Sonsivri
 
Home Contact Us Help Search GoogleTagged Donations Login Register
*
Welcome, Guest. Please login or register.
Did you miss your activation email? 		November 25, 2024, 08:57:26 08:57


Login with username, password and session length


Sonsivri > Electronics > General Electronics (Moderators: o2, pickit2) > Measuring parts of a voltage
Pages: [1]
« previous next »
Print
Author Topic: Measuring parts of a voltage  (Read 3310 times)
0 Members and 1 Guest are viewing this topic.
max
Senior Member
****
Offline Offline

Posts: 321

Thank You
-Given: 1661
-Receive: 52
« on: July 04, 2010, 11:28:41 11:28 »
Hi friends,

How to measure part of a voltage with ground reference?

e.g  I want to measure voltage from 10v to 14v with ground
reference (i.e 0 - 4v ref to ground), which is varying from 0 to 20v.

Regards
Logged
Fate arrived and made the conscious unconscious It silenced the activity of life.
pickit2
Moderator
Hero Member
*****
Offline Offline

Posts: 4668

Thank You
-Given: 834
-Receive: 4322


There is no evidence that I muted SoNsIvRi
« Reply #1 on: July 04, 2010, 11:43:14 11:43 »
http://english.cxem.net/izmer/measured44.php

shows you how
Logged
Note: I stoped Muteing bad members OK I now put thier account in sleep mode
Biggles
Junior Member
**
Offline Offline

Posts: 47

Thank You
-Given: 15
-Receive: 23
« Reply #2 on: July 04, 2010, 11:46:56 11:46 »
I have never had to do this, I think your answer is in opamps to subtract voltage.. something like this... 

http://homepages.which.net/~paul.hills/Circuits/Adder/Adder.html 
Logged
Man who act in haste, repent at leisure.
bobcat1
Senior Member
****
Offline Offline

Posts: 304

Thank You
-Given: 4285
-Receive: 94
« Reply #3 on: July 10, 2010, 02:01:23 14:01 »
Hi

You need to use a resistive voltage divider using 2 resistor in series between the power source to be measured and ground

and measuring point from the resistor interaction and ground

solve the formula for R2 : Vo = VCC*R2/(R1+R2) where R1= 10K,VCC = 20V & Vo = 4V

All the best

Bobi
Logged
borberk
Senior Member
****
Offline Offline

Posts: 296

Thank You
-Given: 309
-Receive: 598
« Reply #4 on: July 10, 2010, 06:20:50 18:20 »
As I understand the problem is measuring 10-14V as 0-4V against the ground. Proposed circuit is bellow and only simulated but not tested in reality.
V1 max current is less than 30mA.
X1 subtracts 10V from input and X2 limits the output voltage on OP to 4V.
« Last Edit: July 10, 2010, 06:37:58 18:37 by borberk » Logged
Pages: [1]
Print
« previous next »
Jump to:  


DISCLAIMER
WE DONT HOST ANY ILLEGAL FILES ON THE SERVER
USE CONTACT US TO REPORT ILLEGAL FILES
ADMINISTRATORS CANNOT BE HELD RESPONSIBLE FOR USERS POSTS AND LINKS

... Copyright © 2003-2999 Sonsivri.to ...
 Powered by SMF 1.1.18 | SMF © 2006-2009, Simple Machines LLC | HarzeM Dilber MC