Sec. 3-1] 



MAGNETIC TEA XSDl 'CKRS 



201 



and (3-1)26. A sinusoidal voltage from an a-c generator is applied to 

 two probe coils Cj and C 2 . The coils contain ferromagnetic cores of a 

 material which shows high permeability and saturation at low mag- 

 netizing field strength (permalloy). The current is high enough so 



Fig. (3-1)26. Voltage-time diagram of the transducer shown in Fig. (3-1)25: 

 solid lines, without external magnetic field H ; dashed lines, with field H ; 

 (a) magnetizing field; (6) magnetization curves; (c x ) field in core c 1 ; (c 2 ) in 

 core c 2 ; (d x ) voltage induced in coil d t ; (d 2 ) in coil fl! 2 ; (e) output after 

 filtering. 



that saturation occurs. Voltages of equal magnitude but opposite 

 direction are induced in the secondary coils D x and D 2 . These volt- 

 ages are not sinusoidal and contain large percentages of the odd 

 harmonics. The coils are connected in series, so that the total output 

 is zero. If now a (small) external field H is applied in the direction of 



