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US 2006/0132238 A1Published application
Amplifier for inductive loads
AssigneeBAE SYSTEMS plc
InventorsScott Willis, Richard Brosh
Life of this patent
Estimating the term…
Abstract
An amplifier circuit controls the output current through an inductive load. A signal is amplified by one or more op amps, and sourced into a back to back coupling of an NPN transistor and a PNP transistor. In a positive circuit segment, current is sourced to an inductive load, and in a negative segment, current is sunk from the inductive load. The current at the output of the inductive load flows through a resistor, and the resultant voltage drop is negatively fed back to the op amp.
Claims20
An amplifier comprising:
- a first voltage source;
- a first operational amplifier coupled to said first voltage source;
- a second operational amplifier coupled to the output of said first operational amplifier;
- a first NPN transistor and a first PNP transistor coupled to an output of said second operational amplifier, said first NPN transistor and said first PNP transistor coupled back to back;
- a second PNP transistor, the base of said second PNP transistor coupled to the collector of said first NPN transistor;
- a second NPN transistor, the base of said second NPN transistor coupled to the collector of said first PNP transistor;
- a third NPN transistor, the base of said third NPN transistor coupled to the collector of said second PNP transistor;
- a third PNP transistor, the base of said third PNP transistor coupled to the collector of said second NPN transistor;
- a voice coil, wherein the emitters of said first NPN transistor, said first PNP transistor, said third NPN transistor, and said third PNP transistor are coupled to the input of said voice coil;
- and
- a resistance, said resistance coupled to the output of said voice coil and the negative input terminal of said first op amp.
8 more elements
An amplifier to control the output current of an inductive load, comprising:
- a first voltage source;
- a first operational amplifier coupled to said first voltage source;
- a second operational amplifier coupled to the output of said first operational amplifier;
- a first NPN transistor and a first PNP transistor coupled to an output of said second operational amplifier, said first NPN transistor and said first PNP transistor coupled back to back;
- a second PNP transistor, the base of said second PNP transistor coupled to the collector of said first NPN transistor;
- a second NPN transistor, the base of said second NPN transistor coupled to the collector of said first PNP transistor;
- a third NPN transistor, the base of said third NPN transistor coupled to the collector of said second PNP transistor;
- a third PNP transistor, the base of said third PNP transistor coupled to the collector of said second NPN transistor;
- an inductive load, wherein the emitters of said first NPN transistor, said first PNP transistor, said third NPN transistor, and said third PNP transistor are coupled to the input of said inductive load;
- and
- a resistance, said resistance coupled to the output of said voice coil and the negative input terminal of said first op amp.
8 more elements
An amplifier comprising:
- a first voltage source;
- an op amp coupled to said first voltage source;
- a first NPN transistor coupled back to back with a first PNP transistor, said first NPN transistor and said first PNP transistor coupled to the output of said op amp;
- a positive segment coupled to the emitter of said first NPN transistor, said positive segment comprising a second PNP transistor and a third NPN transistor;
- a negative segment coupled to the emitter of said first PNP transistor, said negative segment comprising a second NPN transistor and a third PNP transistor;
- an inductive load connected to the emitters of said third NPN transistor and said third PNP transistor;
- and
- a resistance coupled to an output of said inductive load;
- wherein said resistance is coupled to the negative input terminal of said op amp.
6 more elements
Dependencies are inferred from the claim text.