The currents Ga Z » and be may be written, 
5 tig eels 
Rr Sas 
a 
_f, + #, 
O) > Paap oY 
b 
_£, + #2 
@ Lean ee) 
C 
Substituting these expressions into eq. (B9), 
Ey ar le a, By + Bs = 2(Fy + F) =0 (B13) 
Aiea ie ae iP PP 
a Cc ) 
and since Z, + E,# 0 
il 1 2 
ewe ae ei ead (BE) 
7 R iy we 
Solving eq. (B14) for r 
an A Se i ete 
—_————————— 
OAR Sie atl (BHD) 
Dia eaae GG) 
This expression, therefore, defines the value of series resistor, 
r, for linearity in terms of the thermistor resistance in an asym- 
metric half-bridge circuit. This is the same expression as ob- 
tained by Burke for the optimum series resistor with a thermistor 
in a Wheatstone bridge. 
From eq. (B15) it is seen that if the thermistor becomes 
more linear with temperature, the denominator approaches zero, 
and the value of ” approaches infinity. Also, for a given thermis- 
tor, as the desired temperature range is decreased the value of r 
47 
