The **LHZ-22H-R** is a specific model of a **magnetic proximity sensor** (often referred to as a reed switch or magnetic switch), typically used in pneumatic systems to detect the position of a piston inside an air cylinder. --- ### 1. Technical Specifications The following table summarizes the key electronic characteristics of the LHZ-22H-R: | Feature | Specification | | :--- | :--- | | **Switching Logic** | SPST (Single Pole Single Throw), Normally Open | | **Sensor Type** | Reed Switch | | **Operating Voltage** | 5V - 240V AC/DC | | **Switching Current** | 100mA max | | **Contact Rating** | 10W max | | **Voltage Drop** | 2.5V max @ 100mA | | **Indicator Lamp** | Red LED (Lights up when triggered) | | **Cable Length** | Usually 2 Meters (Standard PVC) | --- ### 2. Core Electronic Components The device consists of three primary internal parts: 1. **Reed Switch:** A small glass envelope containing two ferromagnetic flexible metal contacts. When a magnet (attached to the cylinder piston) comes near, the magnetic field pulls the contacts together, closing the circuit. 2. **LED Indicator:** A light-emitting diode wired in series with a current-limiting resistor. This provides visual feedback to technicians, showing that the sensor has successfully detected the magnet. 3. **Internal Protection:** Most models include a basic varistor or diode circuit to protect the reed contacts against small voltage spikes, although external protection is recommended for highly inductive loads. --- ### 3. Wiring Configuration The LHZ-22H-R is a **2-wire** sensor. Because it operates on a wide range of voltages, it is highly versatile but must be wired in series with a load. * **Brown Wire:** Connects to the Positive (+) side of the power source. * **Blue Wire:** Connects to the Load (PLC Input, Relay Coil, etc.), which then connects to the Negative (-) or Common side of the power source. > **Warning:** Never connect the Brown and Blue wires directly across a power supply without a load; this will cause an immediate short circuit and destroy the internal reed switch. --- ### 4. Comparison: Reed vs. Solid State The "H" in the model name usually denotes the Reed type, whereas electronic (Solid State/NPN/PNP) sensors operate differently: | Feature | LHZ-22H-R (Reed) | Solid State (Electronic) | | :--- | :--- | :--- | | **Durability** | Mechanical (wear over time) | No moving parts (Longer life) | | **Voltage Range** | Very Wide (AC/DC) | Limited (usually 10-30V DC) | | **Response Time** | Slower (~0.5ms) | Very Fast (~0.1ms) | | **Leakage Current** | Zero | Small amount present |