cupoftea
Advanced Member level 5
Hi,
The below shows inrush current components, but as yet, why do we still not have proper inrush management ICs for <75W , 90-265VAC
offline SMPS's? One still has to do it with expensive discrete components and an (expensive to get programmed) micro.
Supposing , for 240VAC input, your inrush relay shorts out the inrush resistor after a suitable delay (it has to be delayed because the
"PSU enabled" voltage has to be low enough for 90vac). All is very well, but then supposing the mains suffers a dip down to 100VAC for 5 minutes....
and then suddenly returns to its correct value of 240VAC..then the inrush relay will still be shorting out the inrush resistor when the mains
recovers back up to 240VAC.....and so you then suffer massive unlimited inrush....and you either seriously weaken,
or nuisance trip, your mains input fuses...and your entire equipment
no longer works. -And yet still, we have no ICs to manage this. Do you know why?
The below shows inrush current components, but as yet, why do we still not have proper inrush management ICs for <75W , 90-265VAC
offline SMPS's? One still has to do it with expensive discrete components and an (expensive to get programmed) micro.
Supposing , for 240VAC input, your inrush relay shorts out the inrush resistor after a suitable delay (it has to be delayed because the
"PSU enabled" voltage has to be low enough for 90vac). All is very well, but then supposing the mains suffers a dip down to 100VAC for 5 minutes....
and then suddenly returns to its correct value of 240VAC..then the inrush relay will still be shorting out the inrush resistor when the mains
recovers back up to 240VAC.....and so you then suffer massive unlimited inrush....and you either seriously weaken,
or nuisance trip, your mains input fuses...and your entire equipment
no longer works. -And yet still, we have no ICs to manage this. Do you know why?