Here is a motor speed sensor module, the major goal is to check the rate of an electric motor. The module can be used in association with a microcontroller for motor speed detection, pulse count, position limit, etc. In principle, any rate meter simply measures the rate at which some event occurs. Usually this is done by counting the events for a given period of time (integration interval) and then simply dividing the number of events by the time to get the rate.
Groove width 10 mm.
the working voltage of 3.3 V to 5 V
output form: digital switch output (0 and 1)
PCB size: 2.3 cmx2cm
use the LM393 wide voltage comparator