The Engineering Projects

Introduction to BD136

Hello Guys! Hope you’re well today. I welcome you on board. In this post today, I’ll walk you through the Introduction to BD136. BD136 is a medium power general-purpose transistor mainly used for switching and audio amplification purposes. It belongs to the PNP transistor family and comes with collector current 1.5A, indicating it can drive loads under 1.5A. The amplification factor ranges from 40 to 250, which means it can amplify the input signal up to 250 times. Both collector-emitter and collector-base voltages are 45V while the emitter-base voltage is 5V, indicating only 5V is required to bias this transistor. I suggest you read this entire post, as I’ll be detailing complete introduction to BD140 covering pinout, working principle, power ratings, applications, and physical dimensions. Let’s get started.

Introduction to BD136

• BD136 is a PNP general purpose transistor mainly used for switching and amplification purpose. It comes with three terminals named as emitter, collector and base.
• The small input current at the base pin is used to produce large output current at the other two terminals. This process is used for amplification purposes.
• It carries amplification factor or current gain 40 to 250, projecting the capacity of the component it can amplify the current.
• BD136 is composed of three layers where one is an n-doped layer and the other two are p-doped layers. The n-doped layer sits between the two p-doped layers.
• The n-layer represents the base pin while the other two layers represent emitter and collector respectively.

• Though both electrons and holes play a critical role in the conductivity, as this is a PNP transistor, here majority carriers are holes in contrast with NPN transistor where majority carriers are electrons.
• In both cases, the base pin is the main terminal responsible for the entire transistor action. The base pin behaves like a valve that controls the number of holes in PNP transistors and electrons in NPN transistors.

• It is important to note that NPN transistors are preferred over PNP transistors for amplification purposes because the electrons’ movement is better and quicker than the mobility of holes in PNP transistors.

BD136 Datasheet

• Before you embed this component in your project, it is wise to have a look at the datasheet of the component that helps you better understand the main characteristics of the transistor.
• Click the like below to download the datasheet of the BD136 transistor.

BD136 Pinout

BD136 comes with three main terminals known as: 1: Emitter 2: Collector 3: Base The following figure represents the pinout of the BD136 transistor.

• All these terminal can be connected with the electrical circuit. Also, these terminals are different in terms of doping concentrations and working ability.
• The base and collector terminals are less doped compared to the emitter terminal. Plus, emitter terminals holds the current of the entire transistor.

BD136 Working Principle

• The working principle of this PNP transistor is simple and straightforward and works like an NPN transistor. Also, in NPN transistor the base pin is positive while it’s negative in PNP transistor.
• The transistor is turned ON and both emitter and collector terminals are forward biased when there is no current at the base side.
• And when there is current at the base terminal, the transistor is turned OFF, projecting both collector and emitter sides are reverse biased.

• Recall NPN transistors are preferred over PNP transistors for amplification purposes because the electrons’ movement is better and quicker than the mobility of holes in the PNP transistor.

Difference between PNP and NPN transistors

• In both transistors, the base pin is the main terminal used to bias the transistor. The base terminal acts like a valve that controls the number of electrons in the NPN transistor and the number of holes in the PNP transistor.

• The main difference stands between the voltages polarities and the current direction. In PNP transistor current flows from emitter to collector terminals while in NPN transistor current flows from collector to emitter terminal.

• Keep this thing in mind, both NPN and PNP transistors are interchangeable only if a bipolar junction transistor is composed of two back-to-back diodes with the base terminal being the common terminal.

 

BD136 Power Ratings

The following table represents the absolute maximum ratings of BD136.

Absolute Maximum Ratings BD136
No.	Rating	Symbol	Value	Unit
1	Collector-Emitter Voltage	Vce	45	V
2	Collector-Base Voltage	Vcb	45	V
3	Emitter-Base Voltage	Veb	5	V
4	Collector Current	Ic	1.5	A
5	Current Gain	hfe	40 to 250
6	Power Dissipation	Ptot	12	W
7	Storage Temperature	Tstg	-55 to 150	C

• The collector-base and collector-emitter voltages are 45V respectively. While emitter-base voltage is 5V indicating only 5V is used to bias the transistor.
• The amplification factor ranges from 40 to 250, demonstrating the transistor capacity to amplify the input signal. The collector current is 1.5A, which means it is capable to support loads under 1.5A.
• The power dissipation is 12 W and storage temperature is -55 to 150C.

