permeability of the core.
Another neat function built into the L/C IIB is the "matching" mode. You can
use this mode to make one inductor or capacitor match the value of another one. You read
the value of the first component and then the meter reads the difference between that
value and the value of the second component. This difference is displayed either in
absolute units (pF or uH) or as a percentage.
While this meter is not traceable to NIST standards, AADE claims an average accuracy of 1%
and has test data to prove it. Considering that most components sitting on my bench have 5%
or worse tolerance, this meter can easily classify stray parts into standard values and even
differentiate them within a single standard value.
I have saved the best for the last. This meter is priced at only $129.95 in assembled and
tested form. For you students and hobbyists, a kit version is available for only $99.95, and
the complete instruction manual is available online.
Shipping and handling is a bargain at $4.00 for the US and $10.00 internationally.
You can purchase one of these by visiting AADE's website.
If you get one of these, please email me
and tell me if you like yours as much as I love mine!
Specifications of the L/C Meter IIB
Description: The L/C Meter IIB is a hand-held, digital inductance / capacitance
meter with a four digit display, featuring automatic ranging and self-calibration.
Maximum Resolution: 1 nHy / .01 pF
Range: .001 uHy (1 nHy) to 100 mHy (most units measure to 150 mHy)
.010 pf to 1 uF (most units measure to 1.5 uF), with automatic ranging
Accuracy:
1% of reading is typical (Typical means the average error of 83 different components compared to:
HP4275A digital L/C meter (test frequency 1MHz) for components ranging from .1uHy to 1mHy and 2.7pf to .068uF
B&K 878 digital LCR meter (test frequency 1KHz) for components ranging from 1mHy to 100mHy and .1uF to 1.6uF
L/C Meter II is characterized for hobby or non-critical commercial use
Self Calibrating
Error Analysis: 7/18/2000 error analysis against HP 16470A standard Inductor set
Display:
16 character LCD display module
Four digit resolution
Direct display in engineering units (ie: Lx= 1.234 uHy / Cx= 123.4 pF)
jumper option to display pF, nF, uF (ie: 10 nF instead of .01 uF)
Operating modes:
The following modes are sequentially selected
READY MEASUREnMODE - measure Lx or Cx and display in nano units when applicable
READY MEASUREuMODE - measure Lx or Cx and display in micro units (ie: .01000 uF
instead of 10.00 nF)
READY MATCHnMODE -
first measures your reference component Lz or Cz and displays it's value in nano mode
measures subsequent components, Lx or Cx, and displays the difference (Lz-Lx) or (Cz-Cx)
in nano mode
READY MATCHuMODE -
first measures your reference component Lz or Cz and displays it's value in micro mode
measures subsequent components, Lx or Cx, and displays the difference (Lz-Lx) or (Cz-Cx)
in micro mode
READY MATCH%MODE
first measures your reference component Lz or Cz and displays its value in nano units
measures subsequent components, Lx or Cx, and displays the percentage difference
(Lx-Lz)/Lz*100 or
(Cx-Cz)/Cz*100 as percent.
range is -100% to +9999%
maximum resolution is 00.01%
L/C Meter IIB zeros out stray inductance and capacitance by storing their values in RAM
and subtracting them from the measured values. It can zero out any value in it's range
allowing longer test leads and slightly improved accuracy over L/C Meter II.
L/C Meter IIB works by measuring the shift in frequency caused by inserting an unknown
into it's oscillator tank circuit. A PIC16C61 micro-controller measures the frequency
before and after. It then computes the value of the unknown using a floating point math
package and displays the result on a 16 character intelligent LCD display.
L/C Meter IIB will NOT measure inductors designed for 60 or 120 Hz applications such as
power transformers, filter chokes or motors. The minimum test frequency is about 20KHz and
these devices have enormous core losses at that frequency.
Editor's Note: We've had games on our site for years, but we're now expanding a bit and reviewing games
as well. We will put these up on our Game Reviews Page with links to the game listing
in our Games Index, but we thought we'd announce our new service here with our very
first review.
We have a panel of game testers that runs the gamut of age, gender, and gaming likes & dislikes:
Your Webmaster, a "mature" woman who loves puzzle-type games, crosswords, logic problems,
and other brain teasers;
The Director of Pegasus Technologies, a similarly mature man who enjoys relaxation games including the Lara
Croft series, but only if there is some degree of puzzle-solving involved;
a 14-year old boy who loves the electronic shoot-em-ups and has the fastest mouse finger this
side of the Mississippi; and
an 11-year old girl who likes the more quiet, contemplative type of games, especially
ones with interactive graphics.
