Switched mode power supply and method of production
A switched mode power supply allowing a half bridge converter to be use alone or in combination with another converter to form a full bridge converter. A common controller may be used for either half bridge or full bridge configurations. The modular approach simplifies design for a range of power supplies and reduces costs.
1. A switched mode power supply including:
interconnected first and second half bridge units; and
a control circuit configured to operate the interconnected first and second half bridge units as a full bridge converter,
wherein the first and second half bridge units are separable units configured to be interconnected to one another and wherein the first and second half bridge units and the control circuit are configurable to a first configuration wherein the control circuit operates at least one of the first and second half bridge units as a half bridge converter and a second configuration where the control circuit operates the first and second half-bridge units together as a full bridge converter.
2. A switched mode power supply as claimed in claim 1 wherein the outputs of the first and second half bridge units are connected to series connected primary windings of respective output transformers.
3. A switched mode power supply as claimed in claim 1 wherein the first and second half bridge units are provided on separate circuit boards.
4. A switched mode power supply as claimed in claim 1 wherein the control circuit is provided on a separate circuit board.
5. A switched mode power supply as claimed in claim 3 wherein the control circuit is provided on a separate circuit board.
6. A switched mode power supply as claimed in claim 1 wherein respective ones of the first and second half bridge units comprise respective first and second boost stages.
7. A switched mode power supply as claimed in claim 3 wherein respective ones of the first and second half bridge units comprise respective first and second boost stages.
8. A switched mode power supply as claimed in claim 4 wherein respective ones of the first and second half bridge units comprise respective first and second boost stages.
9. A switched mode power supply as claimed in claim 5 wherein respective ones of the first and second half bridge units comprise respective first and second boost stages.
10. A switched mode power supply as claimed in claim 1 wherein the control circuit monitors the output voltage and current of the power supply and controls switching of the first and second half bridge units to achieve a desired output voltage and current.
11. A switched mode power supply as claimed in claim 3 wherein the control circuit monitors the output voltage and current of the power supply and controls switching of the first and second half bridge units to achieve a desired output voltage and current.
12. A switched mode power supply as claimed in claim 4 wherein the control circuit monitors the output voltage and current of the power supply and controls switching of the first and second half bridge units to achieve a desired output voltage and current.
13. A switched mode power supply as claimed in claim 1 wherein a top switch of the first half bridge unit and a bottom switch of the second half bridge unit are driven by a first drive signal from the control circuit and a bottom switch of the first half bridge unit and a top switch of the second half bridge unit are driven by a second drive signal from the control circuit, wherein the second drive signal is the logical inverse of the first drive signal.
14. A switched mode power supply as claimed in claim 3 wherein a top switch of the first half bridge unit and a bottom switch of the second half bridge unit are driven by a first drive signal from the control circuit and a bottom switch of the first half bridge unit and a top switch of the second half bridge unit are driven by a second drive signal from the control circuit, wherein the second drive signal is the logical inverse of the first drive signal.
15. A switched mode power supply as claimed in claim 4 wherein a top switch of the first half bridge unit and a bottom switch of the second half bridge unit are driven by a first drive signal from the control circuit and a bottom switch of the first half bridge unit and a top switch of the second half bridge unit are driven by a second drive signal from the control circuit, wherein the second drive signal is the logical inverse of the first drive signal.
16. A method of producing a switched mode power supply comprising:
providing first and second separable half bridge units that are configured to be electrically interconnected;
providing a control circuit configurable to individually operate at least one of the first and second half bridge units as a half bridge converter in a first configuration and to operate the first and second half bridge units together as a full bridge converter;
connecting the first and second half bridge units so as to form a full bridge converter; and
connecting the control circuit to the connected first and second half bridge units in such a manner that it operates the connected first and second half bridge units as a full bridge converter.
17. A method as claimed in claim 16 including the step of connecting outputs of the connected first and second half bridge units to series connected primary windings of respective first and second output transformers.
18. A method as claimed in claim 16 including the step of connecting a top switch of the first half bridge unit and a bottom switch of the second half bridge unit to a first drive signal output of the control circuit and a bottom switch of the first half bridge unit and a top switch of the second half bridge unit to a second drive signal output of the control circuit, wherein the second drive signal is the logical inverse of the first drive signal.
19. A method as claimed in claim 17 including the step of connecting a top switch of the first half bridge unit and a bottom switch of the second half bridge unit to a first drive signal output of the control circuit and a bottom switch of the first half bridge unit and a top switch of the second half bridge unit to a second drive signal output of the control circuit, wherein the second drive signal is the logical inverse of the first drive signal.
20. A switched mode power supply as claimed in claim 1 , further comprising:
first and second transformers having primary windings connected in series and coupled to outputs of the first and second half bridge units; and
respective first and second rectifiers coupled to respective secondary windings of respective ones of the first and second transformers.
21. A method as claimed in claim 17 , further comprising connecting respective first and second rectifiers to respective secondary windings of respective ones of the first and second output transformers.