Gee, you sure are predictable, and boring. Isn't it about time for you to morph, again? You are as useless as Spurious Response, and rapidly approaching the level of Phil Allison. No sit up and beg!
You know as little about the need for oral surgery as you do ESR meter design.
The score is zero for you, and one infected tooth cut out for me, loser.
To quote some USENET loser:
'Guess the enthusiasm fizzled when you got into the nitty-gritty of it all...'
'Guess the enthusiasm fizzled when you got into the nitty-gritty of it all...'
I can see it now, when the nursing home staff shoves you and your beat up old wheelchair outside, into a freezing rain, then they'll call the cops a couple days later to report you missing. They'll find you in the spring, or what's left of you.
'Guess the enthusiasm fizzled when you got into the nitty-gritty of it all...'
What good is it doing for you? You need all the help you can get.
You asked, and I answered. I can't help it if you don't have the guts to deal with it.
'Guess the enthusiasm fizzled when you got into the nitty-gritty of it all...'
Designing electronics requires a balanced blend of arrogance and paranoia, in addition to the obvious technical skills. Many people who can "do the math" can't design, because their personalities sabotage them.
John
I was hoping for 5% or better accuracy, so I specified sine-wave excitation because ESR does vary with frequency and with a fixed sine-wave frequency the results can be compared to measurements using one of HP's laboratory LCR meters. Furthermore, for ESR down to 1-milliohm, and modest currents, like 10mA, the signal is only 10uV. This would be a problem for a time-based A/D approach, but it's no problem at all for a synchronous detector (i.e. a lock-in amp), with 200 m-sec or so averaging.
Okay, that's a wrap. We have WH's entry. Now if only Larkin and Napoleon can learn ASCII drawing, that's soooooo tough...
I dunno, why? I have amassed quite a collection of circuits not normally used for this purpose. You could at least be creative as you ply your ugly ideas, but you're not even that...
You need to get a handle on your situation, both in real life and on newsgroup. You're suffering from a multitude of serious problems: arrested development, ignorance, denial, self-pity, anger, social rejection, loneliness, serious ill-health, to name a few. You have no quality of life, you're delusional.
I just recently beat a severe tooth infection that came out of nowhere, it went into the jaw and throat, affecting the swallow reflex detrimentally, and up the other direction into my eye. I held off taking any antibiotics and increased my dose of NuBound. I am convinced it is the NuBound that turned it around, no infection whatsoever now. I had a similar experience this past winter when the NuBound helped me kick a flu in one day, I became uncharacteristically feverish a few hours after I dosed with it, a sign of strong immune response. The fever subsided and no flu the next day.
I've done two, Win has done one (block level)... let's see Fred's now.
John
with
Hot air. Show us some electronics.
John
Yes the ESR does change with frequency but the curve isn't super sharp and the demodulating waveforms can be low in harmonics. If you go with an ADC and a micro, the demodulation can be very low in harmonics with a little work.
If you don't go with the ADC, perhaps making a driving waveform with no 5th and a multiplying one with no 3rd may be good enough. I just ate so I feel much to lazy right now to do the math on this but it sounds reasonable.
Most of the new lockins use a DSP, but I was actually thinking in terms of an analog circuit not an ADC. Using a 4053, you can get the
0,1,0,-1 pattern of gains. The inhibit input would give you the zero. A 4052 would also work and may be better because you don't end up with an open circuit.
The only thing that I'm delusional about is that your life is worth anything, to anyone.
Where is your design? You keep damming John's and Jim's work, so show us your great schematic, Mr. 'Guess the enthusiasm fizzled when you got into the nitty-gritty of it all...'.
As 'Mr T' would say, "I pity the fool who calls himself Fred Bloggs".
I deny that you are a smart as you think you are.
You can keep all your other problems to yourself. loser.
Yes you are right to leave it open, particularly since it now seems to be a bipolar (5-0-5) supply. That's much more comfortable for the analogue swings, and allows CMOS logic to be powered off a 10V supply.
with
Nope, not hot air. Why would I go the synchronous detection route when everyone else said that was their method of choice from the start. There is at least one other way to get the same sensitivity without it, and it's in wide use. Too bad you won't find out what it is from me:-)LOL
If the driving source is a voltage, current limited by a series resistor, maybe 50R, with controlled rise and fall times during the "0" gain portions, then the ESL and op-amps slew rate effects will be greatly reduced. Let's say 100KHz, 5V with 1.5uS rise and fall times. Now do your 1,0,-1,0 trick, add gain and filtering and feed to ADC. Sounds like a 800KHz osc divided by a flip flop to 400KHz and both FF outputs divided to 100KHz to get the driving and demodulating signals. Harry
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