Patch component is the product of miniaturization and high integration of electronic equipment, and is a new type of micro-miniature component without lead or short lead. Because the size of the patch component is very small, the model similar to the conventional component can not be written on the surface of the component package, and there are inevitable problems for detection. This article mainly on the resistance, capacitance, inductance, diode (transistor) and so on these chip components detection as an example, a simple introduction to the digital multimeter detection of chip components good or bad skills. However, this test is based on the understanding of the structural principle of the components to test, in order to make a correct decision.
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The following is a brief introduction to the skills of testing some electronic components with a multimeter. (1) The resistance test patch resistor is generally printed with resistance value identification characters, such as 103 (resistance value of 10K), 102 (resistance value of 1K), with a multimeter resistance file test and then compare the value of the target to know whether it is normal.
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(2) Capacitance test Many digital multimeters have capacitance test gear, the capacitor is first short-circuit discharge, adjust to the capacitance test gear, and then connect the capacitor to the two test ports dedicated to the capacitor, and then you can read the capacity, if only roughly determine the capacitor is good or bad, use the resistance gear or buzzer test. The capacitor should not measure the resistance value (infinity) or the resistance from small to large and then to infinity, then it is normal.
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(3) Diode test according to the unidirectional conductivity of the diode, with the buzzer, the red and black pen first randomly connected, if the conduction (with a numerical display), the red pen is connected to the positive electrode of the diode, the black pen is connected to the negative electrode, the red-black ratio is switched, there should be no display value (and the default untested state of the display content), so that the test twice can be judged as normal. Otherwise, it is abnormal.
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(4) inductance test some multimeter has an inductance test file, can test the inductance, the method and the test capacitance are close, no longer detailed, if there is no inductance test function, can only use buzzer or resistance file test inductance is open (normal inductance buzzer test multimeter will make a sound), if the inductance short circuit, it can not be determined. There is a special capacitance and inductance meter can be tested, LCR bridge is best used.
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(5) Triode test according to the unidirectional conductivity of the transistor, with a buzzer file, red and black pen first randomly connected, if the conduction (with a numerical display), the red pen is connected to the positive electrode of the two triode, the black pen is connected to the negative electrode, the red-black ratio is switched, there should be no display value (and the default untested state of the display content), so that the test twice can be judged as normal. Otherwise, it is abnormal.
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(6) The ohm file of the multimeter for magnetic bead testing, measuring both ends of the pin of the magnetic bead, pass (resistance value less than 1 ohms) is intact.