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  • Author Author: mcb1
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Forget Me Not : LPG Level

mcb1

This post is not really for my challenge. but struck me as being another product looking to be hacked ....image

 

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LPG Level

While I was purchasing some products in a local electronics retailer, I spotted this.

http://www.jaycar.co.nz/productView.asp?ID=QM1662&CATID=97&form=CAT2&SUBCATID=946#1

 

image

 

 

I knew Inderpreet    was looking at measuring his LPG tank, and because this was so cheap, I had to buy it.

 

I've done nothing more than opened it and take the photos. (click on them for full size)

 

    imageimageimage

The unit takes AA batteries , and the metallic portion on the rear is magnetic.

 

A closer look inside

 

  imageimage

 

It appears to have a PIC 12F675 chip which drive the two ultrasonic transducers and then the LED's and speaker when the level is low.

Just what R6 does is anyone's guess.

 

I got curious so I put it on our Bottles.

Its not extremely loud (I wasn't able to simulate the drop in level), and the LED's only briefly flash.

 

It's designed for a BBQ rather than fixed cooking bottles, but could be modified to add a small RF device.

I'm also not sure what the local insect population would make of the new home, and I'm certain it wouldn't take long for something to take up residence.

 

 

They are distributed by Electus

Electus Distribution

 

 

Enough distractions back to me challenge.

 

 

Mark

  • in reply to mcb1

    Mark sir,

    I am going to try and locate the appropriate hardware today. I think MS or SS will be easy to find and weld into configuration.

     

    Will update soon.

     

    Thanks Amd regards,

    IP

  • in reply to ipv1

    Inderpreet.

    I'd use a piece of heavy angle aluminium or metal, as the right angle, which the load cell attaches to.

    Two simple heavy duty hinges would work as the pivot.

     

    You could add a 'locator' to ensure the bottle was in the correct place (piece with a large hole that the bottom sat it)

     

    In my mind this only need to be 100-200mm above the ground, and the arc between full and empty would be very small as the load cell doesn't really compress.

     

    Mark

  • in reply to mcb1

    Mark sir,

    That's a good idea. I tried something similar with a see saw arrangement  which is a type I lever arrangement. The equation would be

    Load x load arm length = sensed weight x sensor arm length

    Now the problem is when the lengths are small, the difference or error in placement Of the bottle will cause errors.

     

    Your suggestion is however very interesting and I just might give it a go. The problem I foresee is balancing a 30kg cylinder on a platform. I am not sure what design would work in wood since anything else will be much difficult.

     

    Thanks for the idea.

     

    Regards

    IP

  • in reply to ipv1

    Inderpreet.

    I wonder if you were to make a hinged shelf to sit the bottle on, and at the hinge side at right angles, have the load cell where its being 'squashed'.

    You would loose a small amount due to the hinge, but that's easy to calibrate out.

    image

    It would solve having to use 3 cells in some form of balancing arrangement, and you could use mechanical advantage to either increase or decrease the load on the measuring cell.

     

     

    mark

  • I think sensor will work on any Steel LPG bottle...

     

    Slide this sensor on ur bottle .... at some place as per LPG level in bottle it starts giving audio feed back for low level....and It will simulate low bottle...

    If its done then interfacing transceiver is not big issue...