Well for anyone following an old thread here's someone who actually did the classic PIC LC meter using the internal comparators on a 16F628 **broken link removed** **broken link removed**
I haven't been back to visit that site in some time so it's a nice surprise to find Mr. Rice has updated it with a single-chip LC Meter solution, something that you and I have been interested in for awhile now...
as per the spec superprobe,
"When an inductor is connected from the tip to the ground lead, and button #1 is pushed, its value is displayed. Values from 0.1 to 999.9 millihenries are displayed. "
it can resolve .1mH
while the other one under concern can measure 10nH minimum-- while the original design of AADE.com can resolve .1nH
I would rather see an LCD with 15 or 20 characters.
It would allow real text instead of cryptic 7 segment labels
Also you could display Hz KHz and MHz instead of: no decimal for Hz, flashing decimal for KHz, and solid decimal for MHz. Or maybe it was flashing for MHz...
I have in my hand the same meter (more or less). Mine is old and I see there is a new version now. I also have a very big $$$ HP LCR meter that I do not use because this little meter is as good in most cases. It really works well at 1pF or to measure the inductance of 3" of wire. This meter will not work with BIG ele. capacitors. Almost All Digital Electronics
I have in my hand the same meter (more or less). Mine is old and I see there is a new version now. I also have a very big $$$ HP LCR meter that I do not use because this little meter is as good in most cases. It really works well at 1pF or to measure the inductance of 3" of wire. This meter will not work with BIG ele. capacitors. Almost All Digital Electronics
I have in my hand the same meter (more or less). Mine is old and I see there is a new version now. I also have a very big $$$ HP LCR meter that I do not use because this little meter is as good in most cases. It really works well at 1pF or to measure the inductance of 3" of wire. This meter will not work with BIG ele. capacitors. Almost All Digital Electronics
It seems to be the math, the LC tank still oscillates just fine with monster inductors but the calculations are out of range.
Would be fun to try a dsPIC on the design, it's overkill but the math should be much easier to implement. Plus it should be easy to code in some additional features like a simple function generator etc...
Mine shows overrange after calibration screen.......can you find some possible causes::
and, my poor meter have a 450uH inductor in place of 82~100uH....which simply can't generate the expected tank oscillation frequency.....will changing it blow the overrange error away?
I've no 5V relay...but i'm looking about to buy a such from farnell.in .....I've connected a 2N7000 as me friend eblc showed...i think it's corrcet...
Mine shows overrange after calibration screen.......can you find some possible causes::
and, my poor meter have a 450uH inductor in place of 82~100uH....which simply can't generate the expected tank oscillation frequency.....will changing it blow the overrange error away?
I've no 5V relay...but i'm looking about to buy a such from farnell.in .....I've connected a 2N7000 as me friend eblc showed...i think it's corrcet...
450uH is far too high perhaps. 100uH &5V relay are generally available.
There are single line and DIP relays made by either OEN or PLA. One can retrieve a relay from any dial up modem cards. we may use a drive transistor and directly use 12V instead of 5V regulated by 78L05.