How The Sensor Works

The photoelectric sensor is a small electronic device, a key component for photoelectric conversion in various photoelectric detection systems. It mainly uses various properties of light to detect the presence or absence of objects and changes in surface conditions. It is mainly controlled by converting changes in light intensity into changes in electrical signals. Generally, it is composed of three parts: transmitter, receiver and detection circuit. The transmitter is aimed at the target to emit a light beam. The emitted light beam generally comes from a semiconductor light source, a light emitting diode, a laser diode, and an infrared emitting diode. The beam is emitted uninterrupted, or the pulse width is changed. The receiver is composed of photodiode, phototransistor and photocell. In front of the receiver, optical components such as lenses and apertures are installed. Behind it is the detection circuit, which can filter out the valid signal and apply the signal.

According to different detection methods, photoelectric sensors can be divided into several different types. Next, we will follow the photoelectric sensor manufacturers to understand.

1. Diffuse reflection type photoelectric switch

Under normal circumstances, the light receiver emitted by the light emitter cannot be found. When the detection object passes through, it blocks the light and reflects the light part back. The receiver receives the signal and outputs a switching signal.

2. Optical fiber photoelectric switch

The optical fiber photoelectric switch uses plastic or glass optical fiber sensors to guide the light, so that the detected object is not in the close area. Generally, optical fiber sensors are classified into through-beam type and diffuse reflection type.

3. Reflective plate type photoelectric switch

Under normal circumstances, the light emitted by the light emitter is reflected back by the reflector and received by the light receiver; once the light path is blocked by the detection object and the light receiver does not receive the light, the photoelectric switch acts and outputs a switch control signal.

4. Opposite type photoelectric sensor

It is composed of a transmitter and a receiver, which are separated from each other in structure. When the light beam is interrupted, a switching signal changes. The typical way is that the photoelectric switches on the same axis can be separated from each other by up to 50 meters.

5. Slot photoelectric sensor

The grooved photoelectric switch is safe and reliable, suitable for detecting high-speed changes and distinguishing between transparent and translucent objects.