Dear Engineers,
We wish to design a modular power supply of the following spec:
Vin = 42-59VDC (14S LiPO)
Vout = 12V
Iout = 11A
Isolated (500V)
Not allowed to use fans to cool it….just heatsink.
Enclosure is a totally sealed carbon fibre box of dimension 50cm x 20cm x 10cm (high).
Max ambient outside of box = 45degC.
Given the non-use of fans, I believe you would agree with me that this more or less confines us to a Vicor module type solution? Due to the greater thermal conductivity of the material of the vicor modules.
For example, A Vicor PRM48AT480T400A00 cascaded with a Vicor VTM48ET120T025A00 would cover our spec. Their datasheets give the thermal resistance of their hottest component to the case as 1 degC/W. You simply can't get that low with "open PCB" type DCDC modules, because they use gap-pad to thermally couple to their little metal base-plate.
“Open PCB” type DCDC modules such as eg the Murata UEE-12/12.5-D48NB-C just can’t compete for such a fan-less application. Do you agree?
The power components of the UEE-12/12.5-D48NB-C are gap-padded to the metal base-plate. Clearly, gap pad isn’t as good a thermal conductor as the Vicor module material. The UEE-12/12.5-D48NB-C module’s datasheet doesn’t even provide any thermal resistance figures.
Clearly , the “open PCB” type DCDC modules must have a fan blowing over them in order for them to operate at anywhere near maximum power. Do you agree?
Vicor PRM48AT480T400A00 datasheet
Vicor VTM48ET120T025A00 datasheet
Murata UEE-12/12.5-D48NB-C datasheet
http://www.murata.com/products/productdata/8807039893534/uee150w.pdf?1583754815000
Here is a picture of an “open-PCB” type , “non-Vicor” DCDC module…..
http://www.digikey.co.uk/product-de...2-12-5-D48NM-C/UEE-12-12-5-D48NM-C-ND/4747528
……You can clearly see that its meant to only be used with blown air. There is no high-thermal-conductance potting like you get in the Vicor modules.
Surely you agree, that our Fan-less spec predicates a Vicor DCDC module approach?
We wish to design a modular power supply of the following spec:
Vin = 42-59VDC (14S LiPO)
Vout = 12V
Iout = 11A
Isolated (500V)
Not allowed to use fans to cool it….just heatsink.
Enclosure is a totally sealed carbon fibre box of dimension 50cm x 20cm x 10cm (high).
Max ambient outside of box = 45degC.
Given the non-use of fans, I believe you would agree with me that this more or less confines us to a Vicor module type solution? Due to the greater thermal conductivity of the material of the vicor modules.
For example, A Vicor PRM48AT480T400A00 cascaded with a Vicor VTM48ET120T025A00 would cover our spec. Their datasheets give the thermal resistance of their hottest component to the case as 1 degC/W. You simply can't get that low with "open PCB" type DCDC modules, because they use gap-pad to thermally couple to their little metal base-plate.
“Open PCB” type DCDC modules such as eg the Murata UEE-12/12.5-D48NB-C just can’t compete for such a fan-less application. Do you agree?
The power components of the UEE-12/12.5-D48NB-C are gap-padded to the metal base-plate. Clearly, gap pad isn’t as good a thermal conductor as the Vicor module material. The UEE-12/12.5-D48NB-C module’s datasheet doesn’t even provide any thermal resistance figures.
Clearly , the “open PCB” type DCDC modules must have a fan blowing over them in order for them to operate at anywhere near maximum power. Do you agree?
Vicor PRM48AT480T400A00 datasheet
Vicor VTM48ET120T025A00 datasheet
Murata UEE-12/12.5-D48NB-C datasheet
http://www.murata.com/products/productdata/8807039893534/uee150w.pdf?1583754815000
Here is a picture of an “open-PCB” type , “non-Vicor” DCDC module…..
http://www.digikey.co.uk/product-de...2-12-5-D48NM-C/UEE-12-12-5-D48NM-C-ND/4747528
……You can clearly see that its meant to only be used with blown air. There is no high-thermal-conductance potting like you get in the Vicor modules.
Surely you agree, that our Fan-less spec predicates a Vicor DCDC module approach?
Last edited: