Monochromatic light emitting diode in the multimeter detects external attaching an economizer 1.5V dry domestic varactor diode, the multimeter set R × 10 or R × 100 block. This connection is equivalent to giving a multimeter in series with a voltage of 1.5V on the domestic varactor model, the detection voltage is increased to 3V (light-emitting diode turn-on voltage of 2V). Detection, with a multimeter two pen rotation of two light-emitting diode contact pins. If the tube performance is good, there must be a normal light-emitting diode varactor domestic manufacturers, at this time, the black pen connects to the positive red lead connection is negative. Infrared light-emitting diodes detect infrared light emitting diode A. discriminating positive and negative electrodes. Infrared light-emitting diode has two pins domestic varactor device, usually a long pin is positive, the short pin is negative. Infrared light-emitting diode due was transparent, so the envelope of the electrodes are clearly visible, the larger a wider internal electrode as the anode, and a narrow and small for the positive electrode. B. Measure the red light-emitting diodes, the reverse resistance, usually forward resistance should be around 30k, reverse resistance should be at least 500k, this pipe before normal use. 1, the role of the varactor diode is a semiconductor device utilizing a variable capacitance between the PN junction made of the principle, as a variable capacitor for use in high frequency tuning, communications circuits. Belonging to the varactor diode reverse biased diode, a reverse bias voltage to change on the PN junction, can change the PN junction capacitance. The higher the reverse bias junction capacitance the less, the inverse relationship between the bias voltage and junction capacitance is nonlinear, as shown at right. 2, illustrating the relationship between the varactor diode and the capacitance value of the reverse bias values: (a) a reverse bias voltage increases, resulting in reduced capacitance; (b) reducing the reverse bias voltage, resulting in increased capacitance. Error range is a predetermined capacitance varactor capacitance range. Data table will display the minimum, nominal and maximum values, which are often painted in FIG. Domestic varactor supply | Domestic varactor | gold credit provided by the Science and Technology Industrial Co., Ltd. Qingdao integrity. Integrity Technology Co., Ltd. Qingdao (www.qdjcx.com) strong, credible, in Qingdao, Shandong diode industry has accumulated a large number of loyal customers. The company better work attitude and constantly improve the integrity of innovative ideas will lead the gold into the brilliant and you work for a better future!