BUNOEE 



-FLOAT 



-SUBSURFACE BUOY A 

 DATA LOOQNQ RACKAGE 



-UNDERWATER SENSOR UNITS 



-RELEASE DEVICE 



Fig. 1. 



STMPSON ANCHOR 



Diagrammatic illustration of complete 

 untended buoy system. 



.,***■*':* 



Fig. 2. 



Surface buoy in place during 

 first field trials. 



is located midway along the slack cable to pre- 

 vent the bite in this line from dipping below the 

 subsurface buoy. Also incorporated across this 

 bite of line is a section of bungee shock cord 

 to act as a shock mitigator on the mooring line. 

 The surface buoy has approximately 2,500 pounds 

 of buoyancy. An inverted cone was chosen because 

 of its non-capsizable properties. The shape of 

 the subsurface and surface buoys is the same 

 simply because the surface buoy mold was inex- 

 pensively usable. 



DATA ACQUISITION SYSTEM 



The data system (Fig. 3) is designed to accom- 

 modate oceanographic sensors whose outputs are a 

 variable resistance, voltage, current frequency 

 or serial pulse train. The analog input signal 

 is converted into digital form by logic processes 

 in the buoy data system (Fig. K) and then con- 

 verted into 12 bit binary form and stored on mag- 

 netic tape. The magnetic tape recorder is a 

 special type employing a static digital recording 

 technique. The master sequence clock for the 

 buoy system is developed from a transistorized 

 Brailsford DC motor with a cam that drives a 

 micro-switch to start the data cycle. There are 

 2 modes of operation; 2 minutes and 20 minutes. 

 The DC motor is driven from a 120 cps standard 

 frequency source that has been developed by 

 Marine Advisers . It consists of a 120 Kcps crys- 

 tal and several tunnel diode divider stages. The 

 120 cps frequency standard that draws 3 milli- 

 watts of power and the Brailsford motor that 

 draws approximately 300 milliwatts are the only 

 components in the system that have a 100$ duty 

 cycle. All other parts are sequence operated as 

 far as power is concerned. 



88 



