I'm using the following MOSFET:
https://www.sparkfun.com/datasheets/Components/General/RFP30N06LE.pdf
I have 5V going into Gate, and source is connected to ground. My understanding from the datasheet is that, this would be enough to allow Vds.
My multimeter does detect the Vgs of 5V, but does not detect any voltage between drain and source.
Why is there no voltage between drain and source even though i've met the threshold Vgs?
The FET is an N-channel, so it’s being turned on with a positive gate-source voltage. Since your source is grounded, it would be expected that the drain would also be ground when Vgs is above the turn-on threshold.
What is connected to the drain? It would help to post a schematic at this point.
If nothing is connected to the drain, use an ohmmeter to test the drain-source resistance. It should be close to zero with the FET on, and infinite (open) with the FET off. Make sure the + side is on the drain otherwise you’ll be measuring the body diode.
If your power supply does not have enough current to drive the SERVO then adding a transistor or MOSFET will not magically give you more current for the SERVO.
If what you really meant was that the controlling MCU does not have enough drive on its output pin to control a servo then it is possible to use a transistor to buffer the MCU output. The transistor can switch more current to the SERVO than a typical MCU pin.
