Automatic door control circuit

The entire controller consists of three parts: open, close, and stop signal control, protection circuit, and drive circuit.

The opening, closing and stopping of the telescopic door are controlled by connecting the D flip-flop CD4013 into a bistable circuit. When the machine is just turned on, the power acts on the R terminal of IC1-1 through the capacitor C3 and the diode VD11, so that IC1-1 is set to "0", that is, Q is "0". When opening the door, press the switch S1, so that the S terminal of IC1-1 is "1", the circuit flips, and Q is "1", and the output high level passes through the drive circuit to open the door. When the switch S3 is pressed, the high level passes through the diode VD11 to the R terminal of IC1-1, and the circuit is set to "0", that is, the Q terminal of IC1-1 is "0", and the motor stops through the drive circuit. In order to make the operation stable and reliable and prevent false triggering, three additional circuits are added here: (1) Three groups of electronic filters composed of R1, C1 and VT1, C4, R15 and VT6, C8, R25 and VT8, to prevent jitter and network interference when the switch is pressed. (2) When the door is opened to the specified position, the reed relay S4 is energized, and the high level of the output reaches the S terminal of IC5-1 through the electronic filter, causing IC5-1 to flip, and the high level of its output Q terminal acts on the R terminal of IC1-1, causing IC1-1 to reset to "0". The Q terminal of IC1-1 is "0", and the motor power is turned off through the drive circuit. At the same time, the high level of the Q terminal of IC5-1 passes through the NAND gate IC4-1, causing the output of IC2-1 to be "0", so that the door opening switch S1 loses its function, that is, when the door is opened to the specified position, pressing the door opening switch S1 again will no longer make the telescopic door move, thus avoiding damage to the door. (3) An AND gate IC3-1 is also installed between the Q output of IC1-1 and the input terminal of the drive circuit. Its function is that the output of IC1-1 is only valid when the door closing action is not in progress, that is, the telescopic door can only open or close at the same time, thus ensuring the reliability of the action. The signal transmission and control process of closing the door is similar to the process of opening the door.

To ensure the safety of the operation of the strong power part, this circuit is designed with two sets of protection: (1) One end of the dual-input AND gate IC2-2 is connected to the D end of IC1-2. The purpose is that only when D is "1" (that is, the Q output of IC1-2 is "O"), S1 is pressed to be effective, and IC1-1 can be turned over, to prevent IC1-2 from pressing S1 to open the door when it is closing the door, and the three-phase AC power is added to the motor again, causing an AC short circuit. (2) For the safety of the motor, a timing circuit is installed in the circuit. If the door can be opened to the specified position in 1 minute under normal circumstances, the timing time is also set at 1 minute. The signal output from the Q reverse end of IC1-1 and IC1-2 at the start of opening and closing is mixed by the AND gate and sent to the R end of IC6 (CD4060) as a timing start signal. The signal after the delay output of Q14 is used as the stop signal of the system. This can avoid the continuous rotation of the motor due to accidents and damage to the telescopic door.

The driving circuit is mainly composed of VT3, VT4, VT5 and intermediate relay. The opening and closing signals outputted in front are driven by VT3 and VT4 to drive the intermediate relay, and then drive the three-phase relay of the motor to open or close the telescopic door. The switch signal is simultaneously controlled by VT5 after passing through the OR gate composed of VD1 and VD2 to drive the warning light or send out the warning signal of opening or closing.