Hi, sorry for my bad english. I wanna ask this :

So i have a DC buck step down 200W 15A.
And the details are :

-Input : 8-60V
-Output : 8-36V (adjustable, with trimpot)

Take a good look :

Spoiler

And by mistake i plugged wrong, i plugged input voltage to OUT terminal, then the capacitor explodes.


Then, i bring my step down to local repair shop, And the crew replaced blown caps to 25V-1000uf (yellow caps), different than original caps(green caps) (35V,470uf) (see by pics, the yellow caps is the replacement of blown caps)

and i got worried, the voltage isnt same, but the repairmen said its okay. Yeah i always use this for step down to 12V, but, what if i twisted the trimpot to 35v? will it blow up again? The repairmen said "nah its okay go 35V, it will go fine"

But im not so sure, so i asked here.

But the device is working properly, because i set it up to 12V.

 

Welcome to allaboutcircuits.com. Your English is fine.

You are right to be worried if you ever try to go much over 20 volts the risk of capacitor failure is great. This capacitor needs to be rated at 120% of the highest voltage you plan to use.

 

Welcome to allaboutcircuits.com. Your English is fine.

You are right to be worried if you ever try to go much over 20 volts the risk of capacitor failure is great. This capacitor needs to be rated at 120% of the highest voltage you plan to use.

oh also i remember the repairmen said "that 25V is in AC, so in DC it would be easy to this caps"

 

The capacitor in the picture was only designed to operate with DC. The technician doesn't know what he is talking about or he is lying.