Buck converter - 72V to 24V

Thread Starter

gilley

Joined Nov 23, 2014
23
A load will be AC motor, but I don't know which one for sure. But I do have schematic of H bridge with elements ( without motor ) if it will be of any help.
 

Thread Starter

gilley

Joined Nov 23, 2014
23
Can u explain maybe how to calculate that , or provide some resources ? :):)

edit:

This buck converter that I am designing is going to give 12 V to power the IC on H bridge (ir2112) and few optocuplers , he will not give and voltage to ac motor, so is AC motor still needed to calculate it ?
 
Last edited:

Jony130

Joined Feb 17, 2009
5,487
H-bride without load do not draw current. As for the optocoupler it's depend on the resistors value you use in the circuit.
So maybe show as a schematic, so that we can be more precise in our assumptions.
 

Thread Starter

gilley

Joined Nov 23, 2014
23
Sorry Jony It seems I have misguided you. I explained it wrong.

The H bridge will have load ( AC motor ) and it will be powered with 72 V ( or maybe bit higher, but let's assume it's 72V ) , and I am designing buck converter that will convert some of that 72V and give me power to turn on H bridge ( as in IC ir2112 and these mosfets and optocuplers), it will not have any connection to AC motor nor it will need to power it.

This is schematic of 1/2 of bridge, second one is just mirrored.
 

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Jony130

Joined Feb 17, 2009
5,487
So your buck converter will only provide a power for Vdd part. If so you don't need to worry about power consumption. Because the static currents are very low as you can read in datasheet.
 

Thread Starter

gilley

Joined Nov 23, 2014
23
Yes, my buck will only provide power for Vdd part :)

May I ask you where did you find that info about static currents in datasheet. Apologies if I ask ridiculous questions but I really don't know.
 
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