Wednesday, December 21, 2011

WATER LEVEL INDICATOR

Posted by Teter Doll at 8:00 PM 0 Comments

Circuit diagram:

  Parts:
Top of Form
Bottom of Form
R1,R2,R10-R12___15K  1/4W Resistors
R3,R4____________1K  1/4W Resistors
R5_____________100R  1/4W Resistor
R6______________47K  1/4W Resistor
R7,R8,R13________3K3 1/4W Resistors
R9,R14,R15_______2K7 1/4W Resistors

C1_____________470nF  63V Polyester or Ceramic Capacitor

D1_______________3mm  Green LED
D2_______________3mm  Yellow LED
D3_______________3mm  Red LED

Q1_____________BC547  45V 100mA NPN Transistor

IC1_____________4012  Dual 4 input NAND gate IC
IC2____________LM393  Dual Comparator IC

J1,J2____________Two ways output sockets

P1______________SPST pushbutton

B1________________9V  PP3 Battery

Clip for PP3 Battery

Two steel rods of appropriate length
 

Comments:
The whole project was developed on a friend's request. Its purpose was to remotely monitor the water-level in a metal tank located in the attic by means of a very simple control unit placed in the kitchen, some floors below.
Mains requirements were:
No separate supply for the remote circuit
Main and remote units connected by a thin two-wire cable
Simple LED display for the main unit
Battery operation to avoid problems related to mains supply and water proximity
As the circuit was battery operated a low current consumption was obviously welcomed
The very small remote unit is placed near the tank and measures the water level in three ranges by means of two steel rods. Each range will cover one third of the tank capacity:
Almost empty - signaled by means of a red LED (D3) in the control unit display
About half-level - signaled by means of a yellow LED (D2) in the control unit display
Almost full - signaled by means of a green LED (D1) in the control unit display
Circuit operation:
When the water-level is below the steel rods, no contact is occurring from the metal can and the rods, which are supported by a small insulated (wooden) board. The small circuit built around IC1 draws no current and therefore no voltage drop is generated across R5. IC2A, IC2B and Q1 are wired as a window comparator and, as there is zero voltage at input pins #2 and #5, D3 will illuminate.
When the water comes in contact with the first rod, pin #13 of IC1 will go high, as its input pins #9 to #12 were shorted to negative by means of the water contact. Therefore, R4 will be connected across the full supply voltage and the remote circuit will draw a current of about 9mA. This current will cause a voltage drop of about 0.9V across R5 and the window comparator will detect this voltage and will change its state, switching off D3 and illuminating D2.
When the water will reach the second rod, also pin #1 of IC1 will go high for the same reason explained above. Now either R3 and R4 will be connected across the full supply voltage and the total current drawing of the remote circuit will be about 18mA. The voltage drop across R5 will be now about 1.8V and the window comparator will switch off D2 and will drive D1.
The battery will last very long because the circuit will be mostly in the off state. Current is needed only for a few seconds when P1 is pushed to check the water-level and one of the LEDs illuminates.
Notes:
The two steel rods must be supported by a small insulated (wooden) board
IC1 and R1-R4 are mounted on a small board placed near or on the steel rods support
The two-wire cable connecting the remote circuit board to the main control board, i.e. J1 to J2, can be of any size and type (preferably thin for obvious reasons). It can be very long, if necessary.
The circuit can be used also with non-metal tanks, provided a third steel rod having the height of the tank will be added and connected to pin #7 of IC1, R3, R4 and J1.
The 4012 chip was chosen because it contains two gates and was at hand, but you can use two of the gates contained into 4001, 4011, 4093, 4049, 4069 etc. chips, provided all inputs of each gate are tied together and all inputs of unused gates are connected to the positive rail, leaving output pins open.

Share This Post

Get Updates

Subscribe to our Mailing List. We'll never share your Email address.

0 comments:

THANKS FOR UR COMMENT ....

Categories

Labels

AERONAUTICAL AEROSPACE AGRICULTURE ANDROID Android project titles Animation projects Artificial Intelligence AUTOMOBILE BANK JOBS BANK RECRUITMENTS Bio instrumentation Project titles BIO signal Project titles BIO-TECHNOLOGY BIOINFORMATICS BIOMEDICAL Biometrics projects CAREER CAT 2014 Questions CHEMICAL CIVIL Civil projects cloud computing COMP- PROJ-DOWN COMPUTER SCIENCE PROJECT DOWNLOADS COMPUTER(CSE) CONFERENCE Data mining Projects Data protection. Design projects DIGITAL SIGNAL PROCESSING IEEE Project titles Dot net projects EBOOKS ELECTRICAL MINI PROJECTS ELECTRICAL PROJECTS DOWNLOADS ELECTRONICS MINI PROJECTS ELECTRONICS PROJECT DOWNLOADS EMG PROJECTS employment Engineering projects Exams Facts final year projects FOOD TECHNOLOGY FREE IEEE 2014 project Free IEEE Paper FREE IEEE PROJECTS GATE GAte scorecard GOVT JOBS Green projects GSM BASED Guest authors HIGHWAY IEEE 2014 projects ieee 2015 projects IEEE computer science projects IEEE Paper IEEE PAPER 2015 ieee project titles IEEE projects IEEE Transactions INDUSTRIAL INNOVATIVE PROJECTS INTERFACING IT IT LIST Java projects labview projects LATEST TECHNOLOGY list of project centers Low cost projects m.com MARINE Matlab codes MATLAB PROJECT TITLES MATLAB PROJECTS MBA MBA 2015 projects MCA MECHANICAL MECHANICAL PROJECTS DOWNLOAD MINI PROJECTS modelling projects MP3 MP3 cutter Mp4 Networking topics ns2 projects online jobs PETROCHEMICAL PHYSIOLOGICAL MODELLING projects physiotheraphy Projects Power electronics power system projects PRODUCTION project centers project downloads Prosthesis projects RAILWAY RECRUITMENT 2012 Recent RECENT TECHNOLOGY RECENT TECHNOLOGY LIST RECRUITMENT Rehabilitation projects renewable power respiration projects RESUME FORMAT. Ring Tone Cutter Robotics projects. Robots in medical social network jobs Solar projects Songs Cutter Speech-music separation-Abstract structural engineering TECHNOLOGY technology management TELE COMMUNICATION TEXTILE TOP ENGINEERING COLLEGES Training VLSI

Disclaimer

This blogs is an effort to club the scattered information about engineering and project titles and ideas available in the web. While every effort is made to ensure the accuracy of the information on this site, no liability is accepted for any consequences of using it. Most of the material and information are taken from other blogs and site with the help of search engines. If any posts here are hitting the copyrights of any publishers, kindly mail the details to educations360@gmail.com It will be removed immediately.

Alexa Rank

back to top