MOSFET(metal oxide field effect transistor) please can you tell me why all of mine are short-circuit?They are new!
i have bought 2 mosfets (irf z44v and irf 540) and the drain is live even when the gate is not connected to anything or 0v?
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answers
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Answer it!
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MOSFET's works differently from transistors. A transistor needs current flowing into (or out) of the base to 'turn on'. A MOSFET needs a small voltage charge at the gate to 'turn on', the gate holds the charge like if it is a capacitor. That is why they stay on when the gate is not connected to anything. I suggest putting a 10k resistor between the gate and the source of the MOSFET to drain the charge from the gate.
Jun 24, 2009. 9:51 AM12V (author)
says:
i have just tried this but made no difference.. have you ever had problems with one of two(meaning i may have a bad one)? when i first tried it i connected the gate to the source voltage has this burned it out also how static sensitive are they? also is it energized when the gate is - or+?
How are you testing them? The IRF540 has a diode (cathode to drain, anode to source) across it. If you're using a multimeter low resistance check it may well be seeing this. (If you reverse the connections it should be high res with the gate at 0V.)
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