Judging the quality of the field effect camp

The quality of field-effect transistors can be easily judged using a multimeter The method is to use a multimeter to measure the resistance value between the electrodes of the field-effect transistor, and then compare it with the resistance value indicated in the manual.

The specific measurement method is to place the multimeter in the Rx10 or R x 100 range, and first measure the resistance between the source S and drain D, which is generally in the range of tens of ohms to several thousand ohms (different types of field-effect transistors have different resistance values).

If the measured resistance value is infinite, it may be an internal pole break; If the measured resistance value is very small, it may be due to pipe breakdown and damage; If the measured resistance value is greater than the specified value, it may be due to poor internal contact of the diode.

Then place the multimeter in the R x 10k gear Measure the resistance values between the gate and source, gate and drain, and the gates G1 and G2 of the double gate transistor. When all the measured resistances are infinite, it indicates that the transistor is good; If the measured resistance is too small or is a circuit, it indicates that the diode is faulty.