| 摘要 |
The alarm device for scaring off intruders consists of a current source (10) which supplies the sound generator (14), the bell (12) and the control device (16). The doorbell button (18) switches on the bell (12). At the same time, the control device (16) receives a pulse via the two lines (20) and (22), which causes a relay to pull in the control device (16), so that the line (24) is closed and the sound generator (14) which imitates the barking of dogs is switched on. After a specified time the control device (16) turns off the barking. <IMAGE>
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