Change in current to change in voltage

Hi,
I'm new here and am really a programmer and just play with
hardware and electronics when I get enough free time so please be
patient with me.

I was wondering if it is possible to have a change in current and
convert it into a change in voltage, I'm interested in connecting a
thermistor
to an ADC on a microcontroller to take temperature readings, and as
thermistors change resistance dependent on temperature, and the ADC
only detects changes in voltage between a specific range I was looking
for a solution to this problem.

Thanks for your time.

 

[PeterD]

On 4 Jan 2007 08:51:00 -0800, profofeecs@hotmail.co.uk wrote:

Hi,
I'm new here and am really a programmer and just play with
hardware and electronics when I get enough free time so please be
patient with me.

I was wondering if it is possible to have a change in current and
convert it into a change in voltage, I'm interested in connecting a
thermistor
to an ADC on a microcontroller to take temperature readings, and as
thermistors change resistance dependent on temperature, and the ADC
only detects changes in voltage between a specific range I was looking
for a solution to this problem.

Thanks for your time.

Common application. Feed the thermistor with a current limited voltage
soruce (say a 33K resistor to a voltage source). Make sure the current
in the thermistor is sufficiently negligable that there is no self
heating. Then measure the voltage across the thermister.

See http://www.technologystudent.com/elec1/therm1.htm for some
suggestions. Also see
http://www.embedded.com/shared/printableArticle.jhtml?articleID=9900485
(about a third of the way down) as another example. You may be able to
drive the ADC directly with the thermistor, or you may need to add an
op amp as described.

 

[jasen]

On 2007-01-04, profofeecs@hotmail.co.uk <profofeecs@hotmail.co.uk> wrote:

Hi,
I'm new here and am really a programmer and just play with
hardware and electronics when I get enough free time so please be
patient with me.

I was wondering if it is possible to have a change in current and
convert it into a change in voltage,

you could use a resistor, they convert between voltage and current.

I'm interested in connecting a thermistor to an ADC on a microcontroller

yup use a resistor.



--

Bye.
Jasen

 

jasen wrote:

On 2007-01-04, profofeecs@hotmail.co.uk <profofeecs@hotmail.co.uk> wrote:
Hi,
I'm new here and am really a programmer and just play with
hardware and electronics when I get enough free time so please be
patient with me.

I was wondering if it is possible to have a change in current and
convert it into a change in voltage,

you could use a resistor, they convert between voltage and current.

I'm interested in connecting a thermistor to an ADC on a microcontroller

yup use a resistor.



--

Bye.
Jasen

Thanks guys that is great!