darlington replacement ?

Sep 08, 2007 4 Replies

hi, i have a blown npn darlington 2sd1525 from a cars fan speed controller , and its rated at 30 amp , doesnt this seem excessive ? i doubt it if the fan would draw more than 5 amp ....



anyways , i have had a pretty good look on the net , and the only direct replacements are only available over seas , is there a commonly available equivalent npn darlington ? that i could use ?



thanks, mark k


No, it doesn't 'seem excessive'. The _instantaneous_ peak current as you turn on, will typically be several times the 'normal' operating current. Transistors, blow very quickly, and if the unit is fused at perhaps 7A, you would need to be using a transistor this sort of size, to have much hope of the fuse blowing before the transistor... Since the unit is a 'speed controller', it is almost certainly a PWM design,

Just get a 2SD1525. Several US suppliers show them in stock, who will post to Australia. 'aeri' in Australia, will supply directly, if you don't want to fiddle around dealing with an overseas company.

Best Wishes

hi, would either of these be ok ?

MJ11016 NPN Power Darlington Transistor MJ11032 NPN Power Darlington Transistor

these are easier to get for me.

thanks, mark k

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