HT SUPPLIES 



constant load is presented to the rectifier circuit. Parenthetically it may 

 be remarked that the shunt stabilizer wastes the least power when the 

 device is fully loaded, whereas the series stabilizer is least wasteful when it is 

 lightly loaded. 



Set 



positive 



supply 



_r 



Set 



negative 



supply 



-300^ 



H iP 



Mams 



Figure 37.9 



The steady current drain on the negative supply produces a sufficient 

 drop across the 5k resistor to ignite the voltage reference tube, applying 

 reference potential to the left-hand side of the differential amplifier, between 



♦ 300 



100 mA max 



o 



12 El 



Stabilized ♦ve 

 supply out 



-O+550 



T 



EL8A f 



Stabilized -ve 

 supply out 



OlaF 



330k< 



-300 



50 mA max 



7S 100 k 



1/212 AT7 



Unstabilized 

 +ve supply in 



Unstabilized 

 -ve supply in 



• 550 



Figure 37.10 



591 



