Hi All,
I was wondering if anyone could spell out my options, if any, in my latest venture. What I'm hoping to do is create a large (~2kw) switcher to drive a large number of high powered LEDs. Now I'm sure there will be plenty of people rushing to tell me this is a bad idea but for cost/size/complexity reasons I'm going for non-isolated. The basic scheme is going to be:
Mains > EMI Filter > Bridge Rectifier > Boost PFC (400V, 100kHz) > Buck (~300v) > 30x n type buck (~160v)
This final stage is 30 low current, asynchronously firing, current controlled n-type bucks. The question here is to do with ground referencing. There is a considerable amount of logic and n type mosfets,etc and need +12, +5, +3.3 levels. The hope was to use a PC PSU as an auxiliary supply to provide these levels and spare a lot of work(there's enough already).
As I understand, the voltages mentioned above (400, 300v) are referenced to the -ve node of the bridge rectifier. This isn't ground earth referenced. Other than the assured death that awaits me, is there any reason why a PC PSU cant have the ground earth connection removed and have its outputs reference to the -ve node of the bridge. I appreciate this would all need some incredible insulation strategy and a lot of caution but generally speaking am I missing anything? Thanks
I was wondering if anyone could spell out my options, if any, in my latest venture. What I'm hoping to do is create a large (~2kw) switcher to drive a large number of high powered LEDs. Now I'm sure there will be plenty of people rushing to tell me this is a bad idea but for cost/size/complexity reasons I'm going for non-isolated. The basic scheme is going to be:
Mains > EMI Filter > Bridge Rectifier > Boost PFC (400V, 100kHz) > Buck (~300v) > 30x n type buck (~160v)
This final stage is 30 low current, asynchronously firing, current controlled n-type bucks. The question here is to do with ground referencing. There is a considerable amount of logic and n type mosfets,etc and need +12, +5, +3.3 levels. The hope was to use a PC PSU as an auxiliary supply to provide these levels and spare a lot of work(there's enough already).
As I understand, the voltages mentioned above (400, 300v) are referenced to the -ve node of the bridge rectifier. This isn't ground earth referenced. Other than the assured death that awaits me, is there any reason why a PC PSU cant have the ground earth connection removed and have its outputs reference to the -ve node of the bridge. I appreciate this would all need some incredible insulation strategy and a lot of caution but generally speaking am I missing anything? Thanks