判斷開關電源上的光耦好壞？原來用一個紐扣電池，就能立馬知道 #我愛電器維修

Optocouples are mostly used in power supplies but after he broke Unlike some other originals that have obvious burnt marks For example, if the capacitor appears, it will bulge. after it breaks After the resistor burns out, it will appear that it is burnt. And when the chip is broken, most of them will explode. But after the optical puppet is broken You can't tell from the outside After the optical puppet breaks down How can we accurately judge whether it is good or bad? Today I will share with you a method In fact, it uses a button battery can quickly identify the light couple is he good or bad And this method is also very simple Let's see first Here's another board that also has a light couple on it So what? This light puppet It is used more in the circuit There is a small dot on each light couple There is a small dot, this is his first corner this is the second corner this is the third corner this is the fourth corner The order is like this Take care that the first corner is his positive input The second corner is his negative input Then let's take a look at his internal circuit diagram with rounded corners This is the first angle, the second angle, the triangle and the four angles one corner and two corners Inside is a light emitting diode The triangle and four corners are connected to a bright triode One corner is the anode of the LED The two horns are his negative pole how does it work is to give this light-emitting diode After supplying a voltage This diode will light up then this What happens after the bright triode receives its light? triangle and four corners will conduct What about measuring the quality of the halo? Usually when measuring on the board not so accurate What is the most accurate way? So take it down and measure it This is more accurate What about him? I've already disassembled one. This is the light couple of 817 Light puppet, his color is black Some are white It's actually a different color But his structure and principle are the same We put the watch on the diode gear Then connect the red pen to the first corner Connect the black test lead to the second corner It is positive to positive and negative to negative to measure Look at this watch, it will show There is more than one pressure drop There is pressure drop It just means that his internal The luminous gas pipe is already lit. So he has pressure drop Then turn the test lead back to measure You see, there is no response so that we can judge The light inside this tube is a good one Because it can be realized as forward conduction reverse cutoff It just means that the first part is good. and then the latter How to measure the quality of the phototransistor Even if the watch is still the same, adjust it to the beeping position Then measure like this If the watch does not respond See no conduction and no response You can roughly judge that he is a good person. But I can't judge This method is not so accurate So what is the most accurate way? that's right give this Give him the first and second corners of the light puppet Connect to a 3 volt power supply Just hook it up to this light couple how about this Use the netlist to measure the two leading angles again Let's listen to the netlist Listen to the triangle and the four corners and it will be connected, right? What about when you don't call him? Triangular and four corners cannot be connected Give it electricity and it will be turned on From this, it can be accurately judged that This light puppet is a good one So when measuring the optical couple, use width and width Button battery this method is very simple and easy to use