258 INSTRUMENTATION IN SCIENTIFIC RESEARCH [Chap. 5 



Voltage-stabilizing elements, such as gas- discharge stabilizers ( VR 

 tubes) in voltage-dividing networks, have been described by Mackay 

 and Soule 1 and by Stump and Talley. 2 The use of Zener diodes is 

 described by Flagge and Harris. 3 A circuit diagram of the Zener- 

 diode stabilized voltage divider is shown in Fig. (5-1)25. An improved 

 circuit of this type is described by Hendrick. 4 The methods do not 



2 



100 K each 



0.01 



0.0 1 



0.01 



0.01 



Fig. (5-1)24. Resistive voltage divider with parallel 

 capacitors in the last four stages [from F. H. Marshall, 

 J. W. Coltman, and A. I. Bennett, Rev. Sci. Instr., 19, 744 

 (1948); by permission]. 



/^I D2 03 Z>4 05 06 07 08 09 Ao^h 



M 



-W- 



-w- 



N " W 



"k 0.082 



<l <!0 ^9 k8.2 k.75 k6 k5 <3.3 <2.8 <1.8 <0.9 



/./ 0.63 0.63 0.72 0.75 0.82 1 



1.2 1.35 



- Unregulated d-c voltage - 



Fig. (5-1)25. Zener diode stabilized voltage divider; all 

 resistance values in megohms [from B. cVE. Flagge anal O. R. 

 Harris, Rev. Sci. Instr., 26, 619 (1955); by permission]. 



permit a variation of the partial voltages to allow for optimum 

 focusing or gain control. This drawback is overcome in a voltage 

 divider described by Kane, 5 who uses triodes as voltage-stabilizing 

 elements. The dynode voltages remain practically constant for an 

 anode current variation from zero to about 6 raA. A resistive voltage 

 divider in conjunction with an auxiliary battery which affords con- 

 siderable stabilization but reduces the gain to about one-fifth that 



1 A. S. Mackay and R. R. Soule, Electronics, 22, 101 (January, 1949). 



2 R. Stump and H. E. Talley, Rev. Sci. Instr., 25, 1132 (1954). 



3 B. d'E. Flagge and O. R. Harris, Rev. Sci. Instr., 26, 619 (1955). 



4 R. W. Hendrick, Rev. Sci. Instr., 27, 240 (1956). 



5 J. V. Kane, Rev. Sci. Instr., 28, 582 (1957). 