• It is important to note that these are defined as the stress ratings. While working with your project, make sure the ratings don’t surpass the absolute maximum ratings, else they can damage the component and thus the entire project.
• Plus, if you apply these ratings for more than the desired time, they can affect device reliability.

BD136 Alternatives

The following are the alternatives to BD136.

• TIP127
• TIP42
• BC157
• 2N3906
• BC556
• BD140
• 2SA1943
• S8550

The BD135 is NPN equivalent to the BD136 transistor.

• While incorporating alternatives into your electrical project, check the pinout of the alternatives. As it’s quite likely the pinout of the alternatives might differ from the pinout of BD136.

BD136 Applications

BD136 is used in the following applications.

• Used for switching and amplification purpose.
• Used to drive loads under 1.5A.
• Used for constructing Astable bistable multivibrators.
• Used in current mirror circuits.
• Used in comparator and oscillator circuits.
• Employed for impedance buffering.
• Used to drive loads under 1.5A.
• Incorporated in H- Bridge circuits.

 

BD136 Physical dimensions

The following figure shows the physical dimensions of the component BD136. That was all about Introduction to BD136. If you have any question, you can approach me in the section below, I’d love to help you the best way I can. Feel free to keep us updated with your feedback and valuable suggestions, they help us create quality content. Thank you for reading this article.

Introduction to BD135

Hi Friends! Hope you’re well today. Thank you for clicking this read. In this post today, I’ll walk you through the Introduction to BD135. BD135 is a general-purpose medium-power transistor that falls under the category of NPN transistors. It is mainly used for switching and audio amplification purposes. It comes with a collector current 1.5A, indicating it can drive loads under 1.5A. Total power dissipation is 12.5W with storage temperature ranging from -55 to 150C. Bear with me for a couple of minutes as in this post I’ll be discussing the complete introduction to BD135 covering pinout, datasheet, working principle, power ratings, applications, and physical dimensions of transistor BD135. Let’s jump right in.

Introduction to BD135

• BD135 is an NPN transistor made-up of silicon material. It is a medium power transistor mainly used for audio amplification and switching purpose.
• This NPN transistor comes with three terminals called emitter, base, and collector. Where small current at the base side is used to produce large current at the other two terminals. This process is used for amplification purposes.
• BD135 carries three layers where one is a p-doped layer and the other two are n-doped layers. The p-doped layer stands between the two n-doped layers.
• In this transistor, the base terminal is positive and represents the p-doped layer while the other two terminals are negative.

• It is important to notice that both electrons and holes play a vital role in conductivity. As this is an NPN transistor, here electrons are majority carriers in opposed to PNP transistors where holes are majority carriers.

• In both cases, however, the base terminal plays the key role to control the overall transistor action.
• In NPN transistor, the base pin controls the number of electrons emitted from the emitter side, and in PNP transistor this base terminal controls the number of holes emitted by emitter which are then collector by the collector side.

BD135 Datasheet

Before employing this component into your electrical projects, it is wise to have a look at its datasheet that will help you get a hold of the main characteristics this element holds. Click below to download the datasheet of the BD135 transistor.

BD135 Pinout

BD135 carries three terminals called: 1: Emitter 2: Collector 3: Base The following figure shows the pinout of the BD135. All these terminals are different in terms of functionality and doping concentration. Emitter pin is more doped compared to the other two terminals. These pins are used for external connection with the electronic circuit.

BD135 Pin Configuration

BD135 transistor is available in the following three configurations: 1: Common emitter configuration 2: Common collector configuration 3: Common base configuration

• Common emitter configuration is used for amplification purposes as it comes with the suitable voltage and current ratings required for amplification.
• The amplification factor or current gain is an important factor of the transistor that demonstrates the capacity of any transistor it can amplify the current. It is a ratio between collector current and base current and is denoted by ß. In this case, the amplification factor ranges from 40 to 250. As this is a ratio between the same element i.e. current it carries no unit.
• The current gain is another important factor that is mainly used to demonstrate the nature of the transistor. It is known as alpha and is denoted by a. It is a ratio between collector current and emitter current. The alpha value is always less than 1, commonly lies from 0.5 to 1.