So, if you Game Creators have a game you'd like our opinion on, please contact me
We'll give ratings from 1 to 5 stars,
along with some things we particularly liked (or disliked) about the game, our opinion on suitability for
various audiences, and contact information. Our first review is provided below:
Jigsaws Galore! Version 4
October 25, 2001
Billed as the "Ultimate Windows Jigsaw Player/Creator," Version 4 of Jigsaws Galore
has a lot to offer to the computer gaming world. There are a variety of images, and
best of all you can make any picture into a jigsaw. You can pick the shape of the
pieces, from standard to weird; pick the number of pieces, and change the 3D thickness.
The program makes a satisfying "thwock" when the pieces go together, and you have a number
of options for arranging pieces on "trays", around the edge, or in grid patterns.
Easier modes of play present the pieces in the orientation
they will go into in the puzzle; for more advanced play, the pieces can be oriented in any
direction and the program has relatively easy ways to rotate them.
This game is fun for the whole family. The display is visually appealing, with easy-to-use
tools, fun cheats (but our testers couldn't quite figure out
what the program considered as cheating), and a variety of contrasting or complementary
background colors. The background music feature was particularly appealing to our 11-year old
girl tester; I found it annoying but the default is "off" so that's not a problem.
There are only a few downsides to this game --
It can be addicting. We're having trouble getting the 11-year old to do anything else :)
The resolution, even on a fairly high-end monitor, is not as good as hard-copy puzzles for
differentiating shapes and color variations.
It would be nice if there were a two-or-more player mode.
The Upsides more than make up for these little nits. All three of our testers agreed that
Jigsaws Galore is by far the best computer puzzle game we've played, and awarded it a
five-star rating for Family Fun.
Note: We tested the full CD-ROM Gold version of this program, which comes with 192 jigsaws and
two bonus games. You can get a fully functional 30-day evaluation version with 10 jigsaws supplied directly from
Gray Design Associates (Check out his site for
other entertainment and educational programs). The game requires a Pentium Processor, 32MB RAM,
4 MB Hard Disk Space, High Color or True Color Windows Setting, a Mouse and Sound Card, and
runs on Windows 95/98/ME/NT4.0/2000.
About four months ago, SSS Online revamped our job listing pages. We now
offer a free job listing service for companies and recruiters who are looking for
technical people, managers, and support staff. We also offer a resume posting
service for people who are looking for jobs in the wireless/RF or general
electronics area. Both of these pages have attracted quite a lot of interest,
and we usually have several dozen "fresh" job postings.
Along with these new pages have come a number of questions from people who are
interested in getting a job in this industry. In one of my past lives I was a personnel
manager involved in technical recruiting for the Department of Energy for about 18 years,
so I've taken to providing some advice to people when asked (and sometimes when
it's obvious they need some help!) Below is one of the answers that may be of some
general interest, as it was from a graduating senior in college and many of our readers are
students. If you have specific questions, please send them to me at
.
Congratulations on your upcoming degree. I know how frustrating it can be
job-hunting when the job announcements all say they want 5 or more years of
experience.
Many companies have separate programs for college recruitment, and don't
do job postings for such positions. I suggest the following:
(1) register with your college placement office and interview there
(if you haven't already done that); (2) write some of the companies
that have interesting-sounding jobs, tell them you're an upcoming
fresh-out, and see if they have entry-level jobs to fill.
You might also do some things to pump up your resume, and your experience.
If you're interested in RF, I suggest you get your ham license if you don't
already have it. Many, many RF engineers are in the amateur radio hobby,
and might serve as a source of job leads as well. You might also follow
up a line of research and write a paper for publication. There are lots
of places, such as SSS Online, that would be happy to publish an interesting
article on an RF topic -- wouldn't pay you anything for it, but the
experience is good, it adds to your resume, and you get kind of a kick
seeing your words in print.
A final word -- remember that your resume will likely be screened by an
English major or other liberal-arts type person before it gets to the
technical people. Be sure to have your resume edited by a friend that's
good at wordsmithing to make sure it will pass that kind of review.
