How to prevent short circuits by using a multimeter to measure the voltage of each line on the circuit board
When measuring any circuit electronic components with a multimeter, you must first check the status of the multimeter before your test leads touch the electronic circuit components. For example, if you measure DC voltage, you must switch to the gear of DC voltage. How big, the first is to hit the gear to the highest gear. If you are measuring AC voltage, you must switch to the relevant gear for AC. If you don’t know the voltage, you can also switch to the highest gear first to measure. After turning to the highest gear and measuring the data, adjust the gear as needed for accurate measurement. Reminding everyone to check the status of the multimeter is to prevent some people from directly measuring the voltage when the multimeter is in the resistance or capacitance range, which may cause a short circuit to burn things. Therefore, before measuring anything, you must develop a number habit, that is, you must check the gear status of the multimeter, and then measure after confirming that it is correct.
First of all, let's answer the main question of the following topic: how to avoid short circuit by measuring the voltage of each line on the circuit board with a multimeter
1. A multimeter tip as sharp as possible
When I was studying and still in school, I followed a habit of my brother, that is, I like that the metal front ends of all the test leads of my own multimeters are polished very sharply. The sharp multimeter tips can contact the circuit board as small as possible. For the measurement of some small-area patch components, it can prevent the pen tip from being too thick to accidentally touch adjacent contacts.
2. Find extra black pens and transform them into crocodile clips
Find a pair of extra test leads, cut the black test lead, the end of the hand pen, and find an alligator clip to solder it on for spare. Of course, if you don't want to do it yourself, you can buy ready-made ones, including red and black pens.
To measure the voltage of the circuit board, first determine whether the part of the circuit board to be measured is DC voltage or AC voltage. If it is DC voltage, first set the gear of the multimeter to the gear of DC voltage measurement, and then take a black pen in one hand and the other hand Take the red pen, and the black pen is the grounding terminal. Try to find the 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 then separated to measure the circuit to be measured. At this time, the sharper the tip of the multimeter is, the more convenient it is to measure some fine chip component circuits. If the two hands are inconvenient to hold the test leads separately, as we said earlier, the spare test leads with crocodile clips can be sent at this time.
If you encounter a particularly thin circuit and do not have a sharp enough test pen tip, you can find a sewing needle and wrap the sewing needle on the pen tip of the test pen with a thin copper wire without insulation, which can also be measured.
