GM Coolant sensor

[dzorde at aesprodata.com.au]

Thanks, unfortunately the sensor is normally tied to ground when screwed into 
the block or other places of metal, so turning a NTC thermistor into a PTC 
thermistor becomes a bit of a mess, although not impossible.  I may just get a 
PTC thermistor and encapsulate it in a brass plug to produce the temp sensor.  
Quite easy, but it would still be easier to buy one.

Dan     dzorde at aesprodata.com.au 

______________________________ Reply Separator _________________________________
Subject: Re: GM Coolant sensor
Author:  diy_efi at coulomb.eng.ohio-state.edu at INTERNET
Date:    9/19/96 2:46 PM

<snip> <snip> <snip>
     
               v+                             v+             
               |                              |              
               R1                            Th1           
               |                              |            
               +----out                       +----out     
               |                              |             
              Th1                             R1              
               |                              |               
              ---                            ---              
             Fig 1                          Fig 2
     
The circuit of Fig 1 will give a decreasing voltage with increasing temp. 
However, if you reverse the positions of the resistor and the thermistor, as 
in Fig 2, you will also reverse the slope of the output voltage, and thus
have a positive slope output even though the sensor itself has a negative slope.
     
     
     
regards
dn
dnorquay at awinc.com