Grid disconnection alarm circuit diagram

The circuit working principle of this device is shown in Figure 13. When the wire mesh Fe is intact, the ① and ② pins of LSE are in collusion, and its ④ pin outputs high level, the transistor VT is cut off, the relay J is in the released state, and the alarm does not work. If the barbed wire Fe is cut (any section), the ① and ② pins of LSE are equivalent to open circuits, and its ④ pin changes from the original high level state to the low level state, and the transistor VT is turned on, thus causing the relay to J excitation is closed, its normally open contact j is closed, and the power supply of the alarm circuit is turned on , so the alarm sounds.

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