In the use of a television set, in addition to operating the power switch of the television set, it is also necessary to operate the power switch of the set top box, especially when the position of the set top box is inconvenient to operate, which is very inconvenient. Here is a method of linkage between a set-top box and a TV switch, which can solve this problem. This article refers to the address: http:// 1 . Current Transformer Automatic Coffee Maker,Coffee Pod Machines,Pod Coffee Makers,Instant Pod Coffee machine, Ground Coffee and Pod 2 in 1 machnie FOSHAN FORTUNE ELECTRICAL APPLIANCE CO.,LTD , https://www.coffelady.com
The circuit is shown in the figure and consists of three main parts: 
The function of the current transformer is to detect the current signal of the TV power supply circuit, which can be modified by a small power transformer of about 2 ∽ 3vA. It is recommended to find a waste household leakage switch, remove the zero-sequence current transformer inside, and then use the plastic insulated wire (the wire cross-section is determined by the working current of the TV) to wear around 20 ~ 30 作为 as the primary winding, specifically åŒThe number is not very strict, you can connect the primary winding series into the TV power supply line, and measure the secondary voltage with the multimeter AC voltage. It can be around 4V.
2 . Rectifier filter circuit
The rectification and filtering circuit adopts the simplest half-wave rectification. If the voltage supplied by the secondary side of the current transformer is low, the half-wave rectification can be changed to half-wave voltage doubler rectification. Generally, the control terminal of the small solid state relay has a current of 3 to 10 mA. It can be driven.
3 . AC solid state relay
The AC solid state relay is an optically coupled bidirectional thyristor with an AC solid state relay with a withstand voltage of 500V and a current of 1A to meet the load requirements of the set-top box.