Power Transistor BU406 NPN, 8A TO-220

Power Transistor BU406 NPN, 8A TO-220

Transistors

Reference: TRBU406

Part.No: BU406

€1.40

In Stock

Immediate Dispatch

The BU406 is a high-voltage NPN power transistor in a TO-220 package, specifically designed for high-speed switching applications in deflection circuits and line output stages (LOPT) of CRT monitors and television receivers.

Add to cart

Subscribe To When In Stock

You have successfully subscribed to this product

Description
Product Details

BU406 High-Speed Power Transistor - LOPT Deflection & CRT Monitor Replacement

The BU406 is a high-voltage NPN power transistor engineered for demanding switching applications in deflection and line output stages. Its exceptionally short fall time and fast switching characteristics make it the industry standard for CRT monitor and television LOPT circuits, where crisp line rendering depends on precise timing and reliable high-voltage switching.

Functions & Applications

Exceptionally Fast Switching: Ultra-short fall time ensures crisp, clear line rendering on CRT displays.
High Voltage Rated: Designed to handle the high-voltage demands of deflection and LOPT circuits in legacy CRT equipment.
TO-220 Power Package: Robust through-hole design with mounting pad for efficient heatsinking via mica insulator and thermal paste.
Reliable LOPT Replacement: Direct replacement for original BU406 parts in CRT monitors and portable televisions from the 1980s–2000s era.

Technical Specifications

Parameter	Value / Specification
Transistor Type	BJT (Bipolar Junction Transistor)
Polarity / Channel	NPN
Package / Case	TO-220
Max Collector Current (Ic)	8A
Collector-Emitter Voltage (Vceo)	400V
Power Dissipation (Pd)	50W
Mounting Type	Through-Hole (THT) with Heatsink

Frequently Asked Questions

Q: Why does the BU406 fail immediately after replacement in my CRT monitor?
A: The BU406 rarely fails on its own; check for cold solder joints on the flyback transformer leads and verify that all associated high-voltage circuit components (especially output transformer and resonant tank) are intact. Always test under no-load conditions first.

Q: Do I need a heatsink when installing the BU406?
A: Yes, mandatory. The BU406 must be mounted to a heatsink via a mica insulator with thermal paste applied. Without proper cooling, the transistor will overheat and fail within minutes of operation.

Notes

Legacy CRT part. High-speed LOPT transistor prone to failure if circuit faults (especially output transformer or resonant tank defects) are not resolved before replacement. Always verify secondary circuit health.

Note: Price refers to one (1) piece. The component is shipped in bulk without individual packaging.

Transistor Type: BJT (Bipolar Junction Transistor)
Transistor Polarity / Channel: NPN
Transistor Case Style: TO-220

16 other products in the same category:

Transistor BC178 PNP 25 V 200 mA 300 mW TO-18

Transistors

Transistor BC178 PNP 25 V 200 mA 300 mW TO-18

Reference:

TRBC178

Το BC178 είναι ένα γενικής χρήσης PNP Bipolar Junction Transistor (BJT) σε μεταλλική θήκη TO-18. Κατάλληλο για ενίσχυση ασθενών σημάτων και switching χαμηλής ισχύος σε ηχητικά και γενικά κυκλώματα.

In Stock

Transistor BD169 NPN, 80V, 1.5A, 20W, TO126

Transistors

Power Transistor BD169 NPN, 1.5A TO-126

Reference:

TRBD169

The BD169 is an NPN power transistor in a TO-126 package, rated for 80V and 1.5A. Suited for driver stages, audio amplifiers and medium-power switching circuits.

Last items in stock

Transistor BC309 PNP, 20V, 100mA, 300mW, TO-92

Transistors

Transistor BC309 PNP, 100mA TO-92

Reference:

TRBC309

The BC309 is a PNP Bipolar Junction Transistor (BJT) in a TO-92 package, rated for 20V / 100mA / 300mW. Suited to small-signal amplification and low-power switching in general-purpose and educational circuits.

Last items in stock

Power Transistor AD155 PNP, TO-3

Transistors

Power Transistor AD155 PNP, TO-3

Reference:

TRAD155

The AD155 is a classic PNP Germanium Power Transistor in a TO-3 package. Designed for the output stages of vintage audio amplifiers and high-current switching applications where robust performance and direct heatsink mounting are essential.