BD135 Working Principle

• Recall, the base pin is responsible for the overall transistor action. This pin behaves like an electron valve that controls the number of electrons emitted from the emitter terminal.

• The base terminal behaves similarly in the PNP transistor but here it controls the number of holes.
• The small current at the base terminal is amplified and produced across the other terminals during the amplification process.

• And when BD135 behaves like a switch, it changes the small current present at one side of the transistor into a larger current across the remaining terminals.
• As BD135 is an NPN transistor, here the base pin is positive with respect to the emitter terminal and the collector voltage is more positive than the emitter voltage.
• Also, the collector side is connected with the resistor to limit and control the flow of current.

 

BD135 Power Ratings

The following table shows the absolute maximum ratings of BD135.

Absolute Maximum Ratings BD135
No.	Rating	Symbol	Value	Unit
1	Collector-Emitter Voltage	Vce	45	V
2	Collector-Base Voltage	Vcb	45	V
3	Emitter-Base Voltage	Veb	5	V
4	Collector Current	Ic	1.5	A
5	Current Gain	hfe	40 to 250
6	Power Dissipation	Ptot	12.5	W
7	Storage Temperature	Tstg	-55 to 150	C

• These are the stress ratings. Make sure ratings don’t exceed the absolute maximum ratings, else they can damage the component and thus the entire project.

• Also, if these ratings are applied for more than the required time, they can severely affect device reliability.

BD135 Alternatives

The following are the alternatives to BD135.

• BD131
• BD135G
• BD167
• BD137
• BD139G
• BD169
• BD137G
• BD139
• BD165
• It is important to note that… before employing these components in your electrical circuit, check the pinout of the alternatives, as it is likely the pinout of the alternatives differ from the pinout of the BD135. Early due diligence can help you avoid hassle later.
• BD136 is a complementary PNP transistor to BD135.

BD135 Applications

BD135 is used in the following applications.

• Used for amplification and switching purposes.
• Used in Astable and Bistable multivibrators.
• Used in sensor circuits.
• Used to control motor.
• Employed in H-bridge circuits
• Used in an audio preamplifier and amplifier stages.
• Used to drive loads under 1.5A.
• Employed in battery chargers.

BD135 Physical dimensions

The following figure shows the physical dimensions of the BD135 transistor. Looking into these dimension you can evaluate the space required for your electronic project. This is it. I hope you find this article helpful. If you need my help, I’d be happy to contribute in any way I can. You’re most welcome to share your valuable suggestions and feedback in the section below, they help us create quality content. Thanks for reading the article.

Introduction to BD137

Hi Folks! Hope this finds you well. Thank you for stopping by. In this post today, I'll be discussing the Introduction to BD137. BD137 is an NPN medium power transistor mainly employed in switching and audio amplification applications. It is composed of silicon material and comes in the TO-126 package. The collector-base and collector-emitter voltages are 45V and the emitter-base voltage is 5V which details that only 5V is required to bias this transistor and start transistor action. The collector current is 1.5A which documents that it can support loads under 1.5A. Power dissipation is 12.5W and storage temperature ranges from -55 to 150C. Read this entire post, as I'll walk you through the complete Introduction to BD137 detailing pinout, datasheet, working principle, power ratings, applications, and physical dimensions. Let's jump right in.

Introduction to BD137

• BD137 is a medium power transistor that falls under the category of NPN transistors.
• It contains three terminals known as emitter, collector, and base. The small input current at the base pin is utilized to create a large current at the other two terminals.
• BD137 is composed of three layers where one p-doped layer sits between the two n-doped layers. The single p-doped layer represents the base terminal which is positive and the other two terminals represent emitter and collector that are negative.
• As this is an NPN transistor, here current flows from the collector pin to emitter pin while the base terminal controls the number of electrons emitted from the emitter pin which are then collected by the collector pin.

• Though both holes and electrons play a vital role in conductivity, here in this NPN transistor, holes are minority carriers while on the other hand electrons are majority carriers.
• This is opposite in the case of PNP transistors where electrons are minority carriers and holes are majority carriers.

• It is important to note that the NPN transistors are widely used for amplification purposes and are preferred over PNP transistors because the movement of electrons is better than the movement of holes.

