Password lock It is a kind of lock, which is opened by a series of numbers or symbols. The password of the password lock is usually only an arrangement rather than a real combination. Only one rotary table is used for some password locks dish Plate or cam rotation; Some password locks rotate a group of dials engraved with numbers to directly drive the internal machinery of the lock.

Working principle and hardware composition of intelligent password lock

The system of intelligent password lock is composed of intelligent monitor and Electronic lock With composition. The two are placed in different places, and the intelligent monitor supplies the electronic locks Power Supply And receive the alarm information and status information sent by it. The line multiplexing technology is adopted here, so that the power supply and information transmission share a two core Cable The reliability and safety of the system are improved.

Basic principle and composition of intelligent monitor

The intelligent monitor consists of MCU, clock key Panel, LCD display, memory, demodulator, line multiplexing and monitoring, A/D conversion, buzzer and other units. It mainly completes the functions of communication with electronic locks, intelligent analysis and safety monitoring of communication lines.

At the sending end, the electronic lock passes the pulse transformer T sends the modulated data signal after boosting; At the receiving end, the pulse transformer T depressurizes the received data signal and sends it to the demodulator to reduce the loss of carrier signal in the transmission process. In order to reduce mutual interference between communication and power supply, the selection of choke L and coupling capacitor C should be considered comprehensively.

Let carrier frequency fo ＝ 400kHz. In order to ensure that most of the signal energy is transmitted to the receiving end, take L ＝ 33.7 μ H? C1＝0.047 μ F。