How to use a multimeter to test common electronic components?
Whenever the circuit board can not run in accordance with normal conditions, after checking the line and no problem, it is likely that there are electronic components are bad, if you want to repair the problem components must be found, and then replace a, but find the problem components is a technical job, there are certain skills, today we will teach you how to go to how to use a multimeter to detect some commonly used electronic components.
Resistance Detection
Detect the resistance of the most direct method is to use the multimeter resistance file for measurement, generally in the resistance will be marked on the resistance size, select the appropriate resistance file, the red and black pens connected to the two ends, if the readings are close to the normal, or else bad, in the measurement of large resistors should pay attention to do not touch the red and black pens with both hands, not out of the danger of a little bit, but to ensure that the accuracy of measuring the resistance, touching the hands of one of the pens are can be.
Potentiometer Detection
Usually the potentiometer has three pins, first use the multimeter to select the resistance file to test the potentiometer three pins whether there are two pins between the resistance value for or close to the potentiometer marked resistance, if the difference is a lot of potentiometer has been damaged, if the normal multimeter continue to measure the two pins, and then will be rotated counterclockwise potentiometer close to the position of the shutdown, at this time the resistance value is the smaller the better, and then rotate clockwise, if the resistance is gradually increasing, rotate to the final resistance, if the resistance value is the same, the resistance value is the same. Gradually increase, rotate to the final resistance value close to the marked resistance value, then the potentiometer is normal.
Fixed capacitor detection
In addition to using a multimeter to select the capacitance block the appropriate range to measure the capacitance value can also be measured with a resistance file, the measurement should choose the appropriate resistance gear, with two pens were connected to two pins of the capacitor, the resistance value should be infinity, if the resistance value of 0, then the capacitor is damaged.
Electrolytic capacitor detection
Electrolytic capacitors and fixed capacitor measurement method is a little different, of course, you can choose to use the capacitance block to detect, this everyone will, say a few words with the resistance block to measure the method, first select the appropriate resistance gear, the red pen and the black pen were in contact with the capacitor's two poles, then the display value will be increased from 0 until the overflow symbols are shown 1, if it always shows 0, indicating that the capacitor is shorted internally, if it always shows 1 is that the capacitor is open between the poles, it is possible to choose the resistance file is not appropriate, here must pay attention to, in the measurement of electrolytic capacitors due to the positive and negative poles of the points, so be sure not to connect the reverse, usually the red pen to the anode of the capacitor (the foot of the long one), the black pen to the cathode of the capacitor (the foot of the short one), the pointer multimeter is exactly the opposite.
Inductance detection
The same choice of multimeter resistance gear, the pen connected to both ends of the inductor, if the measured resistance value of zero is the inductor internal short-circuit, under normal circumstances the size of the measured inductor DC resistance and winding inductor coils used in the enamelled wire diameter, the number of coils have a direct relationship, as long as the resistance value can be measured, can be regarded as normal inductance.
Diode detection
The multimeter to the test diode gear, with a red pen to the anode of the diode, the black pen to the cathode of the diode, if the display shows the diode voltage drop (usually 0.5 silicon tube, germanium tube 0.2) is that the diode is normal, switch the pen, if the display shows that the 1 is normal, otherwise it is broken, if the two test results are 0 or 1, then the diode has been damaged.