BD137 datasheet

While incorporating this NPN transistor into your electrical project, it is better to scan through the datasheet of this component that will help you get a better understanding of the characteristics of the component. To download the datasheet of BD137, click the link below.

BD137 Pinout

BD137 contains three terminals named 1: Emitter 2: Collector 3: Base The following figure shows the pinout of the BD137 transistor.

• These pins are used for the connection with the external circuit. All these terminals carry different doping concentrations and different functionality.
• The collector and base pins are less doped as compared to the emitter pin. Plus, the emitter terminal holds the entire current of the transistor.

Pin Configurations

BD137 is used with three main configurations. 1: Common-base configuration 2: Common-collector configuration 3: Common-emitter configuration

• The Common-emitter configuration is employed for the amplification purposes because it comes with the exact current and voltage required for the amplification.
• The amplification factor is an important factor of this transistor that defines the capability of the transistor it can amplify the input signal that is then produced as output across the other terminals. It is called beta and is denoted by ß. It is a ratio between the collector current and base current.
• The current gain is another important factor that defines the nature of the transistor. It is denoted by a and is known as alpha. It is a ratio between collector current and emitter current. The alpha value is always less than 1, mostly ranges from 0.5 to 1.

BD137 Working Principle

• No matter the transistor is… whether it’s NPN or PNP transistor, the base pin is used to trigger the overall transistor action.
• This base pin controls the number of electrons in the case of NPN transistor while it controls the number of holes in the case of PNP transistor. This base terminal acts as a control valve.

• In this BD137 NPN transistor, here the base terminal is positive with respect to the emitter side and the emitter voltage is less positive than the collector voltage.

• The small input current at the base side is amplified and created across the remaining two terminals during the amplification process.
• And BD137 also acts like a switch, where it changes the small current available at one side of the transistor into much larger current across the other two terminals.
• Plus, the collector side is coupled with the resistor to control and limit the flow of current.

BD137 Power Ratings

The following table shows the absolute maximum ratings of the component BD137.

Absolute Maximum Ratings BD137
No.	Rating	Symbol	Value	Unit
1	Collector-Emitter Voltage	Vce	45	V
2	Collector-Base Voltage	Vcb	45	V
3	Emitter-Base Voltage	Veb	5	V
4	Collector Current	Ic	1.5	A
5	Current Gain	hfe	40 to 250
6	Power Dissipation	Ptot	12.5	W
7	Storage Temperature	Tstg	-55 to 150	C

• The emitter-base voltage is 5V which means it needs only 5V to bias the transistor while collector-base and collector-emitter voltages are 45V.
• Power dissipation is 12.5W which projects that it releases 12.5W energy during the working of this transistor. The DC current gain ranges from 40 to 250 which demonstrates the amount of current it can amplify.
• These are main called stress ratings. Make sure while working with your electrical project these ratings don't surpass the absolute maximum rating or they can badly damage the component.

• Moreover, if these ratings are applied for a maximum period, they can affect device reliability.

BD137 Alternatives

• The BD135 & BD139 are the alternatives to BD137.
• While working with the alternatives, double-check the pinout of the alternatives before using them in your project, as it's quite likely the pinout of the BD137 may differ from the pinout of the alternatives.
• The complementary PNP transistor to BD137 is BD138.

Applications

BD137 is used in the following applications.

• Used to design audio amplifiers and drivers using complementary circuits.
• Used to control motor.
• Employed in an audio preamplifier and amplifier stages.
• Used to support loads under 1.5A.
• Employed in H-bridge circuits.
• Incorporated in battery chargers.

BD137 physical dimensions

The following figure shows the physical dimensions of the BD137 transistor. This will help you audit the space required for the entire project. That's all for now. Hope you find this read helpful. If you're unsure or have any query, you can pop your comment in the section below, I'll help you the best way I can. Keep sharing your feedback and suggestions around the posts we share, they help us create quality content. Thank you for reading this article.

Introduction to BD138

Hi Guys! Hope you’re well today. I welcome you on board. In this post today, I’ll detail the complete Introduction to BD138. BD138 is a PNP transistor that is incorporated in audio amplification and switching applications. It is composed of silicon material and comes in the TO-126 package. It contains three terminals, where small input current across one terminal is used to produce large output current across the remaining two terminals. The collector-base and collector-emitter voltages are 60V with emitter-base voltage 5V that illustrates the amount of voltage it requires to bias the transistor. In this post I’ll walk you through the Introduction to BD138 detailing pinout, working, physical dimensions, applications, power ratings, and alternatives of BD138 transistor. Let’s get started.

