Can the multimeter diode gear light the diode?
There is a diode gear on the multimeter, which can be used to detect the diode and light the diode. But lighting is not absolute, there are two main reasons: 1) the diode gear voltage of multimeter is low; 2) The working voltage of LED is high.
The voltage of the diode gear of the multimeter is generally about 3V, which can light up ordinary light-emitting diodes. When measuring the quality of the diode, you can contact the positive electrode of the LED with a red stylus, and connect the black stylus with the negative electrode of the LED. When the LED is on, you can judge that the LED is good. However, some meters can't light the LED or can only light it slightly when the output voltage is low. I have used a cheaper multimeter of Youlide before, so I can't light the LED, and the diode gear is basically useless, which is very inconvenient.
LED is a special kind of diode with forward turn-on voltage drop, and this parameter is quite different. The turn-on voltage drop of LEDs with different colors is different. Generally speaking, the turn-on voltage drop of red LED is the smallest, which is about (1.5-2) V; Green is next, around (1.8-2.5)V; The pressure drop in blue is the highest, about (2-3.5) V. Therefore, the brightness of the same watch is different when measuring LEDs of different colors. Generally, red is the brightest and blue is the darkest. Even some colors can't be lit.
Matters needing attention in purchasing and using multimeter
The so-called pointer multimeter, that is, using the pointer swing angle to display the corresponding numerical value. At present, there are few in the market in pointer multimeter, and the most classic one is the MF47 pointer multimeter, which is popular among people. Pointer multimeter uses a pointer to indicate the indicator. Although reading is not very convenient, it can judge the quality of components according to the deflection angle of the pointer.
digimer
The so-called digital multimeter, that is, with an LCD screen, can directly display numerical values. Digital multimeter is the mainstream instrument now, which is more convenient to read and more intelligent. Various values of voltage, current and resistance are directly displayed on its LCD screen, which is clear at a glance. And some digital multimeters can automatically select the range without distinguishing gears.
