EEEkit 4 Digital Blue LED Tachometer, RPM Speed Meter Digital Motor with Hall Proximity Switch Sensor NPN for Conveyor Belts...

Every thing works great.

This unit is easy to hook the sensor up. And easy to solder together. The tougher part is figuring out the wiring scenario. I use Google translate to help me with looking at the back of the LED module. 1: + and brown wire of sensor 2: ground 3: blue sensor wire 4: n/a 5: black sensor wire 12-24 volt power supply battery or transformer. The magnet provided will work, try flipping around and spinning on a drill to first check the sensor to determine what is the right direction. The South Pole is what the sensor will detect correctly.

This unit is easy to hook the sensor up. And easy to solder together. The tougher part is figuring out the wiring scenario. I use Google translate to help me with looking at the back of the LED module. 1: + and brown wire of sensor 2: ground 3: blue sensor wire 4: n/a 5: black sensor wire 12-24 volt power supply battery or transformer. The magnet provided will work, try flipping around and spinning on a drill to first check the sensor to determine what is the right direction. The South Pole is what the sensor will detect correctly.

I'll let my photo provide most of the details, but I am very frustrated to have wasted several hours trying to figure out this evidently defective device. In the course of testing it, I modified the cable, so cannot return. I'll be buying a competing product that has better documentation. The symptoms: After wiring the device, following the given instructions, the display remained dark and never showed digits when the Hall sensor was exposed to a varying magnetic signal. The polarity of the power supply and basic wiring was confirmed by the Hall sensor glowing and flickering in response to magnet motion. I then read more of the comments and saw that the number on the sticker were flipped. I rewired the unit to conform with the working configuration displayed in the youtube video "HOW TO WIRE DIGITAL TACHOMETER" cited in a comment. That's the final wiring layout in my image. I also tried flipping the magnet over as per another review, to no effect (except slightly lessening the sensor LED flicker). The fact that the wiring diagram and labeling on the case is suspect (see other reviews) should have tipped me off that this was not worth the money and time. It's outrageous that this kind of unit comes with no wiring specifications except the ZeeBooth page! Give us a clue, please.

I'll let my photo provide most of the details, but I am very frustrated to have wasted several hours trying to figure out this evidently defective device. In the course of testing it, I modified the cable, so cannot return. I'll be buying a competing product that has better documentation. The symptoms: After wiring the device, following the given instructions, the display remained dark and never showed digits when the Hall sensor was exposed to a varying magnetic signal. The polarity of the power supply and basic wiring was confirmed by the Hall sensor glowing and flickering in response to magnet motion. I then read more of the comments and saw that the number on the sticker were flipped. I rewired the unit to conform with the working configuration displayed in the youtube video "HOW TO WIRE DIGITAL TACHOMETER" cited in a comment. That's the final wiring layout in my image. I also tried flipping the magnet over as per another review, to no effect (except slightly lessening the sensor LED flicker). The fact that the wiring diagram and labeling on the case is suspect (see other reviews) should have tipped me off that this was not worth the money and time. It's outrageous that this kind of unit comes with no wiring specifications except the ZeeBooth page! Give us a clue, please.