BD131 BD132 BD135 BD136 BD137 BD138 BD139 BD140 BD237 BD238 TO-126 Transistor Kits 10 Values*10pcs=100pcs Power Transistors for Circuit Design, Repair, Learning & Experiments

Description

Product Overview

The VANXY BD series TO-126 transistor kit delivers a comprehensive collection of power transistors designed for professional and educational use. Each package contains 100 units, organized as ten distinct BJT models with ten pieces per model, providing engineers with the exact parts needed for a wide range of projects. The transistors are housed in robust TO-126 cases that offer superior heat dissipation, allowing reliable operation at higher current levels and ensuring long-term stability in demanding circuits. Key specifications such as collector-emitter voltage, maximum current, and power rating are printed on each component, simplifying selection and reducing the risk of mismatched parts during assembly. The kit includes the following part numbers: BD131, BD132, BD135, BD136, BD137, BD138, BD139, BD140, BD237, and BD238, covering a spectrum of voltage and current capabilities suitable for audio amplification, motor drives, and general-purpose power stages.
All transistors undergo rigorous testing at 125 °C to verify leakage currents and gain stability, guaranteeing that each device meets the advertised hFE range across temperature variations. The silicon wafers are sourced from high-purity silicon crystals, providing low defect density and consistent performance from batch to batch.
The BD series transistors are fabricated using a planar process that optimizes the base width for high gain and low saturation voltage, resulting in efficient power conversion. Their silicon substrate is treated with a passivation layer that protects against moisture and contaminants, extending shelf life and ensuring consistent performance even after prolonged storage.
Reliability testing includes thermal cycling, bias stress, and high-current pulse tests, confirming that each transistor can endure the rigors of industrial environments. The results demonstrate a mean time between failures (MTBF) exceeding 10,000 hours under typical operating conditions, providing confidence for long-term deployments in automation and control systems.

Usage

Design engineers can integrate these transistors into prototype boards to evaluate performance before committing to production-grade components, saving time and material costs. Hobbyists building audio amplifiers will appreciate the low noise characteristics of the BD13x series, which help achieve clean sound reproduction without unwanted distortion. In educational labs, instructors can use the kit to demonstrate transistor biasing, switching behavior, and thermal management, giving students hands-on experience with real components rather than simulations. The robust TO-126 packaging also makes the transistors suitable for motor control applications, where rapid switching and high current handling are essential for reliable operation of DC motors and stepper drives. Repair technicians can replace failed power transistors in legacy equipment with confidence, as the kit provides exact replacements for many common models found in older circuit boards.
When integrating these transistors into printed circuit boards, designers benefit from the standardized TO-126 footprint, which simplifies layout planning and reduces the need for custom footprints. The leads are spaced at 2.54 mm, matching common prototyping boards and allowing easy soldering with standard equipment.
For high-frequency applications, the low parasitic capacitance of the TO-126 package ensures minimal signal distortion, making the BD series suitable for RF front-end stages and fast switching converters. Users can also employ heat-sink clips to further improve thermal performance in demanding environments.

Why Choose Us

VANXY sources each transistor from reputable manufacturers, ensuring that every unit meets stringent quality standards and delivers consistent electrical performance across the entire batch. Our packaging includes detailed heat-sink guidelines and safety instructions, helping users implement proper thermal management and extend the lifespan of their designs.
The bulk value pack reduces per-unit cost dramatically, making it an economical choice for large-scale projects, research labs, and teaching institutions that require multiple copies of the same part.
Customer support is available to answer technical questions, provide substitution advice, and assist with any warranty claims, reinforcing our commitment to after-sales service excellence.
All items are shipped in anti-static bags and sturdy boxes to protect the delicate semiconductor devices during transit, ensuring they arrive ready for immediate use.
Our commitment to sustainability is reflected in the recyclable packaging materials and the energy-efficient manufacturing processes employed at our facilities. By minimizing waste and optimizing production, we deliver high-quality components while reducing environmental impact.
VANXY maintains an extensive inventory management system that tracks each batch from wafer to final shipment, providing traceability and enabling quick response to any quality concerns. This transparency builds trust with our customers and supports compliance with industry standards.
We continuously update our product line based on user feedback, adding new transistor models and improving packaging designs. This commitment to innovation ensures that our customers always have access to the latest components needed for cutting‑edge electronic development.
Our logistics network ensures fast worldwide shipping, with most orders dispatched within 24 hours of purchase. Customers in North America, Europe, and Asia benefit from reliable delivery timelines, allowing them to commence projects without delay.
We continuously update our product line based on user feedback, adding new transistor models and improving packaging designs. This commitment to innovation ensures that our customers always have access to the latest components needed for cutting‑edge electronic development.

