220 V 

 > — 



30 



-> — 



Storter 

 Switch 



Voltage 

 Control 



DC. 

 Generator 



Pulse 



Frequency 



V„ Control 



_j m 



Overload -^^ ^t _, 



? I e- 



Pulse 

 Duration 

 Control 



V 



Relay 



And 



Control 



Switch 



Overlood Trip 



Pulse 

 Generator 



And 



Sequential 



Switch 





-^ 9 

 ->5 

 -^►4-8 

 -^-3-7 



^2-6 



Constant 

 Voltage 

 Tronsformer 



— > 



Calibrated 



Oscil loscope J 



Scope 



Input 



Figure 3. — Block diagrcim of electrical equipment. 



120 

 110 

 100 

 90 

 o 80 



cr 



70 

 60 

 50 

 40 

 30 

 20 



10 

 



1219 



r^ 



r^ 



— i — I — r 1 — I r — I — I — I — I 1 — I — I — I 1 — I — I — I — I r — i — r — i — i — r — i — r — i — i 1 — i 1 — n 



12 13 14 15 16 17 18 19 20 



TOTAL LENGTH IN INCHES 



10 



Figure 4. — Length frequency distribution of adult squawfish. 



