quick question

[timwebb]

i have a auto tek 200x. im working on the power supply. and it has irf34's with 100 ohm gate resistor in it. i wanted to use irf44 should i lower the gate resistor or will the 100ohm be fine?

[Perry Babin]

They should be OK but as always when making changes to circuits, you must test thoroughly. In this case, you must make sure that the FETs run cool when the power supply is at the maximum duty cycle. If it's a regulated power supply, you may need to decrease the input voltage to force the duty cycle to increase.

[sofaspud]

Did you mean IRFZ34 and IRFZ44? I had some trouble finding "IRF34" but found these datasheets easily.
A preliminary look shows these are very similar, with the biggest differences in Rds and Id. Lower and higher respectively for the 44, as you might expect. The gate threshold voltages are equal.