LM393 Infrared Optocoupler Speed Sensor Module

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.

Basically, the microcontroller-compatible motor speed sensor module described is a simple device that yields processed pulse trains when the visual path of its optical sensor is physically interrupted by some sort of slotted wheel or similar mechanism (an optical sensor commonly consists of a light emitting diode that provides the illumination, and a phototransistor that senses the presence or absence of that illumination). The transmissive optical sensor used here consists of an infrared light emitting diode and a phototransistor. This both prevents interference from stray external light sources and by having the two components matched for a specific frequency of radiation, they are even more immune to undesired interference.