Means for transformer rectifier unit regulation
AssigneeAvionic Instruments, Inc.
InventorLewis Illingworth
Life of this patent
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Abstract
Transformer rectifier units (TRU) for the conversion of AC to regulated DC are disclosed. One aspect of a TRU according to the invention is output boost regulation by monitoring the output from a conventional TRU, and when the output drops below 28 volts DC an additional electronic switching converter boosts the output up to the 28 volt DC level. Under overload conditions a bypass diode returns the operation to that of a conventional TRU to maintain the required high current. Another aspect, input buck regulation, regulates by controlling the impedance of an auxiliary TRU by transferring its output to the DC output via a conventional flyback converter.
Claims10
A regulated power supply circuit arrangement comprising:
- a main power transformer having a delta wound primary and two secondaries, wherein first of said secondaries has a star wound configuration and second of said secondaries has a delta wound configuration;
- an auxiliary power transformer having a delta wound primary series connected with said main transformer primary and two secondaries parallel connected with said secondaries of said main transformer, wherein first of said secondaries has a star wound configuration and second of said secondaries has a delta wound configuration;
- main rectifying means coupled to said secondaries of said main transformer;
- auxiliary rectifying means coupled to said secondaries of said auxiliary transformer;
- output means coupled to said main rectifying means and said auxiliary rectifying means providing regulated DC output voltage;
- output reference means to provide a signal indicative of output voltage amplitude;
- and
- flyback means to transfer current from said auxiliary rectifying means to said output means;
- wherein said auxiliary transformer behaves as a series impedance in series with said main transformer to regulate the AC input to said main transformer.
A method of regulating an AC to DC converter, comprising the steps of:
- accepting AC current;
- providing a main transformer and an auxiliary transformer, said main transformer and said auxiliary transformer having primaries series connected, said primaries further receiving said AC current, thereafter yielding a second AC current from parallel connected secondaries of said main transformer and said auxiliary transformer, said second AC current having a voltage amplitude directly proportional to the voltage amplitude of said AC current;
- rectifying said second AC current from said secondaries of said main transformer and said auxiliary transformer to yield a DC current having a voltage amplitude directly proportional to the voltage amplitude of said second AC current;
- selectively varying the impedance of the primary of said auxiliary transformer to vary the voltage amplitude of said second AC current, thereby varying the voltage amplitude of said DC current;
- wherein said step of varying regulates the voltage amplitude of said DC current.
Dependencies are inferred from the claim text.