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APPENDIX V 
Electric Power for Schooner RELIANCE 
by J. P. Slifko 
Both a=c and d=c sources of powor in 115 v and 120 v respectively were 
used aboard the schooner RELIANCE. The d-e source consisted of 20 6-v auto- 
mobile storage batteries of about 120 amp hr rating. This source was used 
on a 0.75 KVA inverter which supplied quite steady a~c current at 115 v for 
DuMont oscilloscopes. The d-c source was also used on the ship's lights 
when an a=-c source was not available. 
The model 50 AAl Delco generator aboard the schooner supplied 5 KVA at 
115 v, single phase, 60 c/sec. When the RELIANCE was tied at the dock, 
either 60 c/sec, 115-v, single-phase power from the Cape and Vineyard Electric 
Company, or the above mentioned Delco power, was used as an a=c source. 
Since the voltage regulation for the Delco plant was poor, no loads were 
switched during calibration and shooting. Furthermore, gasoline for the 
Delco=plant engine was filtered twice to insure a steady flow of gasoline 
free from impurities and water into the carburctor. 
To further insure steady a-c voltage for the RELIANCE electronic gear, 
a Sorensen model 1750 automatic voltage regulator was used. The manufacturer 
claimed a 0.2 percent automatic voltage regulation for a pre-set voltage 
independent of variations in input voltage, power factor, load or frequency, 
providing input voltage is between 95 and 130 v at 50 to 60 c/sec and load 
was between 800 and 2000 v ampe They also claimed stability and a complete 
recovery of voltage within from 1 to 6 cycles depending upon the magnitude 
of the voltage change. 
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