The 13001 6D is a high-voltage NPN bipolar junction transistor (BJT) mainly designed for fast switching applications. It is commonly found in power supply circuits such as LED bulbs, CFL lamps, adapters, and small SMPS (Switched Mode Power Supplies).
This transistor is part of the MJE13001 series, built to handle high collector-emitter voltage while switching at high speed. It is not meant for audio amplification or low-voltage signal processing, but rather for power switching in AC-DC conversion circuits.
 
Key Characteristics
Type: NPN BJT
High Voltage Rating: Up to 400V collector-emitter
Moderate Current Handling: Around 0.2A–0.5A
Fast Switching Capability
Low to Medium Gain (hFE)
 
Physical Package
It is usually available in:
TO-92 package (small plastic body, common in LED drivers)
Sometimes TO-126 package (larger body for better heat handling)
 
Main Purpose
The 13001 6D is specially designed for:
High-voltage switching
Flyback converter circuits
Electronic ballast circuits
Low-cost power supply designs
 
Important Note
Because it is a high-voltage transistor, it is mostly used in circuits connected to mains electricity (110V/220V AC). Proper safety precautions must be taken when handling such circuits.