Difference between revisions of "Single ended - Floating"

From eDAQ Wiki
Jump to: navigation, search
 
Line 1: Line 1:
Single Ended Floating signals are signals which are not electrically connected to ground. The signal of interest appears between the two terminals of the signal source.
+
Single Ended Floating signals which are not electrically connected to ground. The signal appears between the two terminals of the signal source. This signal can either be a voltage source or a current source.
  
This signal can either be a voltage source or a current source.
+
An ideal voltage source has a near zero internal impedance - a battery for example.  A pH electrode is a voltage source but this has a very high internal resistance. An accurate reading can only be obtianed with a measuring circuit whose own internal resistance is much higher than the source resistance of the source. Voltmeters therefore need to have a high internal reistance - ideally infinite.  
  
An ideal voltage source has zero internal impedance
+
An ideal current Source has a near infinite internal impedance - a solar cell. In this case to measure the source current the measurment impedance should be very low.  Ammeters therefore need to have a low internal resistance - ideally zero. 
  
 
Here is a picture:
 
Here is a picture:
  
 
[[File:SE-Floating Source.svg|100 px]]
 
[[File:SE-Floating Source.svg|100 px]]

Latest revision as of 17:29, 13 September 2013

Single Ended Floating signals which are not electrically connected to ground. The signal appears between the two terminals of the signal source. This signal can either be a voltage source or a current source.

An ideal voltage source has a near zero internal impedance - a battery for example. A pH electrode is a voltage source but this has a very high internal resistance. An accurate reading can only be obtianed with a measuring circuit whose own internal resistance is much higher than the source resistance of the source. Voltmeters therefore need to have a high internal reistance - ideally infinite.

An ideal current Source has a near infinite internal impedance - a solar cell. In this case to measure the source current the measurment impedance should be very low. Ammeters therefore need to have a low internal resistance - ideally zero.

Here is a picture:

SE-Floating Source.svg