The term **28-Z-R** typically refers to a specific configuration of a **rotary switch** or a specific high-frequency **RF attenuator/component** depending on the manufacturer. However, in the context of general electronic components, it most frequently identifies with the **NKK Switches** or similar rotary switch series specifications. Below is a breakdown of the technical aspects associated with components carrying this nomenclature. --- ### 1. General Specifications If referring to the common **28-Z-R rotary switch series**, the parts are characterized by their sub-miniature size and PCB mounting capabilities. | Feature | Description | | :--- | :--- | | **Component Type** | Rotary Switch / Selector | | **Mounting Type** | Through-hole (PCB) or Right Angle | | **Position Count** | Usually 2 to 8 positions (depending on the '28' prefix) | | **Contact Material** | Gold over Brass or Silver (R denotes RoHS compliance/Right angle) | | **Actuator Style** | Screwdriver slot or Knob-operated | --- ### 2. Breakdown of the Part Number Electronic part numbers are alphanumeric codes where each segment defines a physical or electrical property. ### `28` (Series/Size) Indicates the physical size and the base series of the component. In rotary switches, this often dictates the diameter of the switch body (e.g., 10mm or 12mm). ### `Z` (Contact/Terminal Material) In the electronic industry standard, **Z** often signifies: * **Terminal Logic:** Epoxy sealed terminals to prevent flux contamination during soldering. * **Contact Type:** Often refers to specific metal alloys used for low-voltage signal integrity. ### `R` (Orientation/Compliance) The suffix **R** is most critical and usually stands for one of two things: 1. **Right Angle:** The component is designed to be mounted at a 90-degree angle to the PCB. 2. **RoHS Compliant:** Indicates the part is manufactured without hazardous substances (Lead-free). --- ### 3. Key Electrical Characteristics These parts are generally used in low-power signal switching rather than high-power applications. * **Current Rating:** Typically 100mA @ 50V DC. * **Insulation Resistance:** 1,000 Megohms minimum. * **Dielectric Strength:** 500V AC for one minute. * **Mechanical Life:** 10,000 to 30,000 cycles. --- ### 4. Common Applications * **Industrial Controls:** Setting modes on a control board. * **Telecommunications:** Channel selection in radio equipment. * **Test Equipment:** Adjusting sensitivity or range scales on handheld meters. * **Medical Devices:** Internal calibration settings that are not frequently changed by the end-user.