I need a Iron Sensor Circuit

[chuatc]

I need a Iron Sensor Circuit.
The circuit will be connected to a Microprocessor Board and the whole project will run as a Traffic Light System. [sig][/sig]

 

[nbucska]

What exactly do you need ?
<nbucska@pcperipherals.com>

 

I am building up a mini traffice light system using 80c31 microprocessor.

And I need to build up a series of iron sensor circuit to detect the cars that might stop at the traffic light juction. The microprocessor will then sensor-status from the sensor circuit and make its decision to run the traffic light.

So the sensor circuit logic level need to me at TTL logic level, so that it can link with my 8031 processor.

 

[nbucska]

Do you want to sense actual/full size cars or models ? To use an iron sensor for a real trafic control system may be too expensive. <nbucska@pcperipherals.com>

 

[kersing]

i'm a doing a project, and i need a iron sensor circuit to detect the water level.i'll build up a water level measement by using a microcontroller.the mecrocontroller will then sense the signal to the computer.therefore, i need a iron sensor circuit to link to the microcontroller

 

[kraigb]

I could be wrong, but I think that most of the sensors that are embedded in the intersections by traffic engineers are not much more than a tuned inductance meter. I have heard that some are starting to use microwave sensors, but the affordable and proven method is the use of inductive coils.

This consists of two coils: The first being monitored by a meter or comparator and the other inductively linked to the first coil, and used as the sensing loop.
The presence of a large quantity of iron above the sensing coil changes the flux linkage between the two coils and the difference can be detected as a voltage difference at the terminals of the first coil.

You might check this URL for more info:

http://www.sensorsmag.com/articles/0298/mag0298/main.shtml

 

[krane]

hey i also need the assembler code for using the 8031 in a traffic control system. i have tried but failed miserably... i am also using infrared sensors to detect the cars to activate the traffic light

 

[melone]

This assembly code should be trivial. I am just a little concerned that 2 people have asked basically the same exact question and don't seem to be able to give an explanation that doesn't sound like a school project. If this is NOT for school, I know that I can write any of that assembly code to show you how to do it, and I am sure that there are many other engineers in this forum that can explain exactly what type of sensors to use. However, it would be VERY inappropriate for industry professionals to do a school project!!!

If I have misjudged the scope of this project, I apologize and will do everything in my power to help.