Cable TV splitter

Cable TV splitter Actually, it is a directional signal transmission device (with a built-in directional coupler). There are many types, such as one-branch, two-branch, four-branch, eight-branch, etc. The splitter transmits part of the signal energy to the branch port (TAB), and the remaining signal is sent to the next splitter or distributor through the output port (OUT). The splitter has better mutual isolation and reverse isolation performance, and branch energy control (called coupling). Each type has multiple specifications. From

The coupling capacity of 4DB to 30DB can meet the needs of engineering. In home decoration, 4DB and 6DB are often used to replace two distributors, and 8DB or 12DB two distributors are often used to replace three distributors. When there are more distribution routes, or when there are changes in the demand for more routes, it is more reasonable to use a branch plus a distributor.

TV distributor: TV distributor uses the capacitor and small magnetic coil of the internal structure to make the level signal passing through the distributor appropriately weak, increase stability, and make each output port reach a certain loss standard. The second distribution is generally 3.5DB, the third distribution is generally 5.7DB, and the fourth distribution is 7DB, so that each output interface is kept at 75 ohm resistance, so that the output port maintains a normal level to receive the signal. In short, the more distribution paths there are and the longer the cable is, the smaller the signal will be. Based on the appearance of snow on the TV picture tube, a household bidirectional amplifier should be installed. The impedance of each port of the distributor should be 75 ohms to ensure that it matches the impedance of the cable and the TV. If it does not match, it will cause signal reflection, reduce the transmission effect, cause image interference, etc. The dimension indicating the quality of the match is expressed by reflection loss (DB). The larger this value, the better. Excellent products can reach more than 18DB. The branch loss is expressed by distribution loss (DB). The signal input (IN) to the output port (OUT) should be reduced through the distribution. The theoretical value is 3DB for two distributions and 6DB for four distributions.

Common products are 4DB and 8DB, excellent products are 3.5DB and below 7DB, and the output ports are isolated from each other (DB) and cannot communicate with each other to avoid mutual interference between TVs. Excellent products are greater than 30DB, and the effect obtained by using a splitter is better than that of a distributor.

The sensor can use a pyroelectric infrared sensor or a vibration sensor. The pyroelectric infrared sensor outputs an electrical signal by detecting infrared rays emitted by humans or animals, and the action angle is 110°. The BISS001 type infrared finished component can be used, and the action distance is adjusted by the Fresnel lens. The vibration sensor can use the ND-1 type high-sensitivity vibration displacement sensor. It is an all-round solid-state control device that integrates vibration and displacement measurement. It has a high detection sensitivity to vibration, suppresses the sound signal of the surrounding environment, and has a strong anti-interference ability. Its sensitivity can be adjusted by capacitance.