Introduction to BD138

• BD138 is a medium-power transistor that is mainly used for amplification and switching applications.
• It contains three terminals known as emitter, collector, and base. During the amplification process, the small current at the base side is used to produce large output current at the remaining terminals.
• BD138 is composed of three layers. The two layers are p-doped that contains one n-doped layer.
• This n-doped layer represents the base pin that is negative and the other two p-doped layers represent emitter and collector respectively that are positive.

• As this is a PNP transistor, here holes are majority carriers.
• Even though both electrons and holes play a key role in the conductivity, here in PNP transistor holes are majority carriers indicating major conductivity process is done by holes while electrons are minority carriers.

• And it is opposite in the NPN transistor where holes are minority carriers and a major part of conductivity is done through the number of free electrons inside a transistor.
• It is important to note that, for amplification purposes, NPN transistors are commonly used instead of PNP transistors, because the movement of electrons is more efficient and quicker than the movement of holes during the conductivity process.

BD138 Datasheet

• Before you incorporate this component into your electronic project, it is wise to have a look at the datasheet of the component that will help you scan through the main characteristics of the transistor.
• Click below and download the datasheet of transistor BD138.

BD138 Pinout

The BD138 carries three main terminals named as: 1: Emitter 2: Collector 3: Base The following figure shows the pinout of the BD138 transistor.

• These three pins come with different functionality and different doping concentration. The emitter terminal contains the entire current of the transistor and comes with more doping concentration in contrast to both collector and base pins.
• These terminals are connected with the external circuits during the construction of any electrical project.
• It is important to note that, no matter the transistor, whether it’s PNP or NPN transistor, in both cases the base pin plays a key role in the overall transistor action.
• It controls the number of holes in the case of PNP transistor and it controls the number of electrons in the NPN transistor.
• Base pin is nothing but a control value that controls the majority carriers during the conductivity process inside the transistor.

BD138 Working Principle

Recall, the base terminal is negative in PNP transistor while it’s positive in NPN transistor. And the base terminal is the part of the transistor that triggers the overall electron action.

• Both collector and emitter pins are forward biased when the base terminal contains no current and in this situation, the component is turned ON.

• And it is turned OFF when base pin carries current and in that case, both emitter and collector pins are reverse biased.

 

BD138 Power Ratings

The following table represents the absolute maximum ratings of the transistor BD138.

Absolute Maximum Ratings BD138
No.	Rating	Symbol	Value	Unit
1	Collector-Emitter Voltage	Vce	60	V
2	Collector-Base Voltage	Vcb	60	V
3	Emitter-Base Voltage	Veb	5	V
4	Collector Current	Ic	1.5	A
5	Current Gain	hfe	40 to 250
6	Power Dissipation	Ptot	12.5	W
7	Storage Temperature	Tstg	-55 to 150	C

• You can witness, both collector-emitter and collector-base voltages are 60V and the emitter-base voltage is 5V which indicates the voltage required to bias the component and start the transistor action.
• The collector current is 1.5A which signals the amount of load this transistor can support. And the power dissipation is 12.5W that illustrates the energy released during the working of this transistor.
• While working with the component, keep this in mind, the ratings don’t exceed the power ratings, otherwise, it can put you in deep trouble by damaging the component or entire project.
• Also, don’t apply these ratings for more than the required time, else they can affect the device reliability.

Difference between NPN and PNP transistors

• Both NPN and PNP transistors work in a similar fashion with a few exceptions.
• In NPN transistor the current flows from collector pin to emitter pin while this is opposite in case of PNP transistor i.e. current flows from emitter to collector pin. In both cases, however, the base terminal is used to bias the entire transistor.

• It is important to notice that, both PNP and NPN components are interchangeable given that the bipolar junction transistor is made up of two back-to-back diodes. And these diodes share a common base terminal.

 

BD138 Alternatives

• The alternatives to BD138 are BD136 and BD140.
• Double-check the pinout of the alternative before employing them into your project. It’s quite likely the pinout of the alternatives may differ from the alternatives of the BD138.
• The complementary NPN transistor to BD138 is BD137.

