how do I magnify a voltages in a certain range from a sensor? - Electronic Circuits Projects Diagrams Free

ghsrocketman · 23rd July 2007, 08:14 AM

okay, so the title probably didn't make sense. I wasn't sure how to explain it in such few words. anyways, here's my problem:

-I have a barometer sensor that gives off a voltage range of 0.2v-4.8v, a direct correlation to pressure (15kpa-115kpa), to an ADC (0-5v)
-Most of the data from the barometer is useless... so that I don't waste any of the ADC bits (and to get more accuracy), I'd like to chop off the voltages from 0.2-2.5v, leaving 2.5v-4.8v, and spreading that over a 0-5v spectrum...

Is this even possible?

Thanks!

ericgibbs · 23rd July 2007, 08:38 AM

hi,
I provided a a fellow rocketeer with this circuit, he had the same requirement to measure altitude/pressure.

He has built the circuit and it works OK.

It uses a AD623 opa, the Vref could be simplified if required.

Lets know if this what you have in mind.

EDIT: are you using the MPX4115A or MPX6115 sensor?

Eric

ghsrocketman · 23rd July 2007, 11:58 PM

Eric,

Thanks for the quick response. I'm using the MPX4115.

That circuit looks pretty complicated.. Is it difficult to explain?

Thanks
Matt

ericgibbs · 24th July 2007, 08:38 AM

Quote:

Originally Posted by ghsrocketman

Eric,

Thanks for the quick response. I'm using the MPX4115.

That circuit looks pretty complicated.. Is it difficult to explain?

Thanks
Matt

hi Matt,
I have attached the zipped text of some emails from/to the other rocketman.
They should answer some of your questions.

If you would like to contact the other guy, send me your email address in an email to me, I will forward it on.

Eric

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar
Title	Starter	Forum	Replies	Latest
Help with PIR Sensor	garyi	Electronic Projects Design/Ideas/Reviews	7	1st February 2007 09:44 PM
Z8 Encore Error index out of range	mootaccount	Micro Controllers	2	17th October 2006 03:23 PM
Ultrasonic range sensor	MrMikey83	Electronic Projects Design/Ideas/Reviews	2	11th February 2005 07:03 AM
Massive ERRORS in program. URGENT HELP NEEDED.	davepusey	Micro Controllers	8	18th May 2004 05:13 AM
proximity sensor : low range	ikalogic	General Electronics Chat	7	3rd April 2004 05:33 PM

23rd July 2007, 08:14 AM	#1
ghsrocketman	how do I magnify a voltages in a certain range from a sensor? okay, so the title probably didn't make sense. I wasn't sure how to explain it in such few words. anyways, here's my problem: -I have a barometer sensor that gives off a voltage range of 0.2v-4.8v, a direct correlation to pressure (15kpa-115kpa), to an ADC (0-5v) -Most of the data from the barometer is useless... so that I don't waste any of the ADC bits (and to get more accuracy), I'd like to chop off the voltages from 0.2-2.5v, leaving 2.5v-4.8v, and spreading that over a 0-5v spectrum... Is this even possible? Thanks!

23rd July 2007, 08:38 AM	#2
ericgibbs	hi, I provided a a fellow rocketeer with this circuit, he had the same requirement to measure altitude/pressure. He has built the circuit and it works OK. It uses a AD623 opa, the Vref could be simplified if required. Lets know if this what you have in mind. EDIT: are you using the MPX4115A or MPX6115 sensor? Eric Last edited by ericgibbs; 7th July 2008 at 12:21 PM.

23rd July 2007, 11:58 PM	#3
ghsrocketman	Eric, Thanks for the quick response. I'm using the MPX4115. That circuit looks pretty complicated.. Is it difficult to explain? Thanks Matt