Hall Effect Sensor Circuit
This circuit is designed for use as a 3D printer End Stop, but can be used for many other applications such as: CNC, proximity switch, RPM sensor
(additional circuitry needed), hidden switch activated with a magnet etc. This type of sensor allows a more repeatable setup and since it is a non-contact device
does not wear out as does a mechanical switch.
Specs:
-Voltage Supply specs: 4.5V min-25V max
-Output can switch at 250khz which equates to a theoretical 15 million RPM of rotational speed (1hz= 60rpm)
-3 wire interface +V, Gnd, Output on a standard 3 pin 2.54mm (.1") header connector
-Dual Red/Green LED indicator aids in setup/calibration of end use application
-Jumper option to prevent LED from lighting if desired once the board has been adjusted and is in use
-Overall size of the board is 13mm X 22mm (.51" X .87")
-Supplied with one rare earth magnet (1/4"diameter X 1/16" thick) per circuit ordered
-Mounting holes are located to match with the standard RepRap End Stop mount and will accept a 3mm or smaller screw. The center to center
distance between the holes is 10mm (.394") and the hole diameter is 3.18mm (.125").
Detailed Operation Instructions:
-Bicolor LED indicator Green/Red: Green=Supply Voltage on output wire, Red=Gnd on output wire 20ma sink capability. The output is pulled up
to the supply voltage when there is no magnetic field present at the sensor and is indicated with the Green LED on. The output goes to ground
and can sink up to 20ma of current when there is a magnetic field present at the sensor and is indicated with the Red LED on.
-With the supplied magnet the operate distance is about 3/8" and the release distance is about 3/4" (once the circuit has switched with the
magnet in proximity it must be moved away this far to reset) or can be used with any magnet (stronger magnet activates circuit from a greater
distance, weaker magnet must be closer to sensor to operate circuit).
Important Note: One side (front or back face, not edges) of the hall effect sensor device will be triggered by one of the poles of a magnet and
the opposite side (front or back face, not edges) of the sensor will be triggered by the opposite pole of the magnet. The user should mount the
circuit board and position the sensor, then test which pole of magnet should be mounted towards the sensor before final placement of the
magnet.