APPENDIX V 

 DIODE EQUATIONS 



FROM LLEWELLYN AND PETERSON 



These apply to electrons injected into a space between two planes a and 

 b normal to the .v direction. Plan b is in the +.v direction from plane a. 

 Current density I and convection current q are positive in the — x direction. 

 The d-c velocities «a , «& and the a-c velocities Va , Vb are in the +.v direction. 

 T is the transit time. The notation in this appendix should not be con- 

 fused with that used in other parts of this book. It was felt that it would 

 be confusing to change the notation in Llewellyn's and Peterson's^ well- 

 known equations. 



Table I 



Electro>^ics Equations 



Numerics Employed: 



r, = 10' - = 1.77 X 10^', e - l/(367r X W) '' = 2 X 10-'' 

 m € 



Direct-Current Equations: 



Potential- velocity: tjVd ^ {l/2)u- (1) 



Space-charge-factor definition: f = 3(1 — To/T)) 



Distance: x = (1 - ^/3)(ua + Ua)T/2 > (2) 



Current density: {y}/t)lD = {ua + Ub)2^/T'' J 



Space-charge ratio: lo/Im = (9/4)f(l - f/3)- (3) 



Limiting-current density: 



r _ 2.33 iVna + Vv^bY (,. 



" " 10« X' ~ ^^^ 



Alternating-Current Equations: 

 Symbols employed : 



= ie, d = o}T, i = V^ 



1 F. B. Llewellyn and L. C. Peterson "Vacuum Tube Networks," Proc. I./i.E., vol 32. 

 pp. 144-166, March, 1944. 



444 



