1. TOUCH PAD BASED BULB INTENSITY CONTROL
ABSTRACT
In this process keypad places an important role. As the old keypad have many disadvantages
like application of pressure on the keys and its mechanical ruggedness and so on. As we
know there have been many other keypads that have come in to existence later out of which
the latest keypad is a touchpad. Touchpad is one which can be used to control the devices by
just touching a switch.
Light dimming is based on adjusting the voltage which gets to the lamp. Light dimming has
been possible for many decades by using adjustable power resistors and adjustable
transformers. Those methods have been used in movie theatres, stages and other public
places. The problem of those light controlling methods have been that they are big,
expensive, have poor efficiency and they are hard to control from remote location.
In this project we can set the bulb intensity as we required by using touchpad. That means
bulb will glow very brightly when the firing angle of triac is less and bulb intensity will
decreases as the firing angle increases and the status of the project will be displayed on LCD.
The main goal of this project is to control the intensity of bulb using touchpad. By just
touching keys on the touch pad we are going to control the intensity with the help of logic
IC’s. As a part of this project we are designing the touch pad with the help of the Logic gates.
These are going to respond on the resistance of the human body. By using these switches we
may extend this project to any application like appliance control, password protected devices
etc.

2. BLOCK DIAGRAM