BD138 Applications

• Used for medium-power amplification and switching applications.
• Used to drive loads under 1.5A.
• Employed in H-bridge circuits.
• Used in Astable and Bistable multivibrators.
• Incorporated in the motor control circuit.

BD138 Physical dimensions

The following figure shows the physical dimensions of the BD138 transistor. These dimensions help you evaluate the space required for your electrical project. That’s all for today. Hope you find this read valuable. If you have any query, you can pop your question in the section below, I’ll help the best way I can. You are most welcome to share your feedback and suggestions, they help us to create quality content as per your needs and requirements. Thanks for reading this post.

Introduction to TIP2955

Hello friends, I hope you all are doing great. In today's tutorial, we are gonna have a look at detailed Introduction to TIP2955. It is a harmonizing silicon power transistor which is designed to use in universal tenacity power amplifications and swapping submissions. It is a PNP transistor and has a casing of TO-247. It is the complementary device for the  TIP3055 NPN transistors. It is used in such applications which need high power input supply. It is a common expedient used in numerous manufacturing schemes where acoustic intensification is obligatory. Its constructions are good-looking much the alike rejecting for the extreme power tolerance that is somewhat smaller. In today’s post, we will have a look at its protection, wreck, fame, applications, etc. I will also share some links where I have allied it with other microcontrollers. You can also get more material about it in comments, I will guide you more about it. So, let’s get started with a basic Introduction to TIP2955. 

Introduction to TIP2955

• It is a harmonizing silicon power transistor which is designed to use in universal tenacity power amplifications and swapping submissions. It is a PNP transistor and has a casing of TO-247.
• This transistor exits into the class of power transistors. Power transistors can endure high power indulgence deprived of any destruction.

• Due to the restrictions of the transistor suite type, it is permanently compulsory that a power transistor is equestrian on an appropriate heat sink in other to bind the device’s maximum rated power deprived of harm.
• This transistor finds extensive use in Power Swapping schemes such as inverters, and output periods of acoustic amplifiers where they are linked in push-pull with a corresponding power transistor type.
• When used in an acoustic amplifier scheme, it is sensible to enterprise the power transistor from a pre-amplifier phase as most power transistors have little current gain.

  Pinout of TIP2955

• These are the main pinout of TIP2955 which are well-defined beneath.

• Pin#	Type	Parameters
  Pin#1	Emitter	The emitter is for an outside enterprise of current.
  Pin#2	Base	The base manages the biasing of the transistor. It caprices the condition of the transistor.
  Pin#3	Collector	The collector is for the current inward movement. It is connected to the load.

  Lest see a diagram of the pinout.

Features of TIP2955

• These are the main features of TIP2955.
  • It is a PNP transistor.
  • Its extreme power Indulgence (dissipation) (Pc) at the collector is 90 Watt.
  • Its extreme voltage at collector and base (Vcb) terminal is 100 volts.
  • Its extreme voltage at collector and emitter terminals (VCE) is 70 volts.
  • It has extreme voltage across emitter and base terminal is 7 volts.
  • Its extreme current at collector point is 15 ampere.
  • Its maximum working intersection temperature is 150 centigrade.
  • Its Changeover Frequency (ft) is 3 MHz.
  • Its onward current transmission ratio (hFE) is 20.

Maximum Ratings of TIP2955

Symbols	Ratings	Parameters
VCEO	60V	These are the voltage across collector and emitter.
VCER	70 V	These are the voltage across collector and emitter.
VCBO	100 V	These are the voltage across collector and base.
VEBO	7V	It is the voltage across emitter and base.
IC	15A	It is the current at the collector.
IB	7A	It is the value of current at the base terminals.
PD	90 W 0.72 W/°C	Total Power Dissipation at TC = 25°C. Derate Above 25°C.
TJ, TSTG	-65 to +150 C	It is working and Storing Connection Temperature Range

