The crime prevention bell device that I produced about 20 years ago works still in the active service. It worked many times to make the thief not operate well and not go into it. The bell keeps ringing generally though the bell rings as for the crime prevention buzzer when the thief was about to enter. With this, after the fixed time, it is stoppe
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d because surroundings are troubled you and it is inconvenient. In addition, to operate even by degrees how many after it stops, the crime prevention buzzer is set again. However, because the timer had not been found to be suitable at the production this time, multi range timer ATC12112 of National was adjusted to five minutes of the turning on mode and it used it. Recently Because it had come to be able to use the PIC microcomputer, the timer of this ATC12112 was replaced with PIC12F629. It introduces it because it easily made it to good. The schematic diagram displays only an alternative part of multi range timer ATC12112 of National. Please see the page of the design and the production of the crime prevention bell device about the entire circuit. The seventh terminals (similar below the terminal number ATC12112) are connected with the power supply of +12V with the schematic diagram above. The eighth terminals are connected with the power supply side of the relay for the crime prevention buzzer. The first terminal is connected with the power supply side of +12V of the warning bell. The relay for the crime prevention buzzer is turned off if the thief enters and warning rings, the 1st 12V hangs in the terminal, the voltage of about 5V hangs in PIC12F629 in the constant voltage circuit of R1 and D1, and PIC starts. The pin is the fourth input terminal of PIC for the switch of the time of the timer. It is three seconds in L...
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