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2N3055 Transistor: How to Use it, Features, And More!

2N3055 transistor is in a group of electronic transistor devices. The original 2N3055 works best as a low-powered simple switching device. Also, It is a silicon NPN power transistor that is affordable and available suited for many applications circuits

This 2n3055 general-purpose switching transistor also has excellent amplifying features. The transistor is a superb solution to audio amplifiers with these good amplifying features and an almost linear gain.

This article discusses the 2N3055 silicon NPN transistor, its features, and how to use it.

What is a 2n3055 Transistor?

2n3055 is a general-purpose NPN transistor. It is current-controlled. Therefore, any small current present at the base terminal controls a chunk of energy in the remaining terminals. Also, conduction occurs when the movement of electrons and the charge carriers. 

low-power transistors in metal cases

(low-power transistors in metal cases.)

2n3055 Transistor Pin Configuration

three-pin transistors

(three-pin transistors.)

2N3055 Transistor Features

  • Firstly, this transistor is a medium power transistor with a very safe operating area.
  • Second, the2N3055 is an NPN complementary device that comes in a TO-3 case style.
  • Thirdly, its total power dissipation is 115W with the maximum amount of current flow through the base terminal being 7A DC.
  • Additionally, 2N3055 has a DC current gain(hFE) of up to 70A, hence improving the transistor linearity.
  • The maximum rating of the voltage across the base and emitter is 7V DC. While the voltage rating across the collector and base is 100V DC.
  • Further, the maximum current in the collector pin of the transistor runs at 15A DC. While the maximum voltage across the collector and emitter is 60V DC.
  • The 2n3055 TO-3 case style transistor’s also has a low collector-emitter saturation voltage.
  • Lastly, the 2N3055 transistor has an ambient operating temperature range of -65⁰ C to +200⁰ C.
a TO-3 style case transistor

(a TO-3 style case transistor.)

How to use a 2n3055 Transistor.

Circuit Example

You can use the 2n3055 transistor in any bipolar transistor’s application. However, we will use a simple application circuit to understand how the transistor operates entirely.

You will learn about the 2n3055 transistor as a switching device propelling a motor in a typical emitter configuration.  

2N3055 electrical circuit

  (2N3055 electrical circuit.)

Note: The trigger source and power source must share a common terminal for the circuit to work.

Circuit Explanation

From the circuit, the motor acts as the load. The gate signal in the course has a button that, if triggered, turns the transistor ON.

Next, you should place a base resistor in the circuit just after the button. This resistor works by limiting the electric signals flowing through the base. 

When there is no power supply in the circuit, the button remains open; thus, no current flows through the transistor’s base. As a result, the entire supply voltage of 20v(V1) is recorded.

But, when you push the button, the 5v(V2) voltage forms a closed loop with the base and emitter terminals. This creates a complete path for the base current to flow through the transistor, rotating the motor. 

On the other hand, when you release the button, the base current drops to zero, turning OFF the transistor. The transistor lacks collector current and is in high resistance during this state, causing the motor to stop rotating.

2N3055 Transistor: transistors in metal cases

(transistors in metal cases.)


The application areas of the 2N3055 transistor’s ;

  • Power switching and in an amplifier circuit.
  • Regular circuits and signal amplifiers.
  • Pulse WIdth Modulation (PWM) applications.
2N3055 Transistor: a photo showing transistors

(a photo showing transistors.)


We hope this article answered your 2N3055 transistor’s-related questions. Also, for any questions regarding this or any of our work, kindly don’t hesitate to contact us. Our team is always ready to help!

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Emma Lu
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