VSef
Newbie level 6
Hello,
I need to design a power supply that is connected to the utility (220V rms) and outputs both 22Vdc and 5Vdc. I have a 220V to 24V transformer after which I have a full bridge rectifier and a capacitor to maintain proper DC voltage of about 33Vdc. I have loads that consume 100mA from my 22Vdc supply and about 80mA from my 5Vdc supply.
I have several thoughts of how to accomplish this:
#1) Use a buck converter to reduce the 33Vdc to 22Vdc and supply the needed loads. Connected the Vin of a second buck converter (the one that outputs 5Vdc) to the output of the first buck converter.
Would the input current ripple of the 2nd buck converter affect the system? Would the output ripple generated from the 1st buck converter affect the 2nd buck's operation?
#2) Use a buck converter (#1) to reduce the 33Vdc to 22Vdc and supply the needed loads and use a second buck converter (#2) to reduce the 33Vdc to 5Vdc and supply the needed loads. The outs and ins of the buck converters are not connected in this configuration. However if buck #1 fails buck #2 would still operate, where as in configuration #1 the failure of the 1st buck prevents buck #2 from working which is better suited for my application.
How do you think this case should be handled? Do you have any other options?
Thank you
I need to design a power supply that is connected to the utility (220V rms) and outputs both 22Vdc and 5Vdc. I have a 220V to 24V transformer after which I have a full bridge rectifier and a capacitor to maintain proper DC voltage of about 33Vdc. I have loads that consume 100mA from my 22Vdc supply and about 80mA from my 5Vdc supply.
I have several thoughts of how to accomplish this:
#1) Use a buck converter to reduce the 33Vdc to 22Vdc and supply the needed loads. Connected the Vin of a second buck converter (the one that outputs 5Vdc) to the output of the first buck converter.
Would the input current ripple of the 2nd buck converter affect the system? Would the output ripple generated from the 1st buck converter affect the 2nd buck's operation?
#2) Use a buck converter (#1) to reduce the 33Vdc to 22Vdc and supply the needed loads and use a second buck converter (#2) to reduce the 33Vdc to 5Vdc and supply the needed loads. The outs and ins of the buck converters are not connected in this configuration. However if buck #1 fails buck #2 would still operate, where as in configuration #1 the failure of the 1st buck prevents buck #2 from working which is better suited for my application.
How do you think this case should be handled? Do you have any other options?
Thank you