29-06-2012, 12:36 PM
Water Level Indicator
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INTRODUCTION
To understand the concept of computer hardware the knowledge of electronics is must. The project that I have chosen for understanding the concept of electronics is a water level indicator. Apart from begin exposed towards the working of the various parts of the electronics systems, the project has the significance that it can be used to detect the rain.
The water level indicator works on the dc voltage. The main part of the circuit is the IC 40106. Whenever the water level reaches at particular level the circuit of the IC 40106 gets completed and the IC produces the pulses. The output is displayed by glowing LED
CIRCUIT DESCRIPTION
The Water level Indicator circuit consists of three main sections:
Supply section
Sensor section
Display section
Supply Section
The supply section consists of a 3V battery voltage.
Instead one can also use a step down transformer which converts 220 V ac to 3 V ac. followed by a rectifier diode, which converts ac to rippled dc.
Sensor section
This section consists of a PCB with two resistors of 180K ohm. The PCB plate act as a sensor.
PARTS DETAIL
Resistance: Resistance is the property of the material by which it opposes the flow of current .The unit of resistance is ohms. The circuit uses 5 carbon composition resistances whose value can be found using the color coding.
Capacitor:-
Capacitor has ability to store charge and release them at a later time. Capacitance is the measure of the amount of charge that a capacitor can store for a given applied voltage. The unit of capacitance is the farad (F) or microfarad. The capacitors used in the circuit is an electrolytic capacitor. The value and voltage rating of the electrolytic capacitor can be directly read from the capacitor itself.
The electrolytic capacitor should be used with proper polarity.
In the circuit the electrolytic capacitor is used as a bypass capacitor. Any noise variation in the circuit is removed by the capacitor.
Printed circuit board:
The printed circuit board is a sheet of insulating material (bakelite) on which a copper clad coating is done. The circuit is being printed on the PCB. The circuit uses two PCB’s. On one PCB there is detector circuit. Other PCB consists of the copper strips for sensing the level of the water.
CD 40106
The level of the water is being sensed by an Integrated circuit (CD 40106).
The IC 40106 is a 14 pin integrated circuit. When the water reaches a particular level the strip gets shorted with the ground strip. The pins 1, 3, 5, 9, 11, 13 gets low signal corresponding to the six levels. The IC gets a low signal and the gives output on the corresponding LED by glowing it.