We need to get this for our project.. it's only a part of the project. This O/P goes to the microcontroller and so on..
So the question is..
1. Is such a thing avble commercially? OR
2. Can we design using circuits??
3. OR .. Can it be done this way??

From the figure, the magnetic float is a permanent magnet, while the magnet that is connected to external circuit is an induced electro - magnet.
We have the arrangement in ,say (NorthPole-NorthPole arrangement), thereby they repel, but how to sense the change, for eg. in current change proportions etc.. ???
IS this above thing possible at all??

 

Why not use a magnetic reed switch at the top and tap there to the uC?

Or are you tring to get the increments of the levels. I think that might be what you are after. Maybe switches on the inside of the tube? Bounce a signal off the top of the liquid from the top of the tank.

 

the arrangment shown above will not work since u r using permanant magnets . if u need continous variation try considering flot type system.
or a transformer with moving core type design.

 

I accept your suggestion .. yes What u r suggesting is like a magnetic proximity sensor provided here..
yes.. but then let's look at it realistically .. Say a 5 litre fuel tank.. How many reed switches can I keep atmost? probably 5 - 10 , I thought of something on lines of xx.x (Digital O/P) for fuel level .. Is that possible using the reed switches??

 

Can you enlighten me more on this topic, akg??
I'd love it ... Thanx!

 

off the shelf level measurment with switches in a tube with a floating ring magnet with varying switches per foot of tube, other ways are to use a capactance sensor but they are mostly on or off type of switch. a variable reluctance transformer with a float ( Dancer control ) or just use a weigh type system for a linear sensor output.
joe

 

mrmmani22

What you are proposing will not work, two permanent magnets will not do anything very much in a fairly static situation like a fuel tank.

Something similar has been discussed here some time ago, the idea was to use reed switches in a tube and have a floating magnet around the tube operating the switches.
Here is a link to that thread:
http://www.electro-tech-online.com/v...ghlight=magnet

Have a look and see if that give you any ideas.

JimB

__________________
Experience is directly proportional to the value of the equipment ruined.

 

Just salvage a float one from a car dump. Most use a float arm with a potentiometer to judge fuel level.

__________________
Mark Higgins

 

There is a common type of sensor that is just a metal rod going into the tank. You measure the capacitance by using it as the timing capacitance for a 555 and count the frequency output.

It doesn't work with water, only fuel. The presence of alcohol in fuel (a common blend is 10% nowadays) will throw off the reading substantially though.

__________________
I thought what I'd do was I'd pretend I was one of those deaf-mutes.

 

Look up linear transformer, it will give a linear analog output.

__________________
see my website: www.geocities.com/russlk

 

hi

i recently posted a similar question and here is what i have got to work

http://www.allelectronics.com/cgi-bi...ALARM_IC_.html

L4620

also some other ICs that may be used, QT114, QT301 etc.

- sz

 

hyedenny

hi
BMW coolant level sensors are constructed with a floating ring which has a magnet and actuate a reed switch which is in the middle of the assembly. They are easily available from any decent auto parts store.

 

I still like your original idea. Just add magnetic reed switches in the rod and feed them to a micro-controller. Simple. Affix magnet to the float, and let the switches signal the micro by tripping as it goes up and down.

I am going to look at the liquid alarm IC scorpioz mention..

 

Some boats use a sender with a lot of magnetic reed switches and a resistor in series between each one. The switches close the circuit at whatever level using all resistors from the top down to that level. Low resistance at top, high at empty having to go thru all resistors.

 

Can you explain this idea please?