The **47DAC-112-R** is a specific model of a **Miniature Power Relay**, commonly manufactured by brands like **CIT Relay & Switch**. It is designed to switch high-current loads while maintaining a small physical footprint on a Printed Circuit Board (PCB). --- ### 1. Technical Specifications Breakdown The model number identifies the specific characteristics of the component: | Feature | Specification | Description | |:---|:---|:---| | **Contact Form** | SPST (1 Form A) | Single Pole, Single Throw (Normally Open). | | **Coil Voltage** | 12V DC | The voltage required to energize the electromagnet. | | **Contact Rating** | 5A to 10A | Capable of handling significant current at 125VAC/250VAC. | | **Termination** | PCB Terminals | Designed for through-hole mounting on circuit boards. | | **Sealing** | Sealed | Protected against soldering flux and cleaning processes. | --- ### 2. Internal Components A relay like the 47DAC-112-R consists of several critical electronic and mechanical parts: * **Electromagnetic Coil:** A coil of fine copper wire that creates a magnetic field when 12V DC is applied. * **Armature:** A moving lever that is pulled by the magnetic field of the coil. * **Contacts:** Usually made of Silver Tin Oxide ($AgSnO_2$) or Silver Nickel ($AgNi$) to resist "arcing" and welding when switching power. * **Spring Mechanism:** Returns the armature to its original position once power is removed from the coil. --- ### 3. Connection Diagram (Standard Layout) Most relays in this series follow a standard pinout configuration: ```text [ Coil ]-------( )-------[ Coil ] Pin 1 Pin 2 [ COM ]-----------------[ NO ] Pin 3 Pin 4 ``` *Note: In a 1 Form A configuration, there is no NC (Normally Closed) pin.* --- ### 4. Common Applications The 47DAC-112-R is typically found in: 1. **Home Appliances:** Controlling heating elements or motors in coffee makers and toasters. 2. **HVAC Systems:** Switching fans or small compressors. 3. **Industrial Controls:** Interfacing between low-power microcontrollers (like Arduino/ESP32) and high-voltage AC loads. 4. **Security Systems:** Actuating sirens or electronic locks.