The **D369-R9** (often associated with the Cherry/ZF D3 series) is a subminiature snap-action microswitch. These components are widely used in industrial and automotive applications due to their high reliability and compact size. ### Technical Specifications The D369-R9 is characterized by its specific electrical ratings and physical actuator configuration. | Feature | Specification | | :--- | :--- | | **Switch Type** | Subminiature Snap-Action | | **Circuitry** | SPDT (Single Pole Double Throw) | | **Current Rating** | 100mA (Signal Grade) | | **Voltage Rating** | 30V DC / 125V AC | | **Terminal Type** | Solder Terminals / PCB Pins (depending on variant) | | **Actuator Type** | Simulated Roller Lever | | **Operating Force** | ~45g to 150g (variant dependent) | --- ### Key Electronic Components & Construction #### 1. Contact Material Unlike high-power versions (which use Silver Alloy), the "R9" signal-grade variant often utilizes **Gold-plated contacts**. * **Benefit:** Gold prevents oxidation, ensuring high contact reliability at very low currents (logic level switching). #### 2. The Snap-Action Mechanism The internal "omega" spring or leaf spring provides a snap-over motion. This ensures that the transition between the Normally Closed (NC) and Normally Open (NO) states happens at a constant speed, regardless of how fast the external lever is pressed. #### 3. Housing (Thermoset Plastic) The body is typically made from high-grade PET or PBT plastics. This provides: * **Dielectric Strength:** High resistance to electrical breakdown. * **Thermal Stability:** Maintains its shape and mechanical tolerances under heat. ### Application Use Cases * **Precision Sensing:** Used in medical devices to detect door closures or fluid levels. * **Automotive:** Seatbelt latch detection or door lock positioning. * **Consumer Electronics:** Limit switches in high-end computer peripherals or appliances. --- ### Wiring Diagram (Typical SPDT) ```text [ Common (1) ] / / <-- Spring Mechanism (2) NC * * NO (3) ``` ---