Let's take a look at the working principle of the electronic circuit of this condenser microphone. Some of them are confused.

猎影影

Let's take a look at the working principle of the electronic circuit of this condenser microphone. Some of them are confused. [Copy link]

Let's take a look at the working principle of the electronic circuit of this condenser microphone. I don't understand it. The plug is connected to the sound card. The Canon connector of the condenser microphone is used as a 3-ring plug, but one way is not powered. It seems that it cannot work. Who can help explain the actual overall working method? If the 5 solder joints of the condenser microphone are not idle, what should they be connected to? This is what I drew after removing the PCB.

chunyang

There are too many errors in the diagram, and the basic circuits are not correct. Draw the circuit carefully first.

猎影影

chunyang posted on 2022-1-27 16:26 There are too many errors in the diagram, and the basic circuits are not correct. Draw the circuit carefully first.

You didn't understand it like me. I understood it a little bit. The drawing is correct. I often copied boards before. I checked this picture several times. I also saw the same board on Taobao. It was also the same circuit. Plug in the Canon, the (1 and 3) pins of the Canon, the green and black wires are grounded, and the white wire is used as the power supply and signal line. It is indeed a failure. The reasons for the failure in this circuit are described as follows.

The 1st and 4th ring plugs are powered by 5 volts on the sound card. If the green line of the 3rd pin of the Canon is not grounded, the power supply voltage here is insufficient and there is no sound output. After the 3rd pin is grounded, the power is turned on, the C7 electrolytic capacitor is short-circuited, the collector of Q1 is at a low potential, and the resistance of the B pole makes Q1 conductive. The power supply is as marked on the figure, supplying power to the C pole of Q4, and the E pole of Q4 is at a high potential, and the subsequent circuit is conductive. I still don't understand what's going on.

Second, this board is powered by 5V and connected like a Canon. This board may be used in other places without the need for the Canon 3 pin to be grounded, but I don't know what circuit can use it.

I hope an expert can give further analysis.

maychang

Posted by Lieyingying on 2022-1-28 15:27 You didn’t understand it just like me. I understood it a little bit. There is nothing wrong with the drawing. I used to copy the board frequently. I checked this picture several times. I also saw it on Taobao...

"I understand a little bit now. The drawing is correct. I often copied boards before. I checked this picture several times. I also saw the same board on Taobao, and it has the same circuit."

I understand, but I’m afraid I understand in the wrong direction. This is worse than not understanding at all.

maychang

Posted by Lieyingying on 2022-1-28 15:27 You didn’t understand it just like me. I understood it a little bit. There is nothing wrong with the drawing. I used to copy the board frequently. I checked this picture several times. I also saw it on Taobao...

There is not even a DC power supply in the picture in the first post, but they still say "there is nothing wrong with the drawing".

Fred_1977

It is divided into three stages: input stage, providing bias; intermediate stage: generating differential signal, output stage.