EFFECT OF ELECTRICAL PARAMETERS ON YOUNG SALMON 



225 



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SECTION A-A 



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DETAIL SECTION A-A 



SCALE IN FEET 



Figure 1. — Plan and cross-sectional view of experimental channel. 



bers to support the electrodes, their connecting 

 wires, and the electrical-pulse supply cables from 

 the sequential switching equipment (fig. 5). The 

 array was suspended so that the bottoms of the 

 electrodes were Yi inch from the bottom of the 

 tank. The electrodes were 2K-foot lengths of gal- 

 vanized electrical conduit with an outside di- 

 ameter of 1.163 inches. They were arranged in 

 five staggered rows with 2-foot spaces between 

 the electrodes in each row. The upstream row of 

 electrodes was designated row A and the down- 

 streani row, row E. The spacing was 2 feet between 

 rows A and B, \]i feet between rows B and C, 1 

 foot between rows C and D, and 1 foot between 

 rows D and E (fig. 6). The appUed voltage to all 

 electrodes was the same; hence, the decreasing 

 distance between electrode rows created an area 

 of higher voltage gradient on the downstream side 

 of the array. 



Water resistivity. — Four levels of water resis- 

 tivity, 1,000, 5,000, 10,000, and 15,000 ohm centi- 

 meters, were tested. 



Pulse shape. — Tlie tests included two variations 

 of pulse shape: square-wave and half sine-wave 

 (fig. 7). 



Pulse amplitude. — Two levels of applied peak 

 voltage were tested: 165 and 250 volts. 



Pulse duration. — The pulse duration for both 

 the square-wave and the half sine-wave pulses was 

 8.3 milliseconds. 



Sequential switching equipment. — The electronic 

 equipment that supplied the square-wave pulses 

 consisted of a pulse generator that sequentially 

 switched the output of a direct current generator 

 to various groups of electrodes. The d.c. generator 

 was powered by commercially available 60-cycle 

 alternating current. Figure 8 is a block diagram 

 of this equipment. A detailed description and 

 schematic diagrams of tlie switching equipment 

 are being prepared and will be published at a later 

 date.* 



The equipment that supplied the half sine- 

 wave pulses was essentially the same as that 

 which supplied the square-wave pulses, except that 

 the d.c. generator, the overload protector, and the 

 exciter were replaced by 60-cyclc alternating 



' Volz, Charles D., and H. P. Dale. Manuscript In preparation. A hlRh- 

 powor pulse generator for electrical flsh-guldinK research. Bureau of 

 Commercial Fisheries Biological Laboratory, Seattle, Wash. 



