Power supply device
There is provided a power supply device 100 for switching power to an output line 150 between a first power supply 120 and a parallel second power supply 122 . The power supply device 100 comprises: a first converter 130 connected to the first power supply 120 and configured to output a first voltage in a first predetermined range; and a second converter 132 connected to the second power supply 122 and configured to output a second voltage in a second predetermined range. The outputs of the first and second converters 130, 132 are connected together on the output line 150 , and the first and second converters 130, 132 are arranged to maintain a voltage on the output line 150 within a third predetermined range.
1. A power supply device for switching power to an output line ( 150 ) between a first power supply ( 120 ) and a parallel second power supply ( 122 ), the power supply device comprising:
a first power module ( 130 ) connected to the first power supply ( 120 ) and configured to output a first voltage in a first predetermined range; and
a second power module ( 132 ) connected to the second power supply ( 122 ) and configured to output a second voltage in a second predetermined range;
a control arrangement configured to control the output voltages of the first and second power modules ( 130 , 132 ) within the respective first and second predetermined ranges, and thereby control which of the first power module ( 130 ) and second power module ( 132 ) provides power to the output line ( 150 );
wherein the outputs of the first and second power modules are connected together on the output line ( 150 ); and
wherein the first and second power modules ( 130 , 132 ) are arranged to maintain a voltage on the output line ( 150 ) within a third predetermined range.
2. A power supply device as claimed in claim 1 , wherein the first power module ( 130 ) and the second power module ( 132 ) are configured so that the first predetermined range overlaps with the second predetermined range.
3. A power supply device as claimed in claim 1 , wherein the control arrangement is configured to increase and/or decrease voltage on the feedback line ( 154 ) of the first power module ( 130 ); and/or is configured to increase and/or decrease voltage on the feedback line ( 156 ) of the second power module ( 132 ).
4. A power supply device as claimed in claim 3 , wherein the control arrangement is arranged to simultaneously increase voltage on the feedback line ( 154 ) of the first power module ( 130 ) while decreasing voltage on the feedback line ( 156 ) of the second power module ( 132 ); and/or to simultaneously decrease voltage on the feedback line ( 154 ) of the first power module ( 130 ) while increasing voltage on the feedback line ( 156 ) of the second power module ( 132 ).
5. A power supply device as claimed in claim 4 , comprising a single control input for controlling the control arrangement.
6. A power supply device as claimed in claim 1 , wherein the control arrangement comprises a first control resistor (R 5 ) connected to a feedback line ( 154 ) of the first power module ( 130 ) for varying voltage on the feedback line ( 154 ) of the first power module ( 130 ) by varying current through the first control resistor (R 5 ).
7. A power supply switching device as claimed in claim 6 , wherein the control arrangement comprises a second control resistor (R 7 ) connected to the feedback line ( 156 ) of the second converter ( 132 ) for varying voltage on the feedback line ( 156 ) by varying current through the second control resistor (R 7 ).
8. A power supply device as claimed in claim 6 , wherein the first control resistor (R 5 ) has a resistance at least an order of magnitude greater than either or both of the resistors of a first voltage divider (R 1 , R 2 ), the first voltage divider being arranged to control a feedback voltage on the feedback line ( 154 ) of the first power module ( 130 ).
9. A power supply device as claimed in claim 1 , wherein the first predetermined range is 13.6V to 14.0V, and/or wherein the second predetermined range is 13.4V to 13.8V.
10. A power supply device as claimed in claim 1 , wherein the third predetermined range is 13.6V to 13.8V.
11. A power supply device as claimed in claim 1 , wherein the first power module ( 130 ) and/or second power module ( 132 ) is a linear or switch mode converter.
12. A power supply device for switching power to an output line ( 150 ) between a first power supply ( 120 ) and a parallel second power supply ( 122 ), the power supply device comprising:
a first power module ( 130 ) connected to the first power supply ( 120 ) and configured to output a first voltage in a first predetermined range;
a second power module ( 132 ) connected to the second power supply ( 122 ) and configured to output a second voltage in a second predetermined range; and
a first voltage divider (R 1 , R 2 ) arranged to control a feedback voltage on a feedback line ( 154 ) of the first power module ( 130 ), and a second voltage divider (R 3 , R 4 ) arranged to control a feedback voltage on a feedback line ( 156 ) of the second power module ( 132 ), wherein the first voltage divider (R 1 , R 2 ) and the second voltage divider (R 3 , R 4 ) are connected to the output line ( 150 );
wherein the outputs of the first and second power modules are connected together on the output line ( 150 ); and
wherein the first and second power modules ( 130 , 132 ) are arranged to maintain a voltage on the output line ( 150 ) within a third predetermined range.
13. A power supply device for switching power to an output line ( 150 ) between a first power supply ( 120 ) and a parallel second power supply ( 122 ), the power supply device comprising:
a first power module ( 130 ) connected to the first power supply ( 120 ) and configured to output a first voltage in a first predetermined range;
a second power module ( 132 ) connected to the second power supply ( 122 ) and configured to output a second voltage in a second predetermined range;
a controller configured to periodically switch between the first power supply ( 120 ) and second power supply ( 122 );
wherein the outputs of the first and second power modules are connected together on the output line ( 150 ); and
wherein the first and second power modules ( 130 , 132 ) are arranged to maintain a voltage on the output line ( 150 ) within a third predetermined range.
14. A method of switching an output line ( 150 ) between a first power supply ( 120 ) and a second power supply ( 122 ), comprising:
providing a first power module ( 130 ) and a second power module ( 132 ), wherein the outputs of the first and second power modules ( 130 , 132 ) are connected together on the output line ( 150 ); and
decreasing an output voltage of the first power module ( 130 ) and simultaneously increasing an output voltage of the second power module ( 132 ) to switch between the power supplies ( 120 , 122 ) and maintain the voltage on the output line ( 150 ) within a predetermined range.