1N4148 is a small high-speed switching diode, which switches quickly. It is widely used for unidirectional isolation of circuits with higher signal frequencies, such as communications, computer boards, television circuits, and industrial control circuits.

1n4148 is silicon tube or germanium tube

It can be tested with an ordinary multimeter. General silicon tube forward resistance

1. It should be 1N. This is the naming method for semiconductor devices adopted in many foreign countries. 1 represents a PN junction in the device, and N represents a material, which is an N-type silicon semiconductor. Is the product generation.

2. As mentioned above, it is a silicon tube.

3. The working principle of the diode is to use the external electric field to offset the PN junction to form an electric potential barrier to allow current to pass. The voltage drop is mainly caused by the offset of the electric potential barrier. (If the polarity is reversed, the electric potential barrier will be increased, and the current will not pass, which is called "cut off")

The difference between silicon tube and germanium tube

The diode has the characteristic of unidirectional conduction. The main functions are rectification, voltage stabilization, and detection. In addition, there are light-emitting diodes added with different materials for indication and illumination.

The most important characteristic of a diode is unidirectional conductivity. In the circuit, current can only flow in from the anode of the diode and flow out of the cathode. The following is a simple experiment to illustrate the forward and reverse characteristics of the diode.

The circuit properties of silicon diode and germanium diode are the same, and the manufacturing process is also the same. Due to the difference in materials, the thermal stability of silicon diodes is good, and the thermal stability of germanium diodes is slightly worse. Their differences are mainly manifested in the following aspects.

(1) The forward voltage drop of the germanium diode is small, and the forward voltage drop of the silicon diode is large; the dead zone voltage of the germanium diode is small (O.2V), and the dead zone voltage of the silicon diode is large (0.5V).

(2) The reverse current of germanium diode is large; the reverse current of silicon diode is small, and the performance is stable

(3) Temperature changes have a greater impact on germanium diodes, but less on silicon diodes. Therefore, silicon tubes have better high temperature resistance than germanium tubes.

(4) The reverse breakdown voltage of germanium diodes is low, and the reverse breakdown voltage of silicon diodes is high.