Safe smart lock principle Basic principles and hardware components Smart lock system consists of intelligent monitoring and electronic locks. Two off-site placement, intelligent monitoring the supply of electronic locks power required to send and receive alarm and status information. Using line multiplexing, electricity supply and transmission of information sharing a two-core cable, and improve system reliability and security. The basic principle of intelligent monitoring Smart Monitor block diagram, which consists of a microcontroller, clock, keyboard, LCD display, memory, demodulator circuit multiplexing and monitoring the A / D conversion, buzzer unit. Communication between the electronic locks, intelligent analysis and safety monitoring functions of the communication line. Sent in the sender, electronic locks modulated data signal through the pulse transformer T will boost; buck evacuation demodulator at the receiving end, the pulse transformer T will receive the data signal in order to reduce the carrier signal in the transmission in the process of wear and tear. In order to reduce interference between communication and power supply, L, choke, the choice of coupling capacitor C should be considered. Set the carrier frequency fo = 400kHz, in order to ensure the vast majority of signal energy transmission to the receiving end, taking L = 33.7μH C1 = 0.047μF. Current monitoring technology In order to prevent the human destruction of communication lines and the electromagnetic actuator for some reason, resulting in current flow through the solenoid coil is too large to burn the coil current monitoring technology in the design of intelligent lock.The current monitor to MAXIM produced current / voltage conversion chip MAX471. Measured current of the chip can translate into output voltage U, and a large measurement range, high precision, the output voltage U and the measured current I is proportional to the feature. The current monitor output voltage sent to the A / D converter, microcontroller by reading the A / D conversion results, and was informed that the current changes in the lines, through the analysis to detect anomalies, an alarm signal. Smart locks take full advantage of the 51 system microcontroller software and hardware resources, the introduction of intelligent analysis capabilities, improve system reliability and security. Welcomed by the users through the installation in a type safe. In addition, the intelligent lock in a soft, little change in terms of hardware, can constitute a distributed intelligent monitoring network, centralized monitoring and management within a certain range, with a wide range in the finance, insurance, military areas and other safety precautionsapplication prospects. Intelligent monitoring is always in the receiving state, to receive the alarm and status information sent by electronic locks in a fixed format. Alarm information immediately via the LCD display and the buzzer sound and light alarm; status information will be stored in memory and the historical status of the electronic locks at this very moment ago, come to the trends, predict futurechanges in the state, through the LCD display to the staff on duty to provide appropriate information for decision-making.Establishment of communication links at the same time intelligent monitoring and electronic locks, A / D converter in real-time monitoring of flow through the communication line supply current changes, effectively preventing the damage caused by human factors, to ensure the smooth flow of communication lines.