A homemade infrared automatic door controller circuit diagram

Figure 1 shows the infrared receiving and motor driving circuit. When no one is around, the infrared receiver normally receives the infrared beam from the other side. Use a 60mm long guide tube (Figure 3) that is just inserted into the infrared transmitting tube and fix it parallel to the wall at an appropriate height and align it with the opposite receiver. In this way, the infrared rays emitted are in one beam and will not easily interfere with another receiver. The specific installation method is shown in Figure 4. After being amplified and filtered by BG6, BG7, CR, etc., it outputs a low level. At this time, BG5 is cut off, and BG2 and BG3 are turned on to perform the door closing action. When a person walks to the door, the infrared light is blocked. The high level output of BG7 drives BG1 and BG4 through one limit switch to perform the door opening action. The other channel drives BG5 through R1 to turn off BG2. When the door opens to the specified position, the door opens to the limit The bit switch is turned off so that the motor will no longer continue to run. When the person leaves, BG7 no longer outputs a high level, and the door is closed after a delay of three seconds by capacitor C1.

The transmitting circuit can be modified from the finished TV remote control (Figure 2). Remove the original transmitting tube and connect it to the prepared special transmitter with leads. Connect the two transmitters in parallel and pay attention to the polarity. Then find a suitable button to short-circuit it and let it continue to transmit, preferably the "screen display" button, in order to try not to interfere with TVs that may be in the radiation area. Use RW to adjust the transmit power to just enough to receive it.

Main component selection: The four power tubes used in the motor drive circuit are IRF9540/P type/100V/19A and IRF540/N type/100V/28A field effect tubes. Because they are driven by voltage, they consume almost no driving power. Its internal resistance is small and the temperature rise is very small. They can be installed on a small aluminum plate and pay attention to the insulation. For the motor, you can go to an auto parts store to buy a 12V wiper motor, remove its moment arm, install a four-stroke motorcycle engine gear, connect it with a few small chains, and then use a steel plate to make a bracket and fix it on the door. See Figure 5 for specific installation methods.

In order to prevent the power outage from affecting the normal use of the door, I designed a transformer to reduce the voltage and match it with a 12V battery. The main circuit uses 12V power supply and is isolated from the mains, which improves safety.