Encodable digital lock circuit diagram

This coded digital lock is suitable for electronic locks that require dedicated personnel to operate the equipment, control the power supply, or be used as a special anti-theft door.

The core IC1 of the digital lock uses programmable processor 16F84-04. The password of the digital lock consists of 6 digits, and the original code is "123456". The keyboard consists of 12 keys "0-9", "*" and "#". After installing the digital lock, you can change the password yourself. For example, if you want to change the original code to "664321", first type the "*" key, then the "#" key, and then type the above numbers in sequence. After one second, The entered 6 digits are stored in the memory, and then the 6 digits are typed again. If the keystrokes are exactly the same, the buzzer Bz1 will make a "beep" sound, indicating that the new password has been confirmed and the old password has been cancelled; if The inputs before and after do not match. Bz1 will make three consecutive beeps, indicating that the input is incorrect and the correct password needs to be re-entered. To open the digital lock during use, if the number entered is wrong, Bz1 will make three rapid beeps. Once the wrong code is entered four times in a row, the digital lock will not accept any number input for one minute and sound an alarm. , to prevent attempts to steal passwords by trying to enter them multiple times and play an anti-theft role. Press the "*" key twice in succession to eliminate the alarm sound. Press the "*" key again to return the digital lock to its original standby state.

The digital lock has two output ports K2 and K3. Connect the jumper to JP1, K2 outputs a logic level signal, and the RAO terminal of IC1 is placed at low level during standby: if the correct password is received, RAO outputs a 5V high level control signal. K2 is the extended control function port. Connect the jumper to JP2, and the RA1 terminal of IC1 outputs the switch control signal to T1, drives the relay CJ1, and controls the servo mechanism circuit connected to the K3 port.

The digital lock can use a DC power supply of 8-15V. The circuit in the picture is powered by a DC 12V power supply. The circuit standby current is 2.5mA. In order to facilitate assembly, the microprocessor main circuit board and keyboard circuit board are made into two boards, and the K4 and K5 sockets are connected through 7-wire flat tape wires.