DMM information sought

[Rob Flinn]

Hi folks does anyone have a web link for a site that explains how a DMM works. i.e flow diagram of the architecture & explaination of the function of it with regards to Vref Memory DAC etc ?

Would be very grateful if anyone can help me.

 

[CJ]

Everything is on one chip nowdays, but I guess you could analyze the chip.

 

[Rob Flinn]

Thanks CJ, but I`ve got to research for a report I`ve got to write. I`d rather spend my time DIYing, but I`ve got no choice.

 

[Kev]

??
:?

Rob,
a report is one thing but why the DMM details ...
what are you up to ?

 

[Rob Flinn]

Its a report I`vegot to write for a ollege assignment.

 

[Mark Burnley]

Rob,

I may have an old electronics mag with something useful in, BUT, I'm away from my vintage mag stash for at least a week...

Let me know...

Mark

 

[Rob Flinn]

Thanks Mark

If I`m still stuck in a week I`ll get back to you !

 

[Kev]

[quote author="Rob Flinn"]Its a report I`vegot to write for a ollege assignment.[/quote]
:sad:
err yeah ...

open your meter ... look at the chips and go find the application notes

google
how does a digital volt meter work
:shock:
http://users.otenet.gr/~athsam/digital_volt_and_ambere_meter_eng.htm

any use at all ?

 

[gyraf]

Most DMM's work by a dual-slope ADC, where you charge a capacitor with a constant current untill a comparator sees that the charged voltage is the same as your to-be-measured input voltage. In the mean time you have a timer-counter that keeps track on how long you charged the cap. This count equals your input voltage.

Jakob E.

 

[Rob Flinn]

Thanks guys

Thats getting more in the right direction.

Kev, I tried doing a google search for DMM/digital meter etc but couldn`t get anything but sales pitches or how to use one. Anyhow thanks for that.

 

[Mark Burnley]

Rob,

Check out some of the IC datasheets on this page (scroll down about half way- DMM all-in-one IC's)

Maybe of some help?

Mark

 

[Rob Flinn]

Thanks again Mark