RPM Phase Sensor connected to eFlightWatt wattmeter/data logger permits direct measurement of a brushless motor RPM. Our unique design incorporates voltage protection and allows you to use this sensor with any number of cells (the maximum voltage this Phase Sensor can work with is higher than 10S limitation of eFlightWatt).

The size of the circuit board is 13mm x 10mm (0.5" x 0.4") and its weight, most of which is the weight of the wires, is about 4g (0.14oz).