Chip operating temperatures

[Gordon Couger]

There are some resistors that increase resistance with temperature. I used
some for a student lab where they were controling the heat with a computer
and needed a lot of heat in a hurry but it needed to be fail safe. These
resistors will put out a fast heat pulse and never get to hot to hold. 

Gordon 

Gordon Couger Senior Software Specialist
Biosystems & Agricultural Engineering Dept.  Oklahoma State Univ.
114 Ag Hall Stillwater, OK 74075
gcouger at master.ceat.okstate.edu
>> > From:          "Mike Fahrion" <mfahrion at bb-elec.com>
>> 
>> > To take it one step further, it isn't terribly difficult to add a 
>> > heater circuit that will turn on power to a several watt resistor 
>> > when the ambient is below a certain threshold temp.  Almost always, 
>> 
>Sorry if I didn't explain myself clearly enough.  This method is used 
>to extend the cold temp range of standard commercial parts (0 
>degrees C - which can be a real problem).  The original post refered 
>to problems getting industrial spec'ed parts for the application.  
>The heater circuit turns on power to a heating resistor (usually just 
>a few watts) below a threshold temp (say 0 degrees C).  Obviously it 
>doesn't stay on indefinately - usually a bit of hysteresis is called 
>for - say shut off the power at 5 degrees C.