how to use ugn3119u hall effect sensor

hi, i want to make a tachometer with ugn3119u hall effect sensor, pin diagram is like this


how can i use this open collector output, i want to get logic 1 pulse when magnet comes near sensor... thanks for help

This is a circuit i used for a tacho on a diesel engine with a magnet on the crank pulley in a marine aplication. Second pic is calibrating it using 50Hz AC on a small soenoid coil to drive the Hall sensor.

i just want to get logic output when magnet comes near, i dont want to put the sensor on motor driver, i'll use mcu, i tried pull up resistor and some other things they dont work, what kind of circuit i must design?

Using a pullup resistor in the circuit shown works & gives a pulse. Only one side of the Hall device is sensitive to magnetic fields. It needs to see a Nth pole then a Sth pole to switch it on/off.

i have 5v supply, i read 0.8 to 0.3v output when i use 10k pull-up, output changes all time, magnet doesn't even effect output voltage, i tried 2 different sensors, they're not broken

cemdogusyucel@hotmail.com said:

i have 5v supply, i read 0.8 to 0.3v output when i use 10k pull-up, output changes all time, magnet doesn't even effect output voltage, i tried 2 different sensors, they're not broken

Click to expand...

Many Hall sensors are pole dependent, try turning your magnet over. If you have the N pole to the sensor, try putting the S pole to it.

Also the magnet must pass over the "sweet spot". This is shown in the data sheet for the sensor.

Post the complete circuit you are testing.

output with 10k pull-up worked, i see that i put magnet's wrong pole,

Many Hall sensors are pole dependent, try turning your magnet over. If you have the N pole to the sensor, try putting the S pole to it.

Also the magnet must pass over the "sweet spot". This is shown in the data sheet for the sensor.

Click to expand...

what's sweet spot?

On the data sheet it shows the different packages that the chip is made in. Each one of them has a small shaded box drawn on it, with dimensions from the edge of the package. The center of that shaded box is the center of the actual sensing part of the chip. The magnet must pass that spot to get a reading. That makes that shaded box the 'sweet spot'. A slang word for the most sensitive place.