Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
206 words
A series resonant power converter for avoiding temporary interruption of an operating wave form and for enabling stable control of the converter, comprising: means for oscillating the converter to provide current pulses which have a frequency of operation that define an operating wave form for the converter, said oscillating means including a first and a second resonant circuit, said first resonant circuit having a main switch means and a main transformer, said main transformer having a primary winding and a secondary winding; rectifying means for producing a direct current output power from said secondary winding of said main transformer; means for driving said main switch means from an ON-state to an OFF-state for generating said direct current output power; means for driving said main switch means to said OFF-state in response to a current flowing through said main switch means becoming zero; and means for avoiding temporary interruption of the operating wave form, said avoiding means including means for computing a voltage being applied across said main switch means and means for driving said main switch means to said ON-state in response to said voltage as computed dropping to a minimum voltage required for sustaining oscillation of the converter, whereby the converter may be stably operated.
Claim 2
Dependent Claim
206 words
A series resonant power converter for avoiding temporary interruption of an operating wave form and for enabling stable control of the converter, comprising: means for oscillating the converter to provide current pulses which have a frequency of operation that define an operating wave form for the converter, said oscillating means including a first and a second resonant circuit, said first resonant circuit having a main switch means and a main transformer, said main transformer having a primary winding and a secondary winding; rectifying means for producing a direct current output power from said secondary winding of said main transformer; means for driving said main switch means from an ON-state to an OFF-state for generating said direct current output power; means for driving said main switch means to said OFF-state in response to a current flowing through said main switch means becoming zero; and means for avoiding temporary interruption of the operating wave form, said avoiding means including means for computing a voltage being applied across said main switch means and means for driving said main switch means to said ON-state in response to said voltage as computed dropping to a minimum voltage required for sustaining oscillation of the converter, whereby the converter may be stably operated.
Claim 3
Dependent Claim
51 words
A converter as in claim 1, further comprising means for converting a direct current output voltage into an electromotive force at the primary side of said main transformer, said computing means including means for computing an input voltage, a voltage of said second resonant circuit, and said direct current output voltage.
Claim 4
Dependent Claim
240 words
A series resonant power converter according to claim 1, further comprising a first resonant circuit having said main switch means which constitutes one of a first main switch means and a second main switch means, one of which being in the ON-state, said first resonant circuit having said main transformer; a second resonant circuit; a control circuit for controlling ON-OFF operation of said first or second main switch means, wherein, said control circuit comprises driving means for driving said first or second main switch means to the OFF-state in order to generate a required DC output power; a circuit for detecting a current flowing through said one of said first and second main switch means and for driving said first or second switch means to the OFF-state at the time when the detected current becomes zero; a circuit for detecting a current flowing through said second resonant circuit and for driving one of said first and second main switch means to the OFF-state at the time when said current flowing through said second main switch means becomes zero; and a circuit having means for detecting and computing a voltage applied across one of said first and second main switch means and arranged to drive one of said first and second main switch means to the ON-state at the time when said detected and computed voltage drops to a minimum voltage required to sustain oscillation of the series resonant power converter.
Claim 5
Dependent Claim
68 words
A series resonant power converter according to claim 3, wherein said detecting and computing means comprises: a detecting circuit for detecting an input voltage; a detecting circuit for detecting a voltage of said second resonant circuit; a detecting circuit for detecting a DC output voltage converted into an electromotive force at the primary side of said main transformer; and a computing circuit for computing each of these voltages.
Claim 6
Dependent Claim
65 words
A series resonant power converter according to claim 4, further comprising: a tank circuit in series with said primary winding of said main transformer for providing an oscillating frequency; means for detecting when a current through said tank circuit is zero; and means for turning off said main switch means at a time when the current through said tank circuit is detected to be zero.
Claim 7
Dependent Claim
48 words
A series resonant power converter according to claim 4, further comprising: a load in electrical connection with said secondary winding of said transformer, said avoiding means avoiding the temporary interruption of the operating wave form even when there is a variation in said load from heavy to light.