pniewy wrote: What does it mean to charge the gate? How to do it?
The gate is galvanically separated from the channel and forms a kind of capacitor with it.
If you apply any voltage between the gate and the source, this capacitor will charge. If the voltage between the gate and the source is greater than the threshold voltage for a given type of MOSFET, the transistor will start to conduct.
Note: the gate-source voltage should always be less than +/- 20V. Otherwise, the gate-channel breakdown will occur and the transistor will be irretrievably damaged. Static electricity can do this too Checking the MOSFET transistor (with enriched channel - non-conductive when Ugs = 0V).
1. We close the gate with the source: then there should be a gap between the source and drain (channel cut off)
For the N-type channel, plus we put it on the drain.
With the opposite polarity, the diode should open, connected in parallel to the transistor channel (drain-cathode, source-anode) - voltage drop approx. 0.8V
For P channel, minus drain, plus source and gate.
2. Checking if the transistor turns on:
After applying a voltage higher than the threshold (usually> 3V) between the gate and the source, the transistor should open - the resistance measurement of the source channel should show low resistance.
