Power Fuse

[Farah]

I am repairing a 220VAC to 110VAC converter that is used for a 100watt UV lamp. because of spark, the input fuse completely damaged. which fuse appropriate for this circuit? the damaged fuse and the circuit board are attached. 

[coromonadalix]

if you know the output voltage and current of this psu,  or the total current  ...

you can summarize a value like this :    from ohms law

ex:  24vdc at 2 amps is 48 watts

48 watts  / 120vac  would give 400 ma fuse,   you could play safe with an 500ma 


sadly the fuse is the last thing to blow in a smps ...

do you have writtings on the psu casing    100w  is ok  but do you have voltage somewhere ?  if you wrote 220 to 120 vac     

it is : 100 / 120vac = 833 ma  ??   an 1 amp would be okay ?  i think  unless you have other problems

[Farah]

Thanks for your Reply.
The output of this PSU is only used to turn on a 100 watt/110VAC UV lamp (Mercury). The power supply of the lamp fan is from another board. There is no information on the body of the device, board, etc.