In the realm of industrial automation and electronic control, achieving reliable and precise object detection is paramount. Among the various sensing technologies available, the slot type photoelectric switch stands out for its accuracy and versatility. Today, we focus on a specific and widely utilized component: the slot type photoelectric switch sensor models EE-SX670 and EE-SX671. These sensors represent a critical solution for applications requiring non-contact detection within a confined space.
A slot type photoelectric sensor, often called a through-beam sensor in a compact form, consists of an integrated transmitter and receiver facing each other across a small gap or "slot." The EE-SX670 and EE-SX671 models embody this design perfectly. An infrared light-emitting diode (LED) on one side continuously emits a beam of light, which is received by a phototransistor on the opposite side. The core operating principle is straightforward: when an object passes through the slot, it interrupts this light beam. The sensor detects this interruption and triggers a change in its output signal. This simple yet effective mechanism allows for the detection of very small objects, such as paper edges, tiny gears, or encoder disk slots, with high repeatability.
The EE-SX670 and EE-SX671 sensors, while similar, offer distinct output configurations to suit different circuit requirements. The EE-SX670 typically features a phototransistor output. This type of output allows the sensor to be easily integrated with a pull-up resistor to create a simple digital signal—high when the beam is uninterrupted and low when it is blocked. It offers flexibility for designers to condition the signal as needed for microcontrollers or logic circuits. On the other hand, the EE-SX671 often incorporates a built-in amplifier and provides a digital output, such as a transistor output (NPN or PNP). This "amplifier-built-in" design simplifies the interface, as the output is already a clean, switched signal compatible with programmable logic controllers (PLCs) and other industrial control systems, requiring minimal external components.
These sensors are characterized by their compact size, which allows for installation in tight spaces where other sensors might not fit. The narrow detection slot enables high-precision positioning and the sensing of minute objects. They are commonly employed in a vast array of applications. In office automation, they are indispensable in printers and copiers for detecting paper presence, paper jams, and toner cartridge positioning. Within industrial machinery, they play a crucial role in counting products on a conveyor line, detecting the position of a robotic arm, verifying the presence of components in assembly machines, or reading slots on a rotary encoder to monitor speed and position. Their reliability makes them suitable for environments where mechanical limit switches might wear out or fail.
When integrating the EE-SX670 or EE-SX671 into a system, several practical considerations are essential. First, electrical compatibility is key. Ensure the operating voltage (typically 5V DC for many models) and output type match your control circuitry. Second, environmental factors matter. While these sensors are robust, excessive ambient light, dust, or oil mist can interfere with the infrared beam. Many models, including these, are designed to resist such interference, but it's prudent to consider the operating environment. Mounting the sensor securely to prevent vibration or misalignment is critical for consistent performance. Finally, for the EE-SX670, selecting the correct value for the external pull-up resistor is necessary to achieve the desired output current and voltage levels.
In summary, the slot type photoelectric switch sensors EE-SX670 and EE-SX671 are fundamental components for precise, non-contact detection. Their simple through-beam principle, packaged in a convenient slot format, provides a reliable solution for detecting the presence, absence, or position of objects. The choice between the basic phototransistor output of the EE-SX670 and the amplified, ready-to-use output of the EE-SX671 allows engineers to select the optimal interface for their specific application, balancing design simplicity with immediate system integration. By understanding their operation, specifications, and ideal use cases, designers can effectively leverage these sensors to enhance the accuracy and reliability of automated systems across numerous industries.
