Mine sound machine small

1. Mobile phone games, mobile phone kits,
battery maintenance. If you find more new battery managers, install battery housekeepers after downloading, there are many power saving modes to save the power of mobile phones, and the intelligent dynamic adjustment of CPU frequency can save energy and power, and maintain the function of charging. It can save charging time, rece power consumption and prolong battery life in three different charging stages.

2. 5.1 is two main channels, two surround channels, plus a middle channel and a subwoofer, which can create a ready-made all-round sound, while 2.1 is two main channels and a subwoofer,

3. The volume of sound is often the radio station received, and the current intensity is not large. If the current reaches 5mA, it's very loud
furthermore, if the earphone needs to match the circuit, it's better to find a military earphone. 3000 Euro

4. Ore radio works entirely on the electromagnetic wave energy received by the antenna. The electromagnetic wave energy received by the antenna has a great relationship with the size of the antenna. Generally, the antenna should be placed when it is used. If there is an efficient antenna (made of magnetic rod), the volume can be smaller, but the smaller the better.

5. The key is that the output impedance of the circuit matches the impedance of the headset, so as to achieve the best transmission efficiency and make the sound loud
without considering impedance matching, simply adding a transformer (i.e. impedance converter), in fact, the transformer will lose a lot of energy, and it is more difficult to make a noise
a larger antenna is right, and a good ground wire is also very effective
it is suggested to learn more about ore machine in the mining instry. It's a lot of fun< br /> http://www.crystalradio.cn/

6. As shown in the figure, if the copper sheet B and copper sheet a of the component are connected to the circuit, when the slide e rotates clockwise, the length of the resistance wire becomes shorter, the resistance in the circuit becomes smaller, the current becomes larger, and the volume of the radio increases

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8. Four kinds of equipment can be realized
four kinds of equipment: antenna 10 meters thin copper wire (the old transformer can be removed from the enameled wire), 2ap9 diode, 1000 PFA capacitor, a pair of high resistance headphones
the antenna crossbar is set under the eaves (avoid vertical, prevent lightning), and led indoors, connected to 2ap9 positive pole. The negative pole is connected to the earphone, the capacitor is connected in parallel with the earphone, and the other end of the earphone is connected to a ground wire, which is connected to a nail nailed into the ground
this is the original ore radio, except that the ore is replaced by 2ap9
after the connection is correct, you can listen to the local FM station. Only one receiver, no tuning part is needed.

9. The simplest ore radio only needs a diode, a variable capacitor and a headset. I played it when I was a kid.