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
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