Sensor Speed Module LM393 Chip And The 5mm Slot

Description

Unlike the obstacle avoidance sensor that relies on reflection, this module uses a photo-interrupter (the U-shaped black component). Inside the “U” are an IR transmitter and a receiver facing each other.

When the slot is empty, the receiver sees the IR light and stays in one state. When an opaque object—such as the tooth of a gear or a specialized encoder disk—passes through the slot, it blocks the beam. The onboard LM393 comparator chip translates these light-breaks into a clean digital pulse signal. By counting how many times the beam is broken per second, a microcontroller can calculate the exact speed (RPM) of a motor.

Key Features

• Dual Output Options: Features both Digital (DO) and Analog (AO) pins. The digital output provides clear pulses, while the analog output can be used for more nuanced detection of the blocking object’s density.
• Wide Slot Width: Typically features a 5mm to 10mm gap, allowing it to accommodate various encoder disks or mechanical parts.
• Signal Stability: The LM393 chip ensures a stable, “bounceless” signal, which is critical for high-speed counting.
• Mounting Hole: Includes a pre-drilled hole for easy mounting onto motor brackets or chassis.

Usage Tips for Your Projects

• The Encoder Disk: For speed measurement, you will need a disk with “teeth” or slots. The more slots the disk has, the higher the resolution and accuracy of your speed reading.
• Logic State: Usually, the digital output (DO) is LOW when the beam is clear and goes HIGH when the beam is blocked.
• Interference: Because it uses infrared light, very bright direct sunlight can sometimes interfere with the receiver. Mounting it inside a small enclosure or away from direct light is best for high-precision kits.