MIL-HDBK-1004/10

(2)

Stub anode circuit data:

Rectifier output = 80 V

Anode current

= 1.02 A

Anode resistance = 9.54 ohms

(3)

Variable resistor rating:

R = E/I

where

E

=

80 V

I

=

1.02/2 or 0.51 A

R

=

80/0.51

R

=

156.9 ohms

Ohmic value of resistor = 156.9 - 9.54 = 147.4 ohms

Wattage rating of resistor, (1.02) x 147.4 = 153.4 W

The nearest commercially available resistor size meeting the above

requirements is a 175-W, 200-ohm, 1-A resistor.

r) Resistance of riser anodes. In order to get the maximum

desired current in the riser (3.62 A), the resistance limit is calculated as

follows:

R = E/I

where

E

=

43.45 V

I

=

3.62 A

R

=

43.5/3.62

R

=

12.0 ohms

s)

Riser anode design:

(1) Type FW (1-1/8-inch by 9-inch) string type anodes cannot

be used in the riser because the maximum anode current discharge of 0.025 A

per anode would be exceeded. The number of type FW anodes required would be

145 and continuous throughout the riser. This is excessive. The best choice

of anode for a flexible riser string is the type G-2 (2-inch by 9-inch) high-

silicon cast iron anode.

(2)

Number of units required:

R = (0.012P log D/d)/L

L = (0.012P log D/d)R

168

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