Converter circuit having a controlled output

Claim 2

A converter circuit comprising: a tuned resonant circuit, switching means for periodically energizing said tuned circuit from a direct current source for producing an alternating current in said tuned circuit, means coupled to said tuned circuit for receiving an output in response to alternating current produced in said tuned circuit, feedback means for causing said switching means to switch substantially at a rate synchronized with a resonant frequency of said tuned circuit, and means for altering said switching rate in response to the output level of said means for receiving an output, wherein said means for altering the switching rate is responsive near substantially zero current conditions in the tuned resonant circuit and said switching means for disabling said feedback means for a selected period of time during each cycle operation dependent on the output level of said circuit.

Claim 3

The circuit according to claim 1 wherein said means for receiving an output comprises rectifier means coupled to said tuned circuit for producing direct current output, said rectifier means producing the output level to which said means for altering the switching rate is responsive.

Claim 4

A converter circuit comprising: direct current input terminals, a tuned resonant circuit comprising an inductance and a capacitance in series therewith, an output transformer having a primary winding thereon, one end of which is coupled to said series resonant circuit and the other end of which is coupled to a first direct current input terminal, a first switching means for coupling the remaining direct current input terminal to said resonant circuit, a second switching means for coupling the first direct current input terminal to said resonant circuit, synchronizing means for detecting the waveform in said resonant circuit for alternately operating said switching means, said synchronizing means switching said switching means under nearly zero current flow conditions between said switching means and said resonant circuit, and control means for detecting the output level in said output transformer for rendering said synchronizing means ineffective for a predeteRmined period of time during each cycle of operation thereof dependent on the output level of said transformer.

Claim 5

A converter circuit comprising: direct current input terminals, a tuned resonant circuit comprising an inductance and a capacitance in series therewith, an output transformer having a primary winding thereon, one end of which is coupled to said series resonant circuit and the other end of which is coupled to a first direct current input terminal, a first switching means for coupling the remaining direct current input terminal to said resonant circuit, a second switching means for coupling the first direct current input terminal to said resonant circuit, synchronizing means for detecting the waveform in said resonant circuit for alternately operating said switching means, said synchronizing means switching said switching means under nearly zero current flow conditions between said switching means and said resonant circuit, and control means for detecting the output level in said output transformer for rendering said synchronizing means ineffective for a predeteRmined period of time during each cycle of operation thereof dependent on the output level of said transformer.

Claim 6

The circuit according to claim 3 wherein said switching means comprise transistors.

Claim 7

The circuit according to claim 3 wherein said output transformer has at least one secondary winding and a direct current load, and further including rectifier means between said winding and said load.

Claim 8

The circuit according to claim 3 wherein said control means is provided with coupling means for sensing the waveform in said resonant circuit, means for providing a level responsive to predetermined values of output from said transformer, and means for disabling said synchronization for predetermined periods of time at times detected by said coupling means and in response to said level.

Claim 9

The circuit according to claim 3 wherein said switching means comprise transistors alternately coupling said resonant circuit with said output transformer, said synchronization means including a transformer having a primary thereon connected in series with said resonant circuit, and secondary windings on said last mentioned transformer coupled with control electrodes of transistors for causing said transistors to conduct alternately in accordance with the polarity of the waveform in said resonant circuit.

Claim 10

The circuit according to claim 7 wherein said control means includes an additional transformer having a primary winding coupled in series with said resonant circuit, said control means further including a monostable multivibrator for producing a pulse in response to the approximate zero crossing of the AC wave in said resonant circuit, and an additional winding on said synchronizing means transformer for receiving the output of said monostable multivibrator and inhibiting the operation of said transistors for the period of operation of said monostable multivibrator, said monostable multivibrator having a timing circuit responsive to the output voltage level of said converter circuit so that said transistors are turned off for a period of time each cycle dependent upon the output level of said converter circuit.

Claim 11

The circuit according to claim 8 further including diodes shunted across each of said transistors in a reverse polarity direction from the principal current carrying paths of said transistors.

Claim 12

A circuit for producing an alternating current in response to a direct current supply, comprising: an active controlled device and resonant frequency determining means in circuit with said active controlled device, means providing positive feedback from an output of said active controlled device to an input thereof, causing said active controlled device to tend to oscillate and produce an alternating output at substantially the resonant frequency of said resonant frequency determining means, and means responsive to the level of output of said circuit for determining the time during each cycle when said feedback is applied by effectively decoupling said feedback for a selected time period during each cycle of said alternating output, depending upon said output level.

Claim 13

A circuit for producing an alternating current in response to a direct current supply, comprising: an active controlled device and resonant frequency determining means in circuit with said active controlled device, means providing positive feedback from an output of said active controlled device to an input thereof, causing said active controlled device to tend to oscillate and produce an alternating output at substantially the resonant frequency of said resonant frequency determining means, and means responsive to the level of output of said circuit for determining the time during each cycle when said feedback is applied by effectively decoupling said feedback for a selected time period during each cycle of said alternating output, depending upon said output level.

Claim 14

The circuit according to claim 10 wherein said responsive means includes switching means for switching said feedback during each cycle.

Claim 15

The circuit according to claim 10 wherein said active controlled device comprises switching means, and wherein said responsive means switches said switching means into an operative condition for only a selected time period during each cycle of alternating output dependent upon the output level.

Claim 16

The circuit according to claim 12 wherein said switching means is operated under substantially low current conditions.

Claim 17

A converter circuit comprising: a tuned resonant circuit, switching means for periodically energizing said tuned circuit from a direct current source for producing an alternating current in said tuned circuit, means coupled to said tuned circuit for receiving an output in response To alternating current produced in said tuned circuit, wherein said switching means comprises first and second transistors alternately coupling said tuned circuit to the means for receiving an output, a first of said transistors being serially interposed between said tuned circuit and one terminal of the direct current source with the second of said transistors being coupled between said tuned circuit and the other terminal of the same direct current source, feedback means for causing said switching means to switch substantially at a rate synchronized with a resonant frequency of said tuned circuit, and means for altering said switching rate in response to the output level of said means for receiving an output.

Claim 18

A converter circuit comprising: a tuned resonant circuit, switching means for periodically energizing said tuned circuit from a direct current source for producing an alternating current in said tuned circuit, means coupled to said tuned circuit for receiving an output in response To alternating current produced in said tuned circuit, wherein said switching means comprises first and second transistors alternately coupling said tuned circuit to the means for receiving an output, a first of said transistors being serially interposed between said tuned circuit and one terminal of the direct current source with the second of said transistors being coupled between said tuned circuit and the other terminal of the same direct current source, feedback means for causing said switching means to switch substantially at a rate synchronized with a resonant frequency of said tuned circuit, and means for altering said switching rate in response to the output level of said means for receiving an output.