555 fall down SOS device circuit

Published:2011/5/24 2:54:00 Author:TaoXi | Keyword: fall down, SOS | From:SeekIC

As the figure 16-29 shows, the fall down SOS device is composed of the position sensing trigger control circuit and the SOS alarm circuit. It can be used to help the critically ill patients or the disabled person. The position sensor is in the patient's chest pocket, and it is horizontal. When the patient falls down, the contact points A and B are connected by the conductive mercury, C1 charges, VT1 conducts, J1 closes, and the speaker circuit power is connected. The astable multivibrator is composed of the IC1 and R1，RP1，C1, the oscillation period T=1 second.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Signal_Processing/555_fall_down_SOS_device_circuit.html

Print this Page | Comments | Reading(3)