{"product_id":"moc-7811-encoder-sensor-slotted-opto-isolator-compoden","title":"MOC-7811 Encoder Sensor - Slotted Opto Isolator | Compoden","description":"\u003ch1\u003eMOC-7811 Slotted Opto Isolator – Encoder \u0026amp; Speed Sensor\u003c\/h1\u003e\n\n\u003cp\u003eThe MOC-7811 is an infrared slotted optical switch consisting of an IR LED and a phototransistor in a compact 4-pin housing. It detects opaque objects passing through its 3mm slot, making it ideal for RPM measurement, position encoding, and limit detection in robotics, motor control, and industrial automation.\u003c\/p\u003e\n\n\u003ch2\u003eKey Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSlot Width\u003c\/td\u003e\n\u003ctd\u003e3 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eIR LED Peak Wavelength\u003c\/td\u003e\n\u003ctd\u003e940 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePhototransistor V\u003csub\u003eCEO\u003c\/sub\u003e Max\u003c\/td\u003e\n\u003ctd\u003e30 V\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCollector Current (Max)\u003c\/td\u003e\n\u003ctd\u003e20 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCTR (Typical at I\u003csub\u003eF\u003c\/sub\u003e=20mA)\u003c\/td\u003e\n\u003ctd\u003e20%\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e-25°C to +85°C\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eWhat You Can Build With This\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eMotor RPM counter using a slotted wheel\u003c\/li\u003e\n  \u003cli\u003eLinear position encoder for 3D printers or CNC machines\u003c\/li\u003e\n  \u003cli\u003eLimit switch for robotic arm end‑stops\u003c\/li\u003e\n  \u003cli\u003eObject‑counting conveyor belt system\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eCompatibility\u003c\/h2\u003e\n\u003cp\u003eWorks with any 5V or 3.3V microcontroller including Arduino Uno, NodeMCU, and Raspberry Pi Pico. The LED requires a current‑limiting resistor (typically 220–330Ω at 5V). The phototransistor output can be read directly via a digital input with an external pull‑up resistor (10kΩ recommended).\u003c\/p\u003e\n\n\u003ch2\u003eWiring Notes\u003c\/h2\u003e\n\u003cp\u003eConnect the LED anode to VCC via a resistor and cathode to GND. The phototransistor collector goes to VCC (with pull‑up) and emitter to GND. Ensure the emitter load does not exceed 20mA. For clean signals, add a 100nF decoupling capacitor near the sensor.\u003c\/p\u003e\n\n\u003ch2\u003eWhy Buy from Compoden\u003c\/h2\u003e\n\u003cp\u003eEvery component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.\u003c\/p\u003e\n\n\u003cdetails\u003e\u003csummary\u003eIs this compatible with Arduino?\u003c\/summary\u003e\u003cp\u003eYes, connect the phototransistor output to any digital pin with a 10kΩ pull‑up resistor to VCC. Use digitalRead() to sense the slot state.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eCan I use it for a wheel encoder at high RPM?\u003c\/summary\u003e\u003cp\u003eThe MOC-7811 can handle pulse rates up to a few kHz, which is adequate for most low‑ to medium‑speed applications. For high RPM, ensure the slot wheel segmentation matches the sensor's response time.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eDoes it require an external crystal or oscillator?\u003c\/summary\u003e\u003cp\u003eNo, it is a simple optical switch. You only need power for the LED and a pull‑up for the output.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdiv class=\"compoden-handoff\" style=\"margin-top:24px;padding:16px;background:#f0f4ff;border-left:4px solid #2B4D8F;border-radius:4px;\"\u003e\n  \u003cp style=\"margin:0 0 6px 0;font-weight:600;color:#1A3560;\"\u003e📦 Free Setup Handoff Document Included\u003c\/p\u003e\n  \u003cp style=\"margin:0;font-size:0.95em;color:#333;\"\u003eEvery Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.\u003c\/p\u003e\n\u003c\/div\u003e\n","brand":"Compoden","offers":[{"title":"Default Title","offer_id":53445023924589,"sku":"CDN-0759","price":25.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0999\/3997\/5533\/files\/download_a2a1531b-94ce-4828-ba3b-17c736804313.jpg?v=1781592692","url":"https:\/\/compoden.com\/products\/moc-7811-encoder-sensor-slotted-opto-isolator-compoden","provider":"Compoden","version":"1.0","type":"link"}