The **2JS40-R** is a specific type of high-voltage silicon rectifier diode commonly used in television sets (specifically CRT monitors), voltage multipliers, and high-frequency power supplies. --- ### ## Technical Specifications Below are the primary electrical characteristics for the 2JS40-R rectifier: | Parameter | Value | | :--- | :--- | | **Repetitive Peak Reverse Voltage ($V_{RRM}$)** | 40 kV (40,000 Volts) | | **Average Forward Current ($I_{F(AV)}$)** | 5.0 mA | | **Max Forward Voltage Drop ($V_F$)** | Approx. 50V - 100V | | **Reverse Recovery Time ($t_{rr}$)** | Fast Recovery (varies by manufacturer) | | **Operating Temperature** | -40°C to +120°C | --- ### ## Key Features 1. **High Voltage Rating:** Capable of handling up to 40kV, making it suitable for the "anode" voltage generation in vacuum tube and CRT technology. 2. **Compact Molded Design:** Usually features a cylindrical resin-molded body with axial leads to prevent arcing and corona discharge. 3. **Fast Recovery:** Designed to work with high-frequency flyback transformers. 4. **Reliability:** High thermal stability for long-term operation in enclosed high-voltage environments. --- ### ## Internal Construction Internally, a 2JS40-R is not a single diode junction. Because a single silicon junction can only withstand a few hundred to a thousand volts, the 2JS40-R consists of **multiple diode chips stacked in series** inside the molded casing. * **Total Voltage:** The sum of the breakdown voltages of all individual chips. * **Encapsulation:** High-insulation epoxy resin is used to prevent internal electrical breakdown between the junctions. --- ### ## Common Applications * **CRT Television Sets:** Used in the flyback transformer assembly to provide the high voltage required for the picture tube. * **Electrostatic Air Cleaners:** Used to generate the static charge needed to attract dust particles. * **X-Ray Power Supplies:** Small-scale portable X-ray equipment. * **Laser Power Supplies:** Ignition circuits for gas lasers. --- ### ## Safety and Handling > **Warning:** When working with the 2JS40-R, you are dealing with lethal voltages. > 1. Ensure the circuit is fully discharged before touching the component. > 2. Maintain "creepage distance" (physical space) between the diode leads and other conductive parts to prevent sparking through the air.