The **HRS-5D-R** is a specific model of a **Miniature PCB Power Relay** commonly manufactured by brands like **HKE** (Zhejiang HKE Relay). It is widely used in home appliances, office equipment, and industrial automation due to its compact size and high switching capacity. ### 1. Part Number Breakdown Understanding the nomenclature helps identify the specific characteristics of this electronic component: | Code Segment | Description | Specific Value | | :--- | :--- | :--- | | **HRS** | Series Name | Miniature Power Relay | | **5** | Coil Voltage | 5V DC | | **D** | Coil Sensitivity | Standard DC Coil (approx. 0.36W - 0.45W) | | **R** | Contact Arrangement | Form C (SPDT - Single Pole Double Throw) | --- ### 2. Technical Specifications The following table highlights the core electrical and physical parameters of the HRS-5D-R: | Parameter | Specification | | :--- | :--- | | **Contact Form** | 1C (SPDT) | | **Contact Material** | Silver Alloy | | **Max Switching Voltage** | 250VAC / 30VDC | | **Max Switching Current** | 3A to 10A (Depending on specific sub-version/load) | | **Nominal Coil Voltage** | 5V DC | | **Coil Resistance** | ~70Ω (at 5V) | | **Dielectric Strength** | 1000VAC (between open contacts) | | **Mounting Type** | Through-hole PCB | --- ### 3. Pin Configuration and Operation The HRS-5D-R typically features 5 pins. Below is the internal logic for a **Form C (SPDT)** relay: 1. **Coil Pins (2 Pins):** When 5V DC is applied across these pins, the electromagnetic coil generates a field that pulls the armature. 2. **Common (COM):** The movable contact connected to the circuit you wish to switch. 3. **Normally Closed (NC):** The pin connected to COM when the relay is **unpowered**. 4. **Normally Open (NO):** The pin that connects to COM only when 5V is **applied** to the coil. --- ### 4. Application Circuit Example When driving this relay with a microcontroller (like an Arduino or ESP32), you cannot power it directly from an I/O pin because the coil draws more current than the pin can provide. A transistor driver circuit is required: ```python # Conceptual Wiring Diagram [MCU Pin] -> [1k Resistor] -> [Base of NPN Transistor (e.g., PN2222)] [Emitter] -> [GND] [Collector] -> [Relay Coil Pin 1] [5V Supply] -> [Relay Coil Pin 2] # IMPORTANT: Place a Flyback Diode (e.g., 1N4148) across the coil pins # to protect against voltage spikes. ``` ---