The **B136-R** typically refers to a specific component model often associated with **NPN Silicon Epitaxial Planar Transistors** (specifically the 2SB136R, though often abbreviated in catalogs) or, more commonly in modern contexts, a specific **Passive Video Balun Receiver**. Below is the technical breakdown of the electronic characteristics for both common interpretations of this part number. --- ## 1. B136-R: Passive Video Balun (CCTV Component) In most modern electronics retail contexts, the B136-R is a remote-unit passive video balun used to transmit video signals over Unshielded Twisted Pair (UTP) cables (like Cat5e/Cat6). ### Technical Specifications | Feature | Specification | | :--- | :--- | | **Signal Type** | Composite Video (CCTV) | | **Transmission Distance** | Up to 330m (Color), 600m (B&W) | | **Impedance (BNC)** | 75 Ohms | | **Impedance (UTP)** | 100 Ohms | | **Frequency Response** | DC to 8 MHz | | **CMRR** | 60 dB | ### Key Electronic Internal Parts * **Magnetic Toroid Core:** A small transformer core that matches the impedance between the unbalanced BNC (75Ω) and the balanced UTP (100Ω). * **TVS Diode:** Often included for surge protection against voltage spikes. * **Filter Capacitors:** Used to reduce noise and interference from electromagnetic sources. --- ## 2. 2SB136-R: Power Transistor If you are referring to the semiconductor component (often marked simply as B136 on the casing with an 'R' gain suffix), it is a PNP power transistor used for switching and amplification. ### Absolute Maximum Ratings (at Ta = 25°C) | Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Collector-Base Voltage | $V_{CBO}$ | -60 | V | | Collector-Emitter Voltage | $V_{CEO}$ | -60 | V | | Emitter-Base Voltage | $V_{EBO}$ | -7 | V | | Collector Current | $I_C$ | -3 | A | | Power Dissipation | $P_C$ | 1.5 - 20 (with heatsink) | W | ### The "R" Suffix Meaning In semiconductor coding, the **R** suffix typically denotes the **hFE (Current Gain)** classification. For this series: * **R Rank:** Generally represents a gain range of **40 to 80**. * **O Rank:** 70 to 140. * **Y Rank:** 120 to 240. --- ## Comparison Summary If you are repairing a device, use the guide below to identify which B136-R you have: 1. **If it has a BNC connector and green screw terminals:** It is the **Video Balun**. It is used for security camera wiring. 2. **If it is a black plastic piece with 3 metal legs (TO-220 package):** It is the **PNP Transistor**. It is used in power supply circuits or motor drivers.