Diodes surface contact type surface contact type or the area known as the PN junction diode is made of alloy method or diffusion method, the Zhejiang glass diodes, due to large this diode PN junction area, can withstand high current, but interpole capacitance is also large. Such devices are suitable for rectification, but not for high-frequency circuits. Key type key type diode is molten gold or silver threads on a single chip or silicon germanium formed. Its characteristics between point-contact diodes and diode alloys. Compared with point-contact, although key PN junction diode capacity slightly increased, but the positive feature is particularly good. More for switching, Shandong glass diodes, sometimes applied to detection and power rectifier (less than 50mA). In the key-type diodes, welding diodes sometimes called gold gold key type, welding silver diode is sometimes called silver key type. Monochromatic light emitting diode detector multimeter externally attached a saving 1.5V batteries, set the multimeter R × 10 or R × 100 block. This connection is equivalent to giving a multimeter in series on the voltage of 1.5V, glass diodes, the detection voltage is increased to 3V (light-emitting diode turn-on voltage of 2V). Detection, with a multimeter pen rotation touching two light-emitting diodes two pins. If the tube performance is good, there must be a normal light, this time, the black pen connects to the positive red lead connection is negative. A. detect infrared light emitting diode infrared light-emitting diode discriminating positive and negative electrodes. Infrared light-emitting diode has two pins, usually longer pin is positive, the short pin is negative. Because infrared light-emitting diodes are transparent, so that the envelope of the electrode is clearly visible, the larger a wider internal electrode to the negative electrode, and a narrow and small as the positive electrode. B. Measure the red light-emitting diode, the reverse resistance, usually forward resistance should be about 30k, 500k reverse resistance to the above, such a tube before normal use. Diodes as a p-type semiconductor and n-type semiconductor pn junction formed at the interface of the two sides to form a space charge layer, Jiangsu glass diodes, and has self-built electric field. When no voltage is applied, since both sides of the pn junction carrier concentration caused by poor diffusion current drift current and self-built electric field caused by the equal and in electrical equilibrium. When the outside has a positive voltage bias, external electric field and the field of mutual self dissipation effect of suppressing the diffusion of carriers so that the current increase caused a forward current. When the outside there is a reverse voltage bias, external electric field and further strengthen self-built electric field is formed within a certain reverse voltage range and a reverse bias voltage value independent of the reverse saturation current I0. When the applied reverse voltage is high to a certain extent, pn junction space charge of the electric field strength reaches a critical value generating carrier multiplication process, resulting in a large number of electron-hole pairs, resulting in a large reverse breakdown current value called diode breakdown. pn junction reverse breakdown Zener breakdown and avalanche breakdown of the points. Glass diodes, gold honesty, Zhejiang glass diodes provided by Qingdao integrity Technology Co., Ltd. Glass diodes, gold honesty, Zhejiang glass diodes is Qingdao integrity Technology Co., Ltd. (www.qdjcx.com) this year introduced a new upgrade, the above picture is for reference only, please call the telephone or pictures on this page, For the latest information, contact: Mr. Yang.