IRFZ44N as switch

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dark_soul

New Member

• Sep 20, 2010

• #1

Greetings, I have a small problem with the mosfet IRFZ44N as switch the first pulse the mosfet turn on and never turn off, which I need consider to polarize the mosfet to work as a switch, attached diagram.

TLC555 generate a pulse with frecuency = 1 KH and 20% Duty cycle aprox.

Thank you for your help.

 

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MikeMl

Well-Known Member

Most Helpful Member

• Sep 20, 2010

• #2

What kind of battery? You are drawing almost 1A off it. Have you checked the voltage across the battery terminals after the FET turns on?

 

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dark_soul

New Member

• Sep 21, 2010

• #3

Hi, thanks for your reply, is a DC source with transformer 5V - 2A.

 

D

dark_soul

New Member

• Sep 21, 2010

• #4

Hi, thanks for your reply, the DC source is with transformer 5V - 2A

 

MikeMl

Well-Known Member

Most Helpful Member

• Sep 21, 2010

• #5

What is the 5Ω load, actually?

Have you measured the power supply's voltage sag when the load turns on?

How hot (to the touch) is the MOSFET?

At 4.5V gate drive, the MOSFET is just barely turned on, it could be getting stinking hot.