Load driver with integrated power factor correction
AssigneeJade Sky Technologies, Inc.
InventorsEugene L Cheung, David J Chen
Life of this patent
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Abstract
Methods and apparati for forcing the current through a load (11) in a variable DC electrical circuit to be proportional to the input voltage (V(in)). A circuit embodiment of the present invention comprises a source (27) of input AC; a rectifier (23) coupled to the input AC source (27), said rectifier (23) producing a variable DC input voltage; coupled to the rectifier (23), a load (11) having a variable direct current flowing therethrough; and means (12-16) for forcing the current through the load (11) to be proportional to the variable DC input voltage.
Claims5
A variable DC electrical circuit comprising:
- a source of input AC;
- a rectifier coupled to the input AC source, said rectifier producing a variable DC input voltage;
- coupled to the rectifier, a load having a variable direct current flowing therethrough;
- and
- means for forcing the current flowing through the load to be proportional to the variable DC input voltage, wherein the forcing means comprises:
- a variable current source coupled to the load and to the rectifier;
- coupled to the variable current source, means for sensing current flowing through the variable current source;
- coupled to the sensing means and to the rectifier, a summer;
- and
- coupled to the summer and to the variable current source, a post-summing amplifier, wherein:
- the variable current source is a three terminal device;
- the three terminal device is coupled in series with the load;
- and
- the circuit further comprises a second variable current source coupled in parallel with the load.
A variable DC electrical circuit comprising:
- a source of input AC;
- a rectifier coupled to the input AC source, said rectifier producing a variable DC input voltage;
- coupled to the rectifier, a load having a variable direct current flowing therethrough;
- and
- means for forcing the current flowing through the load to be proportional to the variable DC input voltage, wherein the forcing means comprises:
- a variable current source coupled to the load and to the rectifier;
- coupled to the variable current source, means for sensing current flowing through the variable current source;
- coupled to the sensing means and to the rectifier, a summer;
- and
- coupled to the summer and to the variable current source, a post-summing amplifier, wherein:
- the variable current source is a three terminal device coupled in series with the load;
- the sensing means samples current flowing through the three terminal device, and is coupled to a combination comprising a summer and a post-summing amplifier;
- said combination is coupled to a terminal of the three terminal device and to the rectifier;
- and
- the circuit further comprises a second variable current source coupled in parallel with the load.
A variable DC electrical circuit comprising:
- a source of input AC;
- a rectifier coupled to the input AC source, said rectifier producing a variable DC input voltage;
- coupled to the rectifier, a load having a variable direct current flowing therethrough;
- and
- means for forcing the current flowing through the load to be proportional to the variable DC input voltage, wherein the forcing means comprises:
- a variable current source coupled to the load and to the rectifier;
- coupled to the variable current source, means for sensing current flowing through the variable current source;
- coupled to the sensing means and to the rectifier, a summer;
- and
- coupled to the summer and to the variable current source, a post-summing amplifier, wherein:
- the sensing means comprises a resistor;
- a second amplifier is coupled to the resistor;
- the summer and the post-summing amplifier are embodied in a single error amplifier, said error amplifier coupled to an output of the second amplifier, to the rectifier, and to the variable current source;
- and
- the error amplifier and the second amplifier are embodied within a single integrated circuit.
Dependencies are inferred from the claim text.