| 摘要 |
Baby alarm with detector (4) which consists of a series of AGC circuits (6), frequency to OC-voltage converter (7), comparator (8) with frequency references (9), a number of frequency bands going through time integrators (10) and bistable multivibrators (11) connected to a decoder (12) adjustable through the switch (13) and activatable to the alarm. The detector (4) activates the alarm on the basis of the frequency content of the inbound acoustic signal from the environment. As a consequence an adjustable threshold, which determines the sensitivity and reach of the alarm, is not necessary, and the switch (13) can be used to choose individual frequency bands corresponding to the babble, crying, and cries of the baby.<IMAGE> |
