Power Line Interference - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Electrical
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 09-15-2006, 04:52 PM
Registered User
Join Date: Sep 2006
Location: singapore
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Power Line Interference


I am building my amplifier circuit for ecg and examining it

by using an oscilloscope. The circuit consists of instrumentation

amplifier(gain = 10), high pass filter(0.5Hz, gain = 3)and

low pass filter(150 Hz, gain = 35). The voltage is regulated at 5V.

Without feeding any input to the amplifier, I get the square wave

(or attenuated sine wave) with frequency 50Hz and peak-peak voltage

= 8V on oscilloscope. Is it really due to the power line

interference and why the noise has such a large amplitude?? Will it

affect my ecg signal?? and how to eliminate it? Thank you for

reading my post and hope that you can clear my doubt.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 09-16-2006, 12:42 AM
docvette's Avatar
Registered User
Last wiki edit: Rebuild an alternator Last photo:
Join Date: Mar 2004
Location: Lafayette, california
Age: 65
Posts: 7,360
Wiki Edits: 12

Thanks: 0
Thanked 7 Times in 4 Posts
Doc here,

Are you doing this HERE (USA ) or Singapore?

Here, the power company's are beginning to send DATA over the power lines..is why I ask..and in Singapore,have been doing it for some time:

Powerline around the world

There are currently two main technology providers Switzerland's Ascom and Israel's Main.net PLC. Between them, they have helped to start PLC services in many countries including Germany, Sweden, Singapore and even the remote ski-resort cities in the Austrian Tyrolean mountains. In Singapore, the incumbent utility company Singapore Power (SP) started technical trials last November, using a test-site at the Singapore Polytechnic. Initial speeds of 800 Kbps and later 2.25 Mbps were achieved. Complete Text

To isolate the cause, run your circuit on a Dedicated DC source only..and move as far away from power lines as the bench will allow..you can also "Sniff" the air with an AM radio on dead air..and listen for the oscillation.


Last edited by docvette; 09-16-2006 at 04:35 AM. Reason: added info
Reply With Quote Quick reply to this message

Recent Electrical posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
power steering won't return to center powerrodsmike Suspension - Brakes - Steering 32 10-12-2006 08:22 AM
No Power 4 BOLTS Electrical 4 01-16-2006 11:27 PM
Advise on Porta Power choice meanroy Body - Exterior 7 06-23-2004 11:38 PM
Unusual Power Steering Conversion Lars Sorensen Suspension - Brakes - Steering 17 05-25-2004 02:05 PM
68 power steering burner Suspension - Brakes - Steering 5 04-06-2004 08:20 PM

All times are GMT -6. The time now is 02:36 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.