I have seen many circuits which allow you to turn on an LED when a magnet is placed close to a Hall effect sensor. But I need a circuit that will turn off the LED when the magnet is close to the sensor. I cannot use a latch since the magnet polarity cannot not be changed. I was thinking about using a switching transistor with the sensor and LED but I am not usre how to configure this correctly. Any suggestions?
I am using an OH090U Hall Effect sensor.