LM358: Current limit by LM358 in buck-boost circuit

VT,

There is something wrong in the current limit circuit , but the attachment did not work.

There are two ways to insert a file or image, I prefer the [green square icon] on the left.

VT,

I can see the circuit now. U4 looks a bit odd , becuase I think pin 8 is upper left usually pin 1 is upper left.

Do I have the pinout labeled (in red) correctly.

It seems that the 12V power is not connected to pin 8 of the op amp.

Could you measure all of the LM358 pins voltages? 

Hi

Its just horizontally flipped in schematic.

I have sent you friend request, if you can accpet can share the complete schematic also.

Thanks

VT

VT,

I looked at your circuiry. The LED should turn on anytime there is any significant output current flow. The other channel amplifies the shunt voltage by 16. If this amplified voltage can bias a diode terminated to a regulated 1.25V then output voltage will be reduced and this will reduce the output current. I see no reason that this circuit would get hot. I do not know the stability of this current limiting loop. So once it works at all, that will need to be checked.

Look for mis-wiring, solder bridges, and any un-soldered pin.  Because this got very hot, change the LM358 to a fresh unit as the first one may be damaged by now.

If you still can't get it to work make a table of op amp pin voltages and shunt voltage so I can debug using those values.