Key Features

• Comprehensive ten-type assortment delivers BD131 through BD238, covering a wide voltage range for versatile circuit applications, including audio, motor, and power regulation scenarios, providing engineers with flexibility to prototype and test multiple designs without additional inventory.
• Robust TO-126 packaging ensures superior heat dissipation, allowing safe operation at higher currents and reducing thermal stress during prolonged use. This design choice helps maintain performance stability in demanding environments such as motor drives and high-power audio stages.
• Ideal for educational settings, the kit provides hands-on learning opportunities for students to explore transistor biasing, switching, and amplification concepts in real hardware labs. The inclusion of detailed datasheets and application notes further enhances the teaching experience by linking theory to practical implementation.
• Cost-effective bulk pricing saves up to 70% compared with purchasing individual transistor packs, making it a budget-friendly solution for startups and research teams. The reduced per-unit expense enables larger test matrices and more extensive experimentation without compromising financial constraints.
• Dedicated technical support and a responsive warranty program provide peace of mind, ensuring that any issues are resolved quickly and that customers receive reliable service throughout the product lifecycle. Our team is available via email or phone to address inquiries and guide optimal usage.

FAQ

What is the difference between the BD131 and BD138 transistor models?

The BD131 and BD138 belong to the same BD series but differ primarily in their voltage and current ratings. BD131 is rated for a collector-emitter voltage of 80 V and a maximum collector current of 1 A, making it suitable for low-power audio and signal amplification tasks. In contrast, BD138 supports up to 80 V but can handle up to 2 A of collector current, providing greater power handling for motor control or higher-current amplifier stages. Both share the same TO-126 package, so they can be interchanged on a board when the circuit design accommodates the higher current capability of the BD138, offering flexibility for designers who need to scale performance without redesigning the layout.

Can these transistors be used for high-frequency switching applications?

Yes, the TO-126 package exhibits relatively low parasitic inductance and capacitance, which makes the BD series suitable for switching frequencies up to several hundred kilohertz. For applications such as DC-DC converters, pulse-width modulation (PWM) motor drivers, or RF front-end stages, the transistors can operate efficiently provided that appropriate gate drive circuitry and proper heat-sinking are employed. Designers should also consider the transition time (t_on and t_off) specified in the datasheet to ensure the device meets the timing requirements of the intended circuit. Adding a small series resistor can help dampen ringing and improve overall stability in high-speed switching scenarios.

How should I handle thermal management for these power transistors?

Effective thermal management is critical to maintain performance and reliability. The TO-126 case is designed to be mounted on a heat sink using a thermal pad or insulating washer to improve heat transfer. It is recommended to keep the junction temperature below 125 °C during continuous operation. Users should calculate the required heat-sink thermal resistance based on the power dissipation (P_D) and the ambient temperature, using the formula R_θ = (T_jmax – T_ambient) / P_D. Additionally, ensure adequate airflow around the device and avoid stacking multiple transistors without proper spacing, as this can lead to excessive temperature rise.

What warranty and support options are available for this kit?

VANXY offers a one-year limited warranty covering manufacturing defects and performance issues not caused by improper handling. If a transistor fails within the warranty period, customers can contact our technical support team via email or phone to arrange a replacement. The support staff also provides assistance with circuit design questions, part selection guidance, and troubleshooting advice. All warranty claims require proof of purchase and a brief description of the failure mode. Our goal is to ensure that users receive prompt and effective service, reinforcing confidence in the quality of the BD series transistor kit.

What is the difference between the BD131 and BD138 transistor models?

The BD131 and BD138 belong to the same BD series but differ primarily in their voltage and current ratings. BD131 is rated for a collector-emitter voltage of 80 V and a maximum collector current of 1 A, making it suitable for low-power audio and signal amplification tasks. In contrast, BD138 supports up to 80 V but can handle up to 2 A of collector current, providing greater power handling for motor control or higher-current amplifier stages. Both share the same TO-126 package, so they can be interchanged on a board when the circuit design accommodates the higher current capability of the BD138, offering flexibility for designers who need to scale performance without redesigning the layout.

Can these transistors be used for high-frequency switching applications?

Yes, the TO-126 package exhibits relatively low parasitic inductance and capacitance, which makes the BD series suitable for switching frequencies up to several hundred kilohertz. For applications such as DC-DC converters, pulse-width modulation (PWM) motor drivers, or RF front-end stages, the transistors can operate efficiently provided that appropriate gate drive circuitry and proper heat-sinking are employed. Designers should also consider the transition time (t_on and t_off) specified in the datasheet to ensure the device meets the timing requirements of the intended circuit. Adding a small series resistor can help dampen ringing and improve overall stability in high-speed switching scenarios.

How should I handle thermal management for these power transistors?

Effective thermal management is critical to maintain performance and reliability. The TO-126 case is designed to be mounted on a heat sink using a thermal pad or insulating washer to improve heat transfer. It is recommended to keep the junction temperature below 125 °C during continuous operation. Users should calculate the required heat-sink thermal resistance based on the power dissipation (P_D) and the ambient temperature, using the formula R_θ = (T_jmax – T_ambient) / P_D. Additionally, ensure adequate airflow around the device and avoid stacking multiple transistors without proper spacing, as this can lead to excessive temperature rise.

What warranty and support options are available for this kit?

VANXY offers a one-year limited warranty covering manufacturing defects and performance issues not caused by improper handling. If a transistor fails within the warranty period, customers can contact our technical support team via email or phone to arrange a replacement. The support staff also provides assistance with circuit design questions, part selection guidance, and troubleshooting advice. All warranty claims require proof of purchase and a brief description of the failure mode. Our goal is to ensure that users receive prompt and effective service, reinforcing confidence in the quality of the BD series transistor kit.