Traffic Light Sensor

[Marcus]

Hi guys,

I'm looking for a suitable sensor for my Traffic Light Controller System.
The sensor details are as follows:
- Detect metal objects "like a metal toy car" at any range.
- Produces analog/digital output to the FPGA Board.

My research suggest that I use an Induction sensor. I searched the forums already:
http://www.cytron.com.my/viewProduct.ph ... e%20Sensor
http://www.cytron.com.my/viewProduct.ph ... e%20Sensor

However, I am not sure of whether this sensor would be suitable for my application. Hope to get a response on
the suitable sensor offered by Cytron or any other related suggestions.

[yonghui]

what do u meant by at any range?

[robosang]

What the use if the sensor can detect car at any range?

There is no such sensor

[Marcus]

Well since I'm making a model out of this TLC, I would prefer a sensor which would detect
vehicles at the range of 10mm at least.

Any suggestions?

[Marcus]

Can anyone here help me out?

[shahrul]

You read the product page you give 1st post. The first sensor sensing range is 4mm, the second sensor sensing range is 8mm. So, it's meet your requirements or not? If you want atleast 10mm, both sensor can't use.

[Marcus]

But it provides an NPN output signal? What is an NPN output signal? Can it be used for ALTERA DE2 Board?

[shahrul]

But it provides an NPN output signal? What is an NPN output signal? Can it be used for ALTERA DE2 Board?

If NPN output, the signl sensor is sinking. To working it, you need to put pull-up resistor.

[Marcus]

Ok. So once I connect it to a pull-up resistor, it will be "1" isn't it? What's the expected output voltage for
this NPN signal?

[shahrul]

Ok. So once I connect it to a pull-up resistor, it will be "1" isn't it? What's the expected output voltage for
this NPN signal?

Output voltage depends on your pull-up. If you pull-up to 5V, the output is 5V or 0V. If you put pull-up 12V, the output is 12V or 0V. That's why NPN output is easy to compatible with any voltage level.