circuit analysis:
1. This circuit is a row selection circuit that selects and drives the corresponding row. The 4953 chip plays a magnifying role.
2. The circuit is a 1/4 scan circuit. It can be seen that the A, B, C, and D signals from the HC245 chip are not directly connected to the 4953 chip through the 3-8 decoder, indicating that the entire circuit does not have a 3-8 decoder, and the circuit uses A, B, and C. , D a total of 4 signal lines to do the line selection. When the A signal is valid, 4 lines are selected. Similarly, when the B, C, and D signals are valid, 4 lines are selected. Scanning 4 times completes one cycle, so it is 1/4 scan. Change the angle to understand the scanning mode of the circuit. The circuit controls a total of 16 lines, sharing 4 signal lines for selection, so 4/16=1/4. So it is 4 scan circuits.
3, the circuit shows that the implementation of the scanning mode does not have to use a 3-8 decoder. It is not like a lot of information, as long as there are A, B, C, D signals in the interface definition, it is 16 scanning mode. To determine what scanning method is, look at the A, B, C, D signals, but also to see if there is a 3-8 decoder. If there are A, B, C signals, and a 3-8 decoder, it is 1/8 scan mode. If there are A, B, C, D signals and there are 2 3-8 decoders at the same time, it is 1/16 scan.
Speaker Earpiece Anti Dust Screen
The speaker earpiece anti dust screen is the dust screen cover on the speaker or handset, so it is also known as the speaker cover. It is generally used in mobile phones, computers, cars, Bluetooth headsets and other sound generating devices. A well-ventilated speaker dust screen ensures that dust and dirt are effectively kept out of the device, ensuring the quality of sound transmission. It also ensures that the device is well ventilated under changing environmental conditions and avoids damage to the housing seal caused by increased internal pressure, which can expose sensitive electronic components to water and dust. Mobile phone speaker mesh and traditional speaker mesh materials are mostly stainless steel, PVC, etc. The metal dust screen also has a strong protective effect and can withstand strong external forces, which is relatively safe.
We customize our earpiece dust screen according to the drawings provided by our customers. The raw material we use more often for dust screens is stainless steel. We can achieve a thickness of 0.3mm and are equipped with professional metal etching equipment and exposure development equipment to ensure that our earpiece dust screens have uniformly arranged holes, consistent apertures (200,000 mesh per panel) and a smooth surface without fine holes.
Speaker Anti Dust Screen, Earpiece Dust Screen, Speaker Mesh, Metal Dust Screen, Dust Screen
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