Bring to your attention a curious device invented by me - an indicator of polarity of the magnet.
That inspired me to create it: the building of my , as well as the desire to practice to get acquainted with modern operational amplifiers (current does not require a bipolar power supply, which is very convenient).
Works this devays this: when power is on (battery 6F22 9 V) green light. If near the Hall probe is not a magnet, then the blue and red LEDs do not light.
When approaching the north pole of a magnet to the sensor lights up blue LED
and southern red.
If you rotate the rotor brushless motor near the sensor, then the blue and red lights alternate, corresponding to passing by the poles of a magnet.
The device is built from dual OC LM358 as a comparator, the stabilizer 78L05, three LEDs (red, blue and green), a few resistors and 1 k
The device can be applied to other similar Hall sensor, for example, a popular and inexpensive VHE-101B. But it is necessary to comply with the pins of the sensor is connected correctly - in the absence of an external magnetic field the voltage across the diagonal of the bridge should be equal to zero.
Variable resistor, you must configure the circuit so that the voltage between its average output and negative power wires was less than 2.5 V (less than it is, the weaker sensitivity make). If voltage is not configured to exceed this threshold, then both LEDs are lit - and the blue and red.
The PCB is made by drawing
Метки: comparator, Hall sensor, LM358, magnet, magnetic field indicator, magnetic pole, magnetic pole indicator, operational amplifier, polarity, pole