DMM hicupps

[scilent-project]

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.

 

[Roger]

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).

 

[Don Lancaster]

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.

There is nothing to a dc frequency.


--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Phil Allison]

"Roger" <[email protected]

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).

** What a load of *absolute* crapology.

A capacitor coupling the input signal to the meter removes any DC component
does the job.





....... Phil

 

[Brian]

Even on a very high impedance input?

 

[Phil Allison]

"Brian"


** Learn to post properly - you fucking jerk off.






......... Phil

 

[Brian]

Mad cuz wrong? Brother to Roy?

Either way, another man-child on USENET. What a surprise!

 

[Phil Allison]

"Brian"

Mad cuz wrong? Brother to Roy?

** Your meds run out did they ?

Post properly - fuckhead

At least try to make sense.







........ Phil

 

[Brian]

"Brian"

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!

 

[Phil Allison]

" Brian with no Life "


** Your meds run out did they - Brian ?


Post properly or get not more replie from me - fuckhead

At least *try* to make sense - if only for your own sake.

I know that is impossible for a raging schizoid.






........ Phil

 

[Brian]

Post properly or get not more replie from me -

....... 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!

 

[Roy L. Fuchs]

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!

Now if we could only get you to stop posting your retarded crap.

Thanks, Phil, glad you are going away. First time I ever saw you even act
close to like a man!

As if you had any clue as to what the mark was.

OK, don't reply now, keep your word, Numb Nuts!

It would be so nice to be able to reach out and thwack a fucktard
like you when you are so fucking retarded.

Phil may be an idiot troll, but you should be put against a wall and
stoned in public, boy.

 

[Phil Allison]

" 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