Hi can sombody explane me a bit about this subject please
as i work with a lot of sensors and control equipment i mainly use the voltage controled ones
standard is 0-10V and 0-5V so far no problems working with them and undesrstand how to manipulate and use the signal
now we do also have a 0-20mA and a 4-20mA sensors
and personaly i don't get the theory completly and do have problems how to handel these signals
these mA sensors are more used where long distance of cable is involved but you will still have a voltage drop over the cable
at the end of the line i think that the current is measured by the voltage over a resistor with a low tolerance and then handled by opamps again as a voltage signal (please educate me if it is not like this)
do I see it right that the power supply for these sensors are much more critical on the occasion of usage than the voltage sensors??
because i don't see differents in power reqirements in the sensor manuals??
while if you take the cable resistance and a given current the power suply have to vary in voltage for every different sensor conected on it unless they have all the same cable resistance
I do see circuits conected with several sensors but i don't see and don't know how they are uncoupled from each other
Thanks for any replies
Robert-Jan
as i work with a lot of sensors and control equipment i mainly use the voltage controled ones
standard is 0-10V and 0-5V so far no problems working with them and undesrstand how to manipulate and use the signal
now we do also have a 0-20mA and a 4-20mA sensors
and personaly i don't get the theory completly and do have problems how to handel these signals
these mA sensors are more used where long distance of cable is involved but you will still have a voltage drop over the cable
at the end of the line i think that the current is measured by the voltage over a resistor with a low tolerance and then handled by opamps again as a voltage signal (please educate me if it is not like this)
do I see it right that the power supply for these sensors are much more critical on the occasion of usage than the voltage sensors??
because i don't see differents in power reqirements in the sensor manuals??
while if you take the cable resistance and a given current the power suply have to vary in voltage for every different sensor conected on it unless they have all the same cable resistance
I do see circuits conected with several sensors but i don't see and don't know how they are uncoupled from each other
Thanks for any replies
Robert-Jan