How to avoid short circuit by measuring the voltage of each line on the circuit board with multimeter
When measuring electronic components of any circuit with a multimeter, you must first check the state of the multimeter before your stylus touches the electronic components. For example, when measuring DC voltage, you must hit the DC voltage gear. If you don't know what the circuit voltage is, first of all, hit the gear to the highest gear. If you are measuring AC voltage, you must hit the relevant gear of AC. If you don't know the voltage, you should also hit the highest gear to measure it first. After reaching the highest gear to measure the data, adjust the gear as needed for accurate measurement. Remind everyone to check the state of the multimeter to prevent some people from measuring the voltage directly when the multimeter is in the resistance or capacitance range, which will cause the possibility of short circuit and burning things. Therefore, before measuring anything, we must form a habit of marking, that is, we must look at the gear status of the multimeter and make sure that it is correct before measuring.
First of all, let's answer the main question: how to avoid short circuit when measuring the voltage of each line on the circuit board with multimeter
1, as sharp as possible multimeter nib.
When I was still at school, I followed a habit of my senior brother, that is, I liked to polish the metal front ends of all my multimeters. The sharp multimeter tip can contact the circuit board area as small as possible, and the measurement of some small-area patch components can prevent the tip from being too thick to accidentally touch adjacent contacts. This way, if you are afraid that the polished pen will easily oxidize.
2. Find extra black pens and transform them into alligator clips.
Find an extra pair of pens, cut off the black one and find a crocodile clip to weld it for later use. Of course, if you don't want to do it yourself, you can buy ready-made, red and black pens.
To measure the voltage of the circuit board, first judge whether the part to be measured is DC voltage or AC voltage. If it is DC voltage, first set the gear of the multimeter and hit the gear for DC voltage measurement. Then, take a black pen in one hand and a red pen in the other. The black pens are all grounded terminals, and try to find a grounding point that is easy to put and touch as close as possible. Generally, the grounding point is a relatively large circuit board. The red pen is separated to measure the circuit to be measured. At this time, the more polished the multimeter tip, the more convenient it is to measure some fine patch component circuits. If it is not convenient for two hands to hold pens separately, the spare pens with alligator clips we mentioned earlier can come in handy at this time. Connect the black pens with alligator clips, and the alligator clips them to the grounding point of the circuit board, so that the red pens can measure the whole DC circuit at will.
If you encounter a particularly thin circuit and don't have a sharp pen tip, you can find a sewing needle and fix it on the pen tip with a thin copper wire without insulation, which can also be measured.
