Figure 8. — Freshwater Fish Electro-Motivator (FFEM) 

 power supply. 



double set point meter will detect current which 

 is either above or below normal limits and trip 

 an alarm of either red or amber lamps 

 respectively. Other pilot lamps indicate when 

 the main power is on and when the low voltage 

 is on. 



Summary of Field Testing 



The FFEM system was tested for reliability in 

 21 10-min fishing drags and 22 15-min voltage 

 plotting drags aboard the RV Kaho in the Sagi- 

 naw Bay area of Lake Huron. Ellis and Pickering 

 (in press) give a complete discussion of an exper- 

 iment involving the use of this gear and allied 



ICATHOOe eiEMENTS 



Figure 9. — Diagram of electrical trawl showing 

 arrangement of electrode arrays in mouth of net. 



equipment. During the field testing, the maxi- 

 mum power output was limited to 90 v DC due 

 to an anomalous electronic signal in the pulse 

 generator which shut the power supply down 

 when this limit was exceeded. However, this 

 signal presented no problem in our test. 



A 21.3-m (headrope) wing trawl, rigged with 

 an electrode array as shown in Figure 9, was 

 used. The spacing between arrays was 1.5 m and 

 between electrode array elements was 0.3 m. 



We experienced no problems with the FFEM 

 during the voltage plotting. We had a heterogen- 

 eous electrical field which ranged from 21.1 v 

 within 38.1 cm of the cathode array to 1.0 v 

 midway and then rose to 16.9 v within 38.1 cm 

 of anode array. The FFEM did shut down at the 

 end of the 21st fishing drag probably due to the 

 electronic anomaly which we knew was present. 

 The catch rate in kilograms of the trawl with 

 power on was 1.65 times or 65.6% more than 

 the catch rate in kilograms with power off. 



DISCUSSION 



The prototype FFEM system fully utilizes 

 electrical currents for obtaining maximum 

 power outputs at optimum pulse characteristics. 

 The system permits multiple time-sequenced 

 loads (from 1 to 4), varying pulse patterns and 

 duty cycles, varying load distribution patterns, 

 and variable output voltages and operates over a 

 wide dynamic load range. Its versatility as a 

 research tool is almost endless; however, it must 



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