Transformerless line powered digital AC voltmeter

ihsanbu · Joined: 14 Oct 2006 Posts: 27 Location: islamabad,pakistan

Hi all

I require coding help by designing the AC voltmeter using US patent
http://www.freepatentsonline.com/4908569.html

I am using the pic18f452 adc channel 0.
The input voltage range to measure the circuits in this patent are from 100vac to 500VAC and patents circuits will give voltage from 0vdc to 5vdc.

1- I require that the value measured the circuits from 0-->5vdc must be displayed on lcd/serial in form on like 220vac if the micro controller measured 3volt via adc and so on.

2- AC line power based threshold measurement and bit on/off
if input voltage is >250 the PORT C.0 become low other high.

The complete picture is here
http://imageshack.us/photo/my-images/233/acvoltmeterandpic18f452.jpg/

http://imageshack.us/photo/my-images/830/acvoltmeterandpic18f452.jpg/
regard
Thanks in advance

temtronic · Posted: Mon Aug 15, 2011 5:11 am

First be very,very careful with 'transformerless' circuits as they can EASILY KILL YOU !!! Do yourself a big favour and build using batteries or a wallwart powersupply. Once you've got the code working, THEN rewire for LIVE LINE operation.NOTHING ruins your day than to get 'zapped'.Chips are cheap, your life isn't.

that being said , there are hundreds of 'digital voltmeter projects with code on the Web just let Google help you.

once you have your code cut, send it here and we can help you 'tweak' it.

asmallri · Joined: 12 Aug 2004 Posts: 1634 Location: Perth, Australia

FvM · Joined: 27 Aug 2008 Posts: 2337 Location: Germany

newguy · Joined: 24 Jun 2004 Posts: 1904

SherpaDoug · Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA

If not for the high voltage this would be a high school science project.

[Gripe]Many times I have drawn up a design from scratch only to be told by my boss that someone has patented it and to find another way. There is never even a consideration of paying the inventor for a license.

Yes the patent system is broken and only serves to feed lawers and suppress invention. [/Gripe]
_________________
The search for better is endless. Instead simply find very good and get the job done.

asmboy · Joined: 20 Nov 2007 Posts: 2128 Location: albany ny

patent -smatent

this particular patent is soooo
EASY TO WORK AROUND - not to mention obvious -
-I HAVE TO WONDER WHY
anybody would bother to pay tribute at all.

( no matter what level of production the end result might achieve )