Hello I'm fixing a 19" monitor switchmode supply which has a shorted schottky diode, type SB5150. That's a hard part to find where I live, so I'm wondering about replacements.
SB5150 is a Schottkey Barrier diode rated 5Amp and 150V reverse voltage. But why so high spec? The LCD monitor supplies 12V (for backlights - maybe 1amp) + 5V (for video/audio) and it looks like a standard supply layout with this diode is on the low voltage side. So why 150V 5 Amps? I'm wondering if I could get away with a smaller device like 3A 100V (or less)...?
But on the other hand if it was over-rated then why did the original die?
Also, after quite some googling I'm still not clear on a Schottky Barrier vs 'normal' Schottky diode other than junction capacitance... but I don't understand the implications of this. I have urges to stick in any old diodes I find in some dead computer PSUs and hope it works....?????
Can someone familiar with switchmodes comment on likely substitutes?
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schottky specification in LCD monitor switchmode supply
in Power Electronics
Posted
Hello
I'm fixing a 19" monitor switchmode supply which has a shorted schottky diode, type SB5150. That's a hard part to find where I live, so I'm wondering about replacements.
SB5150 is a Schottkey Barrier diode rated 5Amp and 150V reverse voltage. But why so high spec? The LCD monitor supplies 12V (for backlights - maybe 1amp) + 5V (for video/audio) and it looks like a standard supply layout with this diode is on the low voltage side. So why 150V 5 Amps? I'm wondering if I could get away with a smaller device like 3A 100V (or less)...?
But on the other hand if it was over-rated then why did the original die?
Also, after quite some googling I'm still not clear on a Schottky Barrier vs 'normal' Schottky diode other than junction capacitance... but I don't understand the implications of this. I have urges to stick in any old diodes I find in some dead computer PSUs and hope it works....?????
Can someone familiar with switchmodes comment on likely substitutes?
thank you
Mike