Why Flashing LED Doorbell?

Actually, I do not know also.. hahahaha... Kidding aside, there were many things that I want to do. Many gadgets I want to make. But as days passed by, I had an observation around my environment and noticed that the people inside the offices, houses or other closed establishments are not well aware if there were guests outside knocking on their door, because they are too busy in what they are doing. For certain way in order to get their attention a loud sound and a simple light must be sensed by them. So I decided to make a doorbell, a doorbell that is unique, a doorbell that is colorful and simple but most of all, a doorbell that is efficient. Il know that doorbells make sounds, but in my case, I don’t limit the capability of my doorbell only on sound, but also it creates light for the deaf to know that the doorbell operates and runs well. By applying my abilities in electronics and by doing some research work, I came up with this circuit. I made a simple doorbell circuit that would benefit the audibility of a person that can hears a sound of a doorbell and for the deaf which cannot hear the doorbell’s sound but can see a light in order to know that it is functional. I went to an electronic shop to know if the materials are available. But sadly, the first electronics shop that I went to doesn’t have any 4001 IC. Because of my ambition in this project, I went to another store. Luckily, that IC is already available and I bought it right away. Using ORCAD, I simulate my circuit. I didn’t have any problems encountered in simulating my circuit because the materials of my circuits are already available in the ORCAD library. I named this project as a Flashing LED Doorbell because I used some LED to add light and color to this Flashing LED Doorbell. This series of LED’s made the flashing Doorbell unique because most of the doorbells don’t use LED. When the push button is operated, the buzzer will sound and the LED’s will begin to flash. For the hearing members for the household, the buzzer acts as a regular doorbell. It also reassures the visitor that the doorbell is working. I used a capacitor that has small value to make my LED light and flashes whenever the buzzer is pressed and turns off whenever it is released. The length of time that the LED lights, depends on the capacitor that is used.

There were so many related projects and concepts that I have encountered in researching the design of a doorbell. The Doorbell for deaf is the most related concept in my project. This circuit provides a delayed visual indication when a doorbell switch is pressed. In addition, a DPDT switch can be moved from within the house which will light a lamp in the doorbell switch. The lamp can illuminate the words "Please Wait" for anyone with walking difficulties. The circuit uses standard 2 wire doorbell cables or loudspeaker wire. In parallel with the doorbell switch, S1 is a 1N4001 diode and a 12 volt 60mA bulb. The bulb is optional, it may be useful for anyone who is slow to answer the door, all you need to do is flick a switch inside the house, and the bulb will illuminate a label saying Please Wait inside the doorbell switch or close to it. The double pole double throw switch sends the doorbell supply to the lamp; the 22 ohm resistor is there to reduce current flow, should the doorbell switch, S1 be pressed while the lamp is on. The resistor needs to be rated 10 watts, the 0.5 Amp fuse protects against short circuits. The other related concept that was much closer to a doorbell was a fire alarm. The fire alarm was similar to a doorbell because by its function it notifies the building occupants to evacuate in the event of fire or other emergency, report the event to an off-premises location in order to summon emergency services, and to prepare the structure associated systems to control the spread of fire and smoke. The fire alarm also evolved into the technology age. The design also evolved from a simple bell to a wired system technology. Doorbells were invented to notify the host that the visitor has arrived on the premises. Sound range and quality were not introduced until the advent of electricity and technology age. In the early 90’s, the doorbell evolved from a bell tied on a rope to a wireless doorbell. A doorbell is a signaling device typically placed near a door. Most doorbells emit a ringing sound to alert the occupant of the building to a visitor's presence, when the visitor presses a button. Doorbells have two systems: the wired system and the wireless system. In most wired systems, a button is used to activate a signal device inside the building. A single pole, single throw switch momentarily clo12ses the circuit. The terminal of the button is wired to the terminal of a transformer. The transformer steps down the 120-240 volt AC power to a voltage of 10-20 volts. The other terminals of the transformer are connected to one of the three terminals on the signaling device. Another terminal is connected to a wire that travels to the other terminal on the button. After that, the transformer being energized constantly does consume a small amount of standby power constantly. The wireless system uses a button that is also located near a door that activates a built-in transmitter. The transmitter sends a radio signal to the doorbell receiver inside the building. When the radio signal is detected by the receiver, it activates the doorbell.

Circuit Diagram using Orcad