Hi
I just want buy a digital multi meter(standarded) which is capable of measuring frequency in Hz. but some DMM says it can display both AC and DC values. I wonder what is this DC frequency anyway. And on that respect what kind of things i must check in a DMM ?
Any ideas ?
thanks in advance.
AC frequency measurement uses a comparator that measures zero volt crossings. DC signals never go negative, so if you wanted to e.g. measure the output frequency of 555 it would read zero. Measuring DC frequency involves either a) measuring the crossing at a threshold level (for example 2.5V in 5V logic circuits, or just a logic gate (ST) buffer) or b) using a diffrentiator circuit (which could be nothing more esoteric than a biased RC network).
There is nothing to a dc frequency.
** What a load of *absolute* crapology.
A capacitor coupling the input signal to the meter removes any DC component does the job.
...... Phil
Even on a very high impedance input?
"Brian"
** Learn to post properly - you f****ng jerk off......... Phil
Mad cuz wrong? Brother to Roy?
Either way, another man-child on USENET. What a surprise!
"Brian"
** Your meds run out did they ?Post properly - f*****ad
At least try to make sense.
....... Phil
Some get expensive cars. Others get motorcycles. And some post profanity on USENET.
ALL suffer from the same thing: small size of their manhood.
Next time, try Enzyte!
" Brian with no Life "
** Your meds run out did they - Brian ?Post properly or get not more replie from me - f*****ad
At least *try* to make sense - if only for your own sake.
I know that is impossible for a raging schizoid.
....... Phil
Do you mean it? That would be GRAND! I don't need any more stupid replies from people like you. Really, I won't miss them!
Thanks, Phil, glad you are going away. First time I ever saw you even act close to like a man!
OK, don't reply now, keep your word, Numb Nuts!
On Sat, 10 Jun 2006 13:30:17 -0500, "Brian" Gave us:
Now if we could only get you to stop posting your retarded crap.
As if you had any clue as to what the mark was.
It would be so nice to be able to reach out and thwack a fucktard like you when you are so f****ng retarded.
Phil may be an idiot troll, but you should be put against a wall and stoned in public, boy.
" Brian with no Life "
** Your meds run out did they - Brian ?At least *try* to make sense - if only for your own sake.
I know that is impossible for a raging schizoid.
....... Phil
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