Production of forgotten item reminder circuit

The forgotten item reminder circuit introduced to readers below was made based on this problem. This circuit actually uses the door switch to control the operation of the voice integrated circuit. The circuit is shown in Figure 1. In the figure, K1 is the switch for the taxi or bus door light L. IC1 is a three-terminal voltage regulator AN7806, which is designed to provide 6V power supply for the voice integrated circuit IC2 (UM5506). The voice integrated circuit can record, store and repeatedly play the stored voice content. Use the ⑨ pin external microphone to record the voice to remind passengers, such as "Please take your belongings and get off!" first record inside (note: the second When recording for the first time, the first recorded voice will be automatically erased).

The working process is: when the passenger opens the door and prepares to get out of the car, the door light switch K1 is closed. The door light L (note: the taxi door light is also used as a turn signal) lights up. The 12V power supply in the car is added to the IC1① pin, and passes through Ic1 After the voltage is stabilized to 6v, it is sent from pin ③ to pin ① (power end) of the voice integrated circuit. Then IC2 starts to work and sends out the voice "Please take your belongings and get out of the car!" that has been stored in IC2 through speaker Y. And it will play repeatedly until the car door is closed, thus achieving the purpose of promptly reminding passengers not to forget their belongings in the car.

R3, C2, electret microphone M and switch K2 in the dotted box in the figure are set up to record voice reminders to passengers, and can be removed after the voice recording is completed. Figure 2 is the printed circuit board diagram of the voice reminder circuit. After the components used are normal and the welding is correct, close K1 and K2 (or directly connect pin 5 of IC3 to ground), and say the words to remind the passengers again into the electret microphone. Then disconnect K1 and K2. Then close K1. Listen to whether there are cuts in the speaker before the words to remind passengers are played. If not, you need to carefully check the components and solder joints used. Generally, as long as the components used are normal and there is no problem with the welding, it can work normally when the power is turned on.

If after closing K1, the words just reminding the passengers are played from the speaker, it means that the production is basically completed. The voice recording component in the dotted box can be removed, and finally the door switch K1 can be used (you can also install another pressure sensor on the door). The switch replaces the original door switch K1) and turns on the power. Connect the speaker. Use self-tapping screws to fix the printing plate and speaker in a hidden position on the car (such as under the car seat), and the entire production process is over. If the reminder voice volume is not loud enough, you can connect another audio amplifier to the audio output of IC2.