A very interesting remote controlled alarm circuit using TSOP1736. Routing of an electric cable to attach a calling bell switch near the bed of an old age/patient is not a good idea. Here is an ultra simple battery operated remote controlled alarm to help old age members/patients in bed, especially at home/hospital. Any tv/video infrared remote control handset (36Khz) can be used to arm the alarm!
How does the remote controlled sound alarm works
At the heart of the circuit is the popular integrated infrared sensor TSOP1736.The TSOP1736 is a miniaturized receiver for infrared remote control systems. PIN diode and preamplifier are assembled on lead frame, the epoxy package is designed as an infrared filter. Further, a bandpassfilter, an integrator stage and an automatic gain control are used to suppress unwanted noise disturbances.
When a person needs immediate attention of someone, he should firmly press and hold any button in the keyapad of the remote control handset and aim the handset towards the sensor (IRRX) of the alarm circuit.
Instantly, the active piezo-buzzer stars beeping in tune with the modulated infrared signals emitted by the handset. Sametime, a good visual alert is provided by the red colored 10mm LED(D2).
After construction, enclose the whole remote controlled siren unit in a transparent cabinet with the Infrared sensor at the front side of the box. Now power the circuit through a suitable 9V compact alkaline battery. Insertion of an ordinary on/off toggle switch in the positive rail is a good idea. After successful testing, mount the unit in a proper point at the wall of the room/hall, as per the requirement. Finally, the lab prototype is connected to a multidirectional 5V dc buzzer. However, you can use an ordinary 5V dc buzzer or any kind of 5V active sounder.
