แก้เสียงรบกวนเข้าวิทยุรถยนต์ ง่ายๆ(สูตรลับจากช่าง)

Hello everyone, welcome to the ZimZim DIy channel. Today, we'll be presenting a simple method to eliminate noise from car audio systems. First, let's understand the cause. Noise that enters the audio system is a high-frequency wave that flows through the 12V positive wire from the alternator into various parts of the car. How do you know it's a high-frequency wave? It's easy to tell when you turn on the audio system before starting the engine, no noise enters the speakers. You can listen to music as usual. But when you start the engine, the noise immediately enters the speakers. The louder the volume, the louder the noise gets. Now that we know the cause, let's move on to the solution. The solution is to eliminate these high-frequency waves. In the electronics world, anyone who has studied electronics knows that there is a device that can filter out these unwanted frequencies and reduce signal vibration. This is called a capacitor. In addition to storing and discharging charge, capacitors also trap frequencies. The higher the frequency, the more current flows through the capacitor, ultimately leading to ground. Once we know the advantages of capacitors in this respect, we can use them to bridge between the power and ground. In this video, we'll be looking at a car stereo. Notice that there are three wires going into the radio: red, yellow, and black. Let's see how to connect the wires from the top of the radio body. The black wire is the normal ground, so you can connect it directly to the negative power supply. The yellow wire is the constant power supply to the radio. It stores various settings, such as bass, treble, and left and right volume, so they don't get lost. Therefore, it requires a direct 12 volt positive supply. The red wire requires a positive 12 volt supply to operate. It usually waits for a signal from the ignition switch to turn to the on position before the audio system will activate. Where should the capacitor be placed? It can be placed anywhere before the power cable goes into the radio. It can be bridged. But I noticed that there was a box before the radio. Could it be a signal blocker? Without delay, I immediately opened it and found that the yellow wire was connected through a fuse, a coil, and a capacitor across the positive and negative voltages. Oh, there's a noise suppression system, isn't there? So I traced the red wire and found that it was connected solely through a fuse. There was no noise suppression at all, which caused the noise. After realizing there was no capacitor on the red wire, I soldered the negative and positive terminals of the red wire. I'll use a 25V, 1000uf capacitor because the higher the microamp value for the power supply, the smoother the output. That's it! I hope this method is useful for everyone. Goodbye!