Failure compensation circuit with thermal compensation
AssigneeAmerican Sterilizer Company
InventorsThomas E. Olon, Francis J. Zelina
Life of this patent
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Abstract
A failure compensation circuit automatically reduces the output voltage of a power supply when a portion of a load drops out. The compensation circuit includes a circuit for generating a control signal representative of the desired voltage across the load. A power supply supplies voltage to the load in response to the control signal. An input signal representative of the current delivered to the load is produced which decreases whenever a portion of the load drops out. The circuit for generating the control signal is responsive to the input signal for adjusting the control signal such that when the current delivered to the load decreases, the voltage delivered to the load is automatically reduced.
Claims16
A failure compensation circuit for automatically reducing the output voltage of a power supply when one or more lamps fail, said compensation circuit comprising:
- means for generating a control signal representative of the voltage to be supplied to the lamps;
- power supply means for supplying voltage to the lamps in response to said control signal;
- and
- means for producing an input signal representative of the current delivered to the lamps, said current decreasing in response to each lamp failure;
- said means for generating a control signal being responsive to said input signal for adjusting said control signal such that when said current decreases said voltage supplied to the lamps is automatically reduced.
A failure compensation circuit for automatically reducing the output voltage of a power supply when one or more lamps fail, said compensation circuit comprising:
- power supply means for supplying voltage to the lamps in response to a control signal;
- means for producing an input signal representative of the current delivered to the lamps, said current decreasing in response to each lamp failure.
- means for generating a reference signal representative of the desired lamp intensity;
- means for combining said input signal and said level signal
- means for combining said input signal and said level signal to produce a firing level signal;
- means for comparing said firing level signal to said reference signal for producing said control signal such that when said current decreases said firing level signal increases thereby automatically reducing the voltage delivered to the lamps.
A failure compensation circuit for automatically reducing the output voltage of a power supply when a portion of a load drops out, said compensation circuit comprising:
- means for generating an AC reference signal representative of the desired AC voltage across the load;
- means for generating a first DC firing level signal;
- means for comparing said first firing level signal to the instantaneous value of said reference signal for producing a first control signal in response to said comparison;
- power supply means for supplying AC voltage to the load in response to said first control signal;
- means for producing a DC input signal representative of the current delivered to the load, said current decreasing in response to a portion of the load dropping out;
- and
- means for adjusting said first firing level signal in response to said input signal such that when said load current decreases the voltage delivered by said power supply means is automatically reduced.
A failure compensation circuit for automatically reducing the output voltage of a power supply when a portion of a load drops out, said compensation circuit comprising:
- means for generating an AC reference signal representative of the desired AC voltage across the load;
- means for generating a first DC firing level signal;
- means for comparing said first firing level signal to the instantaneous value of said reference signal for producing a first control signal in response to said comparison;
- means for generating a second control signal representative of a minimum voltage across the load;
- power supply means for supplying AC voltage to the load in response to one of said first and second control signals;
- means for producing a DC input signal representative of the current delivered to the load, said current decreasing in response to a portion of the load dropping out;
- and
- means for adjusting said first firing level signal in response to said input signal such that when said load current decreases the voltage delivered by said power supply means is automatically reduced.
Dependencies are inferred from the claim text.