48 Pages
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7,167 Words
This work is human presence activated doorbell system. When someone comes to our house and he searches for the doorbell switch and then rings it to let us know his presence. If the who came to our house cannot find the doorbell or else if the person is so short that he cannot reach the doorbell, what can be done? How will it be if we use an automatic doorbell which rings as soon as a person arrives at our place? There are no more hassl […]
ABSTRACT Today the traditional wired type of doorbells are gradually getting obsolete and are being replaced by the advanced wireless type of doorbells that are easier to install due to their hassle free set-ups. Wireless doorbell system generally comprises at least one RF transmitter powered by a battery or other power source, such as existing electrical wiring, and a RF receiver. In response to the depression of a button or other ac […]
ABSTRACT This doorbell cum visitor indicator circuit can also give identification of the visitor to your home in your absence. When you’re home, you can use it simply as a normal doorbell. The circuit comprises a monostable built around timer IC 555 (IC1), relay driver transistor BC548 (T1), inverter section built around IC 7404 (IC2), latching section built around IC 555 (IC3) and LED display driver transistor BC548 (T2). TABLE OF C […]
ABSTRACT This circuit lets one to wirelessly control an appliance from a remote place by using a wireless doorbell. The appliance is triggered by the signal from the transmitter of the wireless doorbell and turns off automatically after the preset time period. The circuit comprises a doorbell (DB1), timer NE555 (IC1) and a few discrete components. The audio output from the battery-powered doorbell receiver is connected to series resi […]
ABSTRACT The project is on a wireless electronics door bell with indicating lighting system used in places like home, shopping malls, hotels and theaters. This project proposes a system of automatic sensing any body movement object near the door. This is achieved with help of a PIR (Passive Infrared) sensor which emits infrared energy when an is sensed from a considerable distance. This sensing signal is fed to tone generator which p […]
ABSTRACT An electronic bell is a signaling device typically placed near an entry door to a building. When a visitor presses a button the bell rings inside the building, alerting the occupant to the presence of the visitor. Modern house bells are electric — they are actuated by an electric switch. In most wired systems, a button on the outside next to the door, located around the height of the doorknob, activates a signaling device (us […]
ABSTRACT This thesis is on an automatic Door Bell. When someone comes to our house and he searches for the doorbell switch and then rings it to let us know his presence. If the who came to our house cannot find the doorbell or else if the person is so short that he cannot reach the doorbell, what can be done? How will it be if we use an automatic doorbell which rings as soon as a person arrives at our place? There are no more hassles. […]