Hello everyone,
As a hardware designer in power electronics, sometimes I must deal with multiples supply to create 3.3V and 5V for electronics but also isolated +15V/0V or +15V/-9V to drive MOSFETs in HV or LV... Basically this supply can be LDO or isolated chip (like in SIP or DIP package). All of these can take à 5V input and generate the proper supply value in output.
I can be interested in creating a global 5V supply (from the main 230V line) and them put as power supply as I need in cascade with this main 5V supply. It can be cost effective to have one main supply with lots of functionality (or safety/iso requirement) and then several cheaper supply instead of tens of expensive supply which all takes the 230V as input.
I attached an example of what I mean.
I can calculate the power for each DCDC with the load I have.
My concern is about the choice of the total power of the MainACDC converter.
Most of time the consumption of electronics is very low but the standard for isolated DCDC supply is 1W minimum (some 0.5W or less existes but it quite rare and without lost of brand or package). So let say my 3 DCDC supply are 1W rated but the consumption of each never exceed 0.3W in worst case
Can I choose a MainACDC of 1W rated (1W > 3x0.3W) or I have to select a 3W MainACDC because of 3x1W rated DCDC supply ?
I believe the answer is not trivial because of load regulation/stability... If the main supply is not able to give enough charge maybe the total system never start up ?
I would be very interrested by your point of view on this and the rules of thumb if it exists.
Regards,
M. BLANC
As a hardware designer in power electronics, sometimes I must deal with multiples supply to create 3.3V and 5V for electronics but also isolated +15V/0V or +15V/-9V to drive MOSFETs in HV or LV... Basically this supply can be LDO or isolated chip (like in SIP or DIP package). All of these can take à 5V input and generate the proper supply value in output.
I can be interested in creating a global 5V supply (from the main 230V line) and them put as power supply as I need in cascade with this main 5V supply. It can be cost effective to have one main supply with lots of functionality (or safety/iso requirement) and then several cheaper supply instead of tens of expensive supply which all takes the 230V as input.
I attached an example of what I mean.
I can calculate the power for each DCDC with the load I have.
My concern is about the choice of the total power of the MainACDC converter.
Most of time the consumption of electronics is very low but the standard for isolated DCDC supply is 1W minimum (some 0.5W or less existes but it quite rare and without lost of brand or package). So let say my 3 DCDC supply are 1W rated but the consumption of each never exceed 0.3W in worst case
Can I choose a MainACDC of 1W rated (1W > 3x0.3W) or I have to select a 3W MainACDC because of 3x1W rated DCDC supply ?
I believe the answer is not trivial because of load regulation/stability... If the main supply is not able to give enough charge maybe the total system never start up ?
I would be very interrested by your point of view on this and the rules of thumb if it exists.
Regards,
M. BLANC
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