What does HFE mean on a multimeter
The HFE file on the multimeter is used to measure the current magnification of the crystal triode, and all such meters have sockets for measuring the transistor. The hFE file is mainly used to measure the magnification β value. Before the measurement, it is necessary to determine whether the triode is PNP or NPN, and at the same time determine the polarity of each pin.
How to use: When measuring, insert the triode into the corresponding polarity jack, and then you can read the current magnification of the triode.
Extended information:
The head of the multimeter is a sensitive galvanometer. The dial on the head is printed with various symbols, scale marks and values. The symbol A-V-Ω indicates that the ammeter is a multimeter that can measure current, voltage and resistance.
There are multiple scale lines printed on the dial, among which the one marked with "Ω" on the right is the resistance scale line, the right end is zero, the left end is ∞, and the scale value distribution is uneven. The symbol "-" or "DC" means direct current, "~" or "AC" means alternating current, and "~" means the scale line shared by AC and DC. Several rows of numbers under the scale line are the scale values corresponding to the different positions of the selector switch.
How the multimeter works:
The basic principle of the multimeter is to use a sensitive magnetoelectric DC ammeter (microampere meter) as the meter head. When a small current passes through the meter head, there will be a current indication. However, the meter head cannot pass a large current, so some resistors must be connected in parallel or in series on the meter head to shunt or lower the voltage, so as to measure the current, voltage and resistance in the circuit.
What do hfe, PNP, NPN on the multimeter mean?
HFE is the abbreviation of the direct current amplification factor of the triode, which is the current magnification of the triode; PNP and NPN represent two types of triodes.
When the triode is turned on, IE=(magnification +1)*IB has nothing to do with ICB. When ICB=0 ICB>0, there may be a problem with the triode, so when the triode is working normally, whether it is working in the amplification area or the saturation area ICB =0. When UEB>0.7V (silicon) (germanium 0.2V), RC/RB
The difference between a PNP transistor and an NPN transistor is that the directions of the two PN junctions are inconsistent.
PNP is a common cathode, that is, the N junctions of the two PN junctions are connected as the base, and the other two P junctions are used as the collector and emitter respectively; the circuit diagram is marked as a triode with an arrow facing inward. NPN is the opposite.
