PC power supply problem

[alex123alex]

hi,
can you tell me what demages in power supply if we change 220V to 110V, and than plug in 220V circuit?
can you show it on the image?
thanks,

 

[BradtheRad]

Some appliances have a switch to choose between 110 or 220. Are you wondering if the supply will be destroyed if it is set to 110V, but connected to 220V? I'm pretty sure that will destroy it due to overmuch current. The only way it could survive is if the manufacturer built in safeguards.

 

[pjmelect]

If you set the voltage switch to 110v on a PC power supply and run it at 220V, you will cause the MOV's to go short circuit and blow the fuse. This is an easy fix as normally no other components are damaged. Very cheap PC power supplies may not have over voltage protection components, and in this case very extensive damage may result.
However most PC power supplies have these components.

 

[alex123alex]

 

[BradtheRad]

It has become common for power supply manufacturers to design a unit so it can adapt automatically to a large range of incoming voltage.

The label should tell you what voltages are safe for plugging it into. Can you post a photograph of the label? Also any switches which are accessible for the user to operate?

 

[c_mitra]

Where is the 220V/110V switch located in the photos? Some designs use a bridge rectifier for the 110V and use a half wave rectifier for the 220V (before the input DC filter caps). Please see if this is the case for your power supply.

 

[alex123alex]

 

[richk]

hi,
can you tell me what demages in power supply if we change 220V to 110V, and than plug in 220V circuit?
can you show it on the image?
thanks,

HI Check the in line current limiting element and the transzorbs they look like diodes and the switching transistor of mosfet

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Check the Transzorb protection device they look like diodes and the in line fuse this should not be a big fix
Also check the dc bus caps for bulging hope you get it sorted
Rich

It should be about 220 to 330 uF 350/400Wv by the mains input bridge rectifier

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The Bottom right is the in line current limiting resistor (MOV) metal oxide varistor, check if it is open circuit