Bushing balance controller and method of using same

Claim 1

An apparatus for controlling the temperature of each section of an N section glass fiber forming bushing, comprising, in combination, N means for sensing the temperature of each section of the N section bushing, N means for developing a respective temperature control signal for said each section of the N section bushing, N power supply means for supplying current to the N section bushing one of said N power supply means supplying current to all N sections of the N section bushing in response to one of said respective temperature control signals, and N-1 of said N power supply means supplying current to N-1 respective sections of the N section bushing in response to N-1 respective temperature control signals, where N is a positive integer greater than one.

Claim 2

An apparatus for controlling the temperature of each section of an N section glass fiber forming bushing, comprising, in combination, N means for sensing the temperature of each section of the N section bushing, N means for developing a respective temperature control signal for said each section of the N section bushing, N power supply means for supplying current to the N section bushing one of said N power supply means supplying current to all N sections of the N section bushing in response to one of said respective temperature control signals, and N-1 of said N power supply means supplying current to N-1 respective sections of the N section bushing in response to N-1 respective temperature control signals, where N is a positive integer greater than one.

Claim 8

An apparatus for maintaining a constant temperature in each section of a multiple section glass fiber forming bushing comprising: (a) a glass fiber forming bushing compartmentalized into "N" individual section and constructed of a material which has a linear relationship between resistance and temperature characterized by the relationship R.sub.N =R.sub.S [+α(T.sub.N -T.sub.S)] where N=1 to total number of bushing sections R N =instantaneous resistance of a given bushing section R S =resistance of the material at the set point temperature T S α=resistivity change per degree Fahrenheit for the material used in the bushing T N =instantaneous temperature of a given bushing section T S =set point temperature of the section of the bushing (b) means to supply electrical current I B to said (c) a current transformer to produce a signal proportional to the current I B flowing in said bushing; (d) means to determine a voltage drop E N across each section of said bushing; (e) means to determine an error signal X N for each section of said bushing having the value: X.sub.N =CI.sub.B -KE.sub.N where C and K are constants, said error signal also equal to X.sub.N =KI.sub.B R.sub.S αΔT.sub.N where ΔT N =the difference between the instantaneous temperature T N of a given section of said bushing and the set point temperature T S ; (f) means to inject current into N-1 of said bushing sections in response to said respective N-1 error signals; (g) control means to regulate the supply of electrical current I B to the bushing in response to said Nth error signal; and (h) means to disable measurement of the voltage drops and current when current is being injected, and means to disable current injection when the voltage drops and current are being measured.

Claim 9

An apparatus for maintaining a constant temperature in each section of a multiple section glass fiber forming bushing comprising: (a) a glass fiber forming bushing compartmentalized into "N" individual section and constructed of a material which has a linear relationship between resistance and temperature characterized by the relationship R.sub.N =R.sub.S [+α(T.sub.N -T.sub.S)] where N=1 to total number of bushing sections R N =instantaneous resistance of a given bushing section R S =resistance of the material at the set point temperature T S α=resistivity change per degree Fahrenheit for the material used in the bushing T N =instantaneous temperature of a given bushing section T S =set point temperature of the section of the bushing (b) means to supply electrical current I B to said (c) a current transformer to produce a signal proportional to the current I B flowing in said bushing; (d) means to determine a voltage drop E N across each section of said bushing; (e) means to determine an error signal X N for each section of said bushing having the value: X.sub.N =CI.sub.B -KE.sub.N where C and K are constants, said error signal also equal to X.sub.N =KI.sub.B R.sub.S αΔT.sub.N where ΔT N =the difference between the instantaneous temperature T N of a given section of said bushing and the set point temperature T S ; (f) means to inject current into N-1 of said bushing sections in response to said respective N-1 error signals; (g) control means to regulate the supply of electrical current I B to the bushing in response to said Nth error signal; and (h) means to disable measurement of the voltage drops and current when current is being injected, and means to disable current injection when the voltage drops and current are being measured.

Claim 10

An apparatus for balancing the temperature in each section of a multiple section glass fiber forming bushing comprising: (a) means to determine a voltage drop across each section of a glass fiber forming bushing; (b) means to determine a voltage drop across said bushing; (c) means for calculating an error signal for each section of said glass fiber forming bushing based upon he voltage drop across the section and the current flowing in the section; (d) means for injecting current into all but one of said sections in accordance with a respective all but one of said error signals; and (e) means for supplying current to said bushing in accordance with the remaining error signal

Claim 11

An apparatus for balancing the temperature in each section of a multiple section glass fiber forming bushing comprising: (a) means to determine a voltage drop across each section of a glass fiber forming bushing; (b) means to determine a voltage drop across said bushing; (c) means for calculating an error signal for each section of said glass fiber forming bushing based upon he voltage drop across the section and the current flowing in the section; (d) means for injecting current into all but one of said sections in accordance with a respective all but one of said error signals; and (e) means for supplying current to said bushing in accordance with the remaining error signal

Claim 14

A method of balancing the temperature in each section of an N section glass fiber forming bushing, comprising the steps of: measuring the temperature of each section of the N section bushing, developing a respective temperature control signal for said each section of the N section bushing, supplying current to all N sections of the N section bushing in response to one of said respective temperature control signals, and supplying current to N-1 respective sections of the N section bushing in response to N-1 of said respective temeprature control signals, where N is a positive integer greater than one.

Claim 15

A method of balancing the temperature in each section of an N section glass fiber forming bushing, comprising the steps of: measuring the temperature of each section of the N section bushing, developing a respective temperature control signal for said each section of the N section bushing, supplying current to all N sections of the N section bushing in response to one of said respective temperature control signals, and supplying current to N-1 respective sections of the N section bushing in response to N-1 of said respective temeprature control signals, where N is a positive integer greater than one.