The **JS0404AP4-R** is a specific type of **DIP (Dual In-line Package) Switch**, commonly used in electronics to manually configure settings on a printed circuit board (PCB). It is a "piano-style" switch, meaning the actuators are side-actuated, resembling piano keys. ### 1. Technical Specifications Below are the primary technical characteristics of the JS0404AP4-R: | Feature | Specification | | :--- | :--- | | **Switch Type** | DIP / Piano Style | | **Number of Positions** | 4 Positions (4 individual switches) | | **Actuator Style** | Side Actuated (Piano) | | **Pitch (Spacing)** | 2.54 mm (0.100") | | **Contact Rating** | 25mA @ 24VDC (Switching) / 100mA @ 50VDC (Non-switching) | | **Mounting Type** | Through-Hole (THT) | | **Contact Material** | Gold Plated (for high reliability) | --- ### 2. Physical Design and Function The "AP4" in the part number generally refers to the number of poles and the physical orientation. * **Piano Actuation:** Unlike standard slide DIP switches that you toggle from the top, the piano style allows users to flip the switches from the edge of the board. This is ideal when boards are stacked or enclosed in a chassis where top access is restricted. * **Gold Contacts:** These switches typically use gold-over-nickel plating to prevent oxidation, ensuring a long shelf life and stable electrical connection even in humid environments. * **Sealing:** These often come with a top tape seal (indicated by the "-R" or similar suffixes in some series) to allow for wave soldering and aqueous cleaning without contaminating the internal contacts. --- ### 3. Common Applications The JS0404AP4-R is used in scenarios where hardware logic needs to be set permanently or semi-permanently: 1. **Address Setting:** Setting the unique ID for a device on a bus (e.g., RS-485 or DMX networks). 2. **Configuration:** Selecting baud rates, operating modes, or frequency bands on industrial equipment. 3. **Security:** Encoding remote control codes (common in older garage door openers). 4. **Prototyping:** Manually pulling microcontroller pins HIGH or LOW during the testing phase. --- ### 4. Typical Internal Circuit Each of the 4 switches acts as a simple **SPST (Single Pole Single Throw)** toggle. ```text ON (Closed) | [1] --/ -- [8] [2] --/ -- [7] [3] --/ -- [6] [4] --/ -- [5] ``` ---