I've come into possession of a small hall sensor, mounted inside a pump. A little magnet inside the gearbox allow the control board to detect pumping rate, but suddenly the pump stopped operating complained a motor problem.
I feel this device is faulty, so I removed it. It consist of a small printed board with a SOT32 device marked "13E". Wires 1-3 leading out the board are shorted via a small cap and connected to two different pins of the device. The second wire directly connect to device pin 3.
Pinout is consistent with either Allegro A1213 or A3213, and so the first two digits on the package. But ony A3213 got an "E" version so...
Problem is that somewhere in the pump manual i found mention of a "reed sensor", and listed electrical caracteristics reported 24V operations with 20 mA output current.
So this would point toward A1213, wich does'nt come with "13E" markings, and would need a second magnet too, being a latching type switch.
And guess what, the rotating part wich host the magnet inside the gearbox actually has two exactly fit hole, on opposite sides of wheel, but only one got a magnet in it!!! Has a second, reverse polarity, magnet fell off [and triggered the initial fault btw] ?. Or I'm being mislead by the manual?
Somebody can suggest an alternative identification for the component?