High efficiency power converter
A power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier. First and second primary switches in series with first and second primary windings, respectively, are turned on for a fixed duty cycle, each for approximately one half of the switching cycle. Switched transition times are short relative to the on-state and off-state times of the controlled rectifiers. The control inputs to the controlled rectifiers are cross-coupled from opposite secondary transformer windings.
1. A dc-dc converter system comprising:
isolation/semi-regulation circuitry comprising:
a primary transformer winding circuit having at least one primary winding;
a secondary transformer winding circuit having at least one secondary winding coupled to at least one primary winding and having plural controlled rectifiers, each having a parallel uncontrolled rectifier; and
a control circuit that senses a voltage in the primary transformer winding circuit to provide a feedback control signal without bridging an isolation barrier between the primary and secondary transformer winding circuits, the feedback control signal controlling semi-regulation by control of duty cycle of a transistor in the primary transformer winding circuit; and
an output of the isolation/semi-regulation circuitry whose voltage value drops due to impedance of an output path; and
a plurality of non-isolating switching regulators, each receiving the output of the isolation/semi-regulation circuitry whose voltage value drops.
2. A dc/dc converter system as claimed in claim 1 wherein a switch in each of a plurality of the switching regulators is a controlled rectifier.
3. A dc/dc converter system as claimed in claim 1 wherein the controlled rectifiers are voltage controlled field effect transistors.
4. A dc/dc power converter system as claimed in claim 1 wherein signals controlling the controlled rectifiers are provided by the at least one secondary winding.
5. A dc/dc converter system as claimed in claim 1 wherein a signal controlling a controlled rectifier is derived from the at least one secondary winding with a capacitive divider circuit.
6. A dc/dc converter system as claimed in claim 5 further comprising a circuit to determine the dc component of the signal controlling a controlled rectifier.
7. A dc/dc converter system as claimed in claim 1 wherein each controlled rectifier is turned on and off by a signal applied to a control terminal relative to a reference terminal of the controlled rectifier and the reference terminals of the controlled rectifiers are connected to a common node.
8. A dc/dc converter system as claimed in claim 1 wherein the output of the regulation/isolation circuitry is about 12 volts.
9. A dc/dc converter system as claimed in claim 8 wherein the outputs of a plurality of the switching regulators are of voltage levels to drive logic circuitry.
10. A dc/dc converter system as claimed in claim 1 wherein the outputs of a plurality of the switching regulators are of voltage levels to drive logic circuitry.
11. A dc/dc converter system as claimed in claim 10 wherein an output of a switching regulator is about 5 volts or less.
12. A dc/dc converter system as claimed in claim 10 wherein an output of a switching regulator is about 3.3 volts.
13. A dc/dc converter system as claimed in claim 1 receiving a voltage from a DC power source that varies over the range of 36 to 75 volts.
14. A dc/dc converter system as claimed in claim 1 receiving a voltage from a DC power source within the range of 36 to 75 volts.
15. A dc/dc converter system as claimed in claim 14 wherein the outputs of a plurality of the switching regulators are of voltage levels to drive logic circuitry.
16. A dc/dc converter system as claimed in claim 1 wherein the isolation/semi-regulation circuitry includes a capacitor at its output.
17. A dc/dc converter as claimed in claim 1 wherein a signal in the primary transformer winding circuit is used to affect the drop in output voltage.
18. A dc/dc converter as claimed in claim 17 wherein the signal in the primary transformer winding circuit indicates the current flow through the isolation stage.
19. A dc/dc converter system as claimed in claim 17 further comprising temperature compensation in affecting the drop in output voltage.
20. A method of providing multiple DC outputs comprising:
applying power from a DC power source through at least one primary winding in a primary transformer winding circuit and at least one secondary winding coupled to the at least one primary winding, the at least one secondary winding being in a secondary transformer winding circuit having plural controlled rectifiers, each having a parallel uncontrolled rectifier, and sensing a voltage in the primary transformer winding circuit to provide a feedback control signal without bridging an isolation barrier of the primary and secondary windings, the feedback control signal controlling regulation by control of duty cycle of a transistor in the primary transformer winding circuit to provide a semi-regulated, isolated output, the semi-regulated, isolated output being a voltage whose value drops due to impedance of an output path; and
from the semi-regulated, isolated output, providing plural further regulated outputs through a plurality of non-isolating switching regulators.
21. A dc-dc converter system comprising:
isolation/semi-regulation circuitry comprising:
a primary transformer winding circuit having at least one primary winding;
a secondary transformer winding circuit having at least one secondary winding coupled to at least one primary winding and having plural controlled rectifiers, each having a parallel uncontrolled rectifier; and
a control circuit that controls semi-regulation by control of duty cycle of a transistor in the primary transformer winding circuit; and
an output of the isolation/semi-regulation circuitry whose voltage value drops due to impedance of an output path; and
a plurality of non-isolating switching regulators, each receiving the output of the isolation/semi-regulation circuitry whose voltage value drops.
22. A dc/dc converter system as claimed in claim 21 wherein a switch in each of a plurality of the switching regulators is a controlled rectifier.
23. A dc/dc power converter system as claimed in claim 21 wherein signals controlling the controlled rectifiers are provided by the at least one secondary winding.
24. A dc/dc converter system as claimed in claim 21 wherein the output of the regulation/isolation circuitry is about 12 volts.
25. A dc/dc converter system as claimed in claim 21 wherein the outputs of a plurality of the switching regulators are of voltage levels to drive logic circuitry.
26. A dc/dc converter system as claimed in claim 21 receiving a voltage from a DC power source within the range of 36 to 75 volts.
27. A dc/dc converter system as claimed in claim 26 wherein the outputs of a plurality of the switching regulators are of voltage levels to drive logic circuitry.
28. A method of providing multiple DC outputs comprising:
applying power from a DC power source through at least one primary winding in a primary transformer winding circuit and at least one secondary winding coupled to the at least one primary winding, the at least one secondary winding being in a secondary transformer winding circuit having plural controlled rectifiers, each having a parallel uncontrolled rectifier, and controlling regulation by control of duty cycle of a transistor in the primary transformer winding circuit to provide a semi-regulated, isolated output, the semi-regulated, isolated output being a voltage whose value drops due to impedance of an output path; and
from the semi-regulated, isolated output, providing plural further regulated outputs through a plurality of non-isolating switching regulators.