Anonymous
Mar 21, 2026
Rating: 5/5
Reliable for production testing
We bought ten of these for our assembly line motor testing station. They have been running 8 hours a day for a month with zero failures.
Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Operating Voltage | 3.3V - 5V DC |
| Output Type | Digital Switching (TTL) |
| Sensor Type | Slotted Optical Interrupter |
| Slot Width | 5mm |
| Response Time | < 10 microseconds |
| LED Indicator | Yes (Power and Signal) |
| Mounting Hole Diameter | 3mm |
| PCB Dimensions | 32mm x 14mm |
| Connector Type | 3-Pin Header (GND, VCC, OUT) |
| Application | Motor Speed Testing, RPM Counting, Object Detection |
Anonymous
Mar 21, 2026
Rating: 5/5
Reliable for production testing
We bought ten of these for our assembly line motor testing station. They have been running 8 hours a day for a month with zero failures.
Anonymous
Mar 21, 2026
Rating: 5/5
Perfect for DIY Tachometers
This module works flawlessly with my Arduino project. The signal is clean and stable even at high motor speeds. Very easy to integrate.
Anonymous
Mar 17, 2026
Rating: 4/5
Solid component
The build quality is decent for the price. The LEDs are bright enough to see status in daylight. Would recommend adding a pull-up resistor if your microcontroller doesn't have one enabled internally.
Anonymous
Mar 16, 2026
Rating: 5/5
Great for beginners
I was worried about wiring this up, but the labels on the PCB are clear. It lit up immediately and started detecting my coded wheel without issues.
Anonymous
Mar 15, 2026
Rating: 5/5
Fast response time
Used this to monitor propeller speed on a test bench. The response time is incredibly fast, capturing every pulse accurately up to 10k RPM.
Anonymous
Mar 11, 2026
Rating: 4/5
Good value, minor alignment needed
Works well for counting rotations. You need to make sure the disc passes exactly through the center of the slot, but once aligned, it is very reliable.
Q: Can I use this to count water flow if I attach a spinner?
A: Yes, provided you attach a non-transparent flag or coded disk to the spinner that passes through the slot. Ensure the mechanism is sealed so water does not reach the electronic components.
Q: Does this module output analog or digital signals?
A: This is a digital switching module. It outputs a LOW signal when the slot is blocked and a HIGH signal when the slot is clear (or vice versa depending on logic configuration).
Q: What is the maximum width of the object that can pass through the slot?
A: The slotted optocoupler has a gap width of approximately 5mm. Any opaque object thinner than 5mm can interrupt the beam effectively.
Q: Is there a way to adjust the sensitivity of the sensor?
A: No, this specific model does not have a potentiometer for sensitivity adjustment. It is calibrated at the factory for standard object detection tasks.
Q: Can this sensor work with a 3.3V microcontroller like ESP32?
A: Yes, this module supports a wide voltage range from 3.3V to 5V, making it fully compatible with ESP32, ESP8266, and standard 5V Arduinos.