In Stock

Power Transistor BD435 NPN, 8A TO-126

Transistors

Power Transistor BD435 NPN, 8A TO-126

Reference:

TRBD435

The BD435 is a medium-power NPN Bipolar Junction Transistor (BJT) in a TO-126 package. Built for reliable output-stage amplification and push-pull topologies in audio amplifiers, DC power supplies, and automotive electronics.

Last items in stock

Transistor JFET BF245 N-Channel

Transistors

Transistor JFET BF245 N-Channel

Reference:

TRBF245

The BF245 (often A, B, or C) is arguably the most famous N-Channel JFET in Europe. Plastic TO-92 package.

Last items in stock

Transistor BD236 PNP, 60V, 2A, 25W, TO-126

Transistors

Power Transistor BD236 PNP, 2A TO-126

Reference:

TRBD236

The BD236 is a PNP Bipolar Junction Transistor (BJT) in a TO-126 power package, rated for 60V and 2A. Commonly used in audio amplifier output stages, motor control and general-purpose power switching.

In Stock

Transistor BC547

Transistor BC547 2

Transistors

Transistor BC547 NPN, 0.1A TO-92

Reference:

TRBC547

The BC547 is a high-performance NPN Bipolar Junction Transistor (BJT) in a TO-92 package. Optimized for small signal amplification and low-power switching in Arduino, ESP32 and general-purpose DIY electronics.

In Stock

Transistor BC208 NPN Silicon

Transistors

Transistor BC208 NPN Silicon

Reference:

TRBC208

The BC208 is a classic NPN Silicon general-purpose transistor in a plastic TO-106 package.

In Stock

Transistor 2SC2236 NPN, 1.5A TO-92

Transistors

Transistor 2SC2236 NPN, 1.5A TO-92

Reference:

TR2SC2236

The 2SC2236 is a high-current NPN Bipolar Junction Transistor (BJT) in a TO-92 package. Engineered for driving relays, motors and other moderate-power loads in switching applications.

In Stock

Transistor BC323 NPN, 60V, 5A, 0.8W, TO-39

Transistors

Power Transistor BC323 NPN, 5A TO-39

Reference:

TRBC323

The BC323 is an NPN Bipolar Junction Transistor (BJT) in a rugged TO-39 metal can package, rated for up to 5A collector current at 60V. Suited for switching and driver stages that need more current handling than a small-signal TO-92 part can offer.

Last items in stock

Transistor 2N3563

Transistors

Transistor 2N3563 NPN, 0.05A TO-106

Reference:

TR2N3563

The 2N3563 is a silicon NPN Bipolar Junction Transistor (BJT) in a TO-106 package. Designed as an RF/IF small-signal transistor for high-frequency amplifier and oscillator stages.

Last items in stock

Power Transistor BDW51 NPN, TO-3

Transistors

Power Transistor BDW51 NPN, TO-3

Reference:

TRBDW51

The BDW51 is a high-power NPN Bipolar Junction Transistor (BJT) in a robust TO-3 metal package. Designed for heavy-duty linear amplification and power supply applications requiring superior thermal dissipation and reliability.

Last items in stock

Transistor 2N697

Transistors

Transistor 2N697 NPN, 0.5A TO-39

Reference:

TR2N697

The 2N697 is a classic NPN medium-power silicon switching transistor in a hermetic TO-39 metal can package. Originally a JAN military-qualified part, it is still used today in general-purpose switching, driver and small-signal amplifier circuits.

In Stock

Transistor ACY17 PNP, TO-5

Transistors

Transistor ACY17 PNP, TO-5

Reference:

TRACY17

The ACY17 is a PNP Germanium Transistor in a classic TO-5 metal package. A medium-power device ideal for vintage audio amplification, switching applications, and restoration of period electronic equipment.

Last items in stock

Transistor BF194 NPN RF/IF, 30mA TO-92

Transistors

Transistor BF194 NPN RF/IF, 30mA TO-92

Reference:

TRBF194

The BF194 is a classic NPN BJT in TO-92 package, purpose-designed for RF and IF amplification at 455kHz (AM) and 10.7MHz (FM). Industry standard for portable radio receivers, with extremely low internal capacitance for minimal signal attenuation at radio frequencies.

In Stock

Product added to wishlist

Product added to compare.