Tiny Dew Sensor
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
projectsofme
Active In SP
**

Posts: 1,124
Joined: Jun 2010
#1
18-10-2010, 01:24 PM



.pdf   Tiny%20Devices.pdf (Size: 94.19 KB / Downloads: 53)
Tiny Dew Sensor


Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. A low-cost circuit described here can be used to switch off any gadget automatically in case of excessive humidity. At the heart of the circuit is an inexpensive (resistor type) dew sensor element. Although dew sensor elements are widely used in video cassette players and recorders, these may not be easily available in local market. However, the same can be procured from authorised service centres of reputed companies. The author used the dew sensor for FUNAI VCP model No. V.I.P. 3000A (Part No: 6808-08-04, reference no. 336) in his prototype. In practice, it is observed that all dew sensors available for video application possess the same electrical characteristics irrespective of their physical shape/size, and hence are interchangeable and can be used in this project and implimentation. The circuit is basically a switching type circuit made with the help of a popular dual op-amp IC LM358N which is configured here as a comparator. (Note that only one half of the IC is used here.) Under normal conditions, resistance of the dew sensor is low (1 kilo-ohm or so) and thus the voltage at its non-inverting terminal (pin 3) is low compared to that at its inverting input (pin 2) terminal. The corresponding output of the comparator (at pin 1) is accordingly low and thus nothing happens in the circuit. When humidity exceeds 80 per cent, the sensor resistance increases rapidly. As a result, the non-inverting pin becomes more positive than the inverting pin. This pushes up the output of IC1 to a high level. As a consequence, the LED inside the opto-coupler is energised. At the same time LED1 provides a visual indication. The opto-coupler can be suitably interfaced to any electronic device for switching purpose. Circuit comprising diode D1, resistors R8 and R6 and capacitor C1 forms a lowvoltage, low-current power supply unit. This simple arrangement obviates the requirement for a bulky and expensive step-down transformer.
Reply

Important Note..!

If you are not satisfied with above reply ,..Please

ASK HERE

So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page

Quick Reply
Message
Type your reply to this message here.


Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  current sensor mini project jaseelati 0 254 09-01-2015, 02:15 PM
Last Post: jaseelati
  universal current sensor ppt jaseelati 0 173 20-12-2014, 03:42 PM
Last Post: jaseelati
  Ultrasonic Sensor Based DC Motor Control Using LabVIEW seminar class 5 5,277 05-05-2014, 10:08 AM
Last Post: seminar project topic
  Power efficient routing protocol for wireless cooperative sensor networks Report study tips 0 497 30-08-2013, 04:50 PM
Last Post: study tips
  DESIGN AND IMPLEMENTATION OF PYROELECTRIC INFRARED SENSOR BASED SECURITY SYSTEM seminar ideas 8 5,798 30-08-2013, 09:51 AM
Last Post: study tips
  Robot Assisted Emergency Search and Rescue System With a Wireless Sensor Network pdf study tips 0 627 23-08-2013, 03:22 PM
Last Post: study tips
  universal current sensor full report project report tiger 13 12,291 31-07-2013, 09:38 AM
Last Post: study tips
  Heart Rate Sensor pdf study tips 0 314 18-07-2013, 02:20 PM
Last Post: study tips
  Introduction To Wireless Sensor Networks PPT seminar flower 1 731 17-06-2013, 04:17 PM
Last Post: study tips
  Report on Touch Screen Sensor ppt study tips 0 507 12-06-2013, 11:12 AM
Last Post: study tips