The **BZ-R-A2** is a high-precision, premium-grade **Standard Basic Micro Switch** manufactured by Honeywell (Sensing and Productivity Solutions). It belongs to the legendary **BZ Series**, which is known for its long service life and high repeatability. --- ### 1. Technical Specifications The following table summarizes the core electronic and mechanical parameters of the BZ-R-A2: | Parameter | Specification | | :--- | :--- | | **Switch Type** | SPDT (Single Pole Double Throw) | | **Actuator Type** | Pin Plunger | | **Current Rating (AC)** | 15 A | | **Voltage Rating (AC)** | 125 V / 250 V / 480 V | | **Termination Style** | Screw Terminals | | **Operating Force** | 2.5 N to 3.61 N (9 oz to 13 oz) | | **Contact Material** | Silver | | **Housing Material** | General Purpose Phenolic | --- ### 2. Key Internal Components The BZ-R-A2 is engineered with specific electronic and structural parts to ensure reliability: * **Silver Contacts:** The internal contact points are made of silver. This provides low electrical resistance and high conductivity, making it suitable for standard power-level switching. * **Snap-Action Mechanism:** It utilizes a "beryllium copper" spring mechanism. This ensures that the transition between NO (Normally Open) and NC (Normally Closed) is instantaneous, regardless of the speed of the external actuator. * **Phenolic Housing:** The outer casing is made of a thermosetting plastic (Phenolic). This material provides high dielectric strength and heat resistance, protecting the internal electronics from short circuits. * **Screw Terminals:** It features #6-32 terminal screws with cup washers, allowing for secure wiring without the need for soldering. --- ### 3. Circuit Configuration As an **SPDT** switch, the BZ-R-A2 has three distinct connection points: ```mermaid graph LR A[COM - Common] --- B[NC - Normally Closed] A --- C[NO - Normally Open] ``` * **At Rest:** The circuit is closed between the Common (COM) and the NC terminal. * **When Actuated:** The plunger is depressed, snapping the internal contact to the NO terminal and breaking the NC connection. --- ### 4. Applications Due to its robust electronic design, the BZ-R-A2 is commonly used in: 1. **Industrial Limits:** Sensing the position of machine parts. 2. **Safety Interlocks:** Ensuring doors or panels are closed before power is applied. 3. **Timing Devices:** Integrated into mechanical timers to trigger electrical cycles.