Electrical Characteristics

Symbols	Ratings	Parameters
VCEO	60V	These are C-E Supporting Voltage. (IC = 30 mA, IB = 0)
ICER	1mA	It is the collector Cut-off Current. (VCE = 70 V, RBE = 100 ?)
ICEO	0.7mA	It is the collector Cut-off Current. (VCE = 30 V, IB = 0)
ICEV	5mA	It is the collector Cut off Current (VCE = 100 V, VBE (off) = 1.5 V)
IEBO	5mA	It is the emitter Cut off Current. (VEB =7 V, IC = 0)
hFE	20 5	It is the DC current Gain. (IC = 4 A, VCE = 4 V) (IC = 10 A, VCE = 4 V)
VCE	1.1V 3V	These are the Collector-Emitter Saturation Voltage. (IC = 4 A, IB = 0.4 A) (IC = 10 A, IB = 3.3 A)
VBE	1.8V	Base-Emitter on Voltage (IC = 4 A, VCE = 4 V)

TIP2955 as Voltage Regulator

• Now we discuss how it works as the voltage regulator. For this, we discuss the circuit diagram.
• Here is the circuit illustration of a potent 12V regulator that can carry up to 15 A of current. The communal voltage regulator IC 7812 (IC1) is rummage-sale to keep the voltage at stable 12V and three TIP 2599 power transistors in parallel are underwired in series permit style to increase the output current.
• The 7812 can deliver only up to 1A and respite of the current is provided by the series permit transistors. The 15A bridge B1 does the work of rectifying the stepped downcast AC input.
• The C1, C2, and C3 capacitors in this circuit are working as a filter. The 1A fuse F1 defends the IC1 from an excess of current in circumstance if the pass transistors flop. The 15A fuse F2 shields the complete circuit (particularly the pass transistors) from overcurrent.
• When you are working on such circuits which are using current transformers high current consuming bridge circuits this circuitry is expensive and you can try this only if there is a solemn essential.

Applications of TIP2955

• These are particular applications of TIP2955.
  • It is collective tenacity transistor it can be used in different manufacturing projects.
  •  It is used as an Audible Amplifier.

So it was all about TIP2955 if you have any question please ask in comments. Take care until the next tutorial.

Introduction to BD140

Hello Friends! Hope this finds you well. I welcome you on board. Thank you for clicking this read. In this post today, I’ll walk you through the Introduction to BD140. BD140 is a medium power bipolar junction transistor that is mainly used for switching and amplification purpose. It belongs to the PNP transistor category and comes in the TO-126 package. It is made up of silicon material with collector current 1.5A which indicates it can support loads under 1.5A. The collector-base and collector-emitter terminal voltages are 80V and emitter-base voltage is 5V which is used to bias the transistor. In this post, I’ll be detailing the complete introduction to BD140 covering pinout, working, absolute maximum ratings, physical dimensions, alternatives, and applications. Let’s jump right in.

Introduction to BD140

• BD140 is a PNP bipolar junction transistor that is used to drive loads under 1.5A.
• It comes with three terminals known as emitter, collector, and base. The small current at the base side is used to produce large output current at the emitter and collector terminals.
• The reason it is mainly known as a current-controlled device for controlling the input current in contrast to FETs (field-effect transistors) that are voltage-controlled devices.
• BD140 carries three layers where one is the n-doped layer that stands between the two p-doped layers. The n-layer represents the base pin while the other two layers represent the emitter and collector terminals.

• As this a PNP transistor, here majority carriers are holes. Though both electrons and holes are necessary for the conductivity process inside the transistor, here in case of PNP transistor electrons are minority carriers and holes are majority carriers in contrast to NPN transistors where holes are minority carriers and electrons are majority carriers.

• Both NPN and PNP are termed as bipolar junction transistors and are used for amplification and switching purposes.
• NPN transistors, however, are preferred over PNP transistors for amplification purposes. Why? Because the movement of electrons inside the transistor is faster than the movement of holes in the PNP transistor.
• In rare cases, PNP and its complementary NPN are incorporated into a single electrical circuit.

BD140 Datasheet

Datasheet helps you understand the main and common characteristics of the transistor BD140. Before you install this component into your project, check the datasheet to get a hold of the main features of the transistor. Click below to download the datasheet of BD140.

BD140 Pinout

The BD140 consists of three pins named: 1: Emitter 2: Collector 3: Base The following figure shows the pinout of the BD140 transistor.

• These pins are also called terminals which are used for the external connection with the electrical circuit. All these terminals come with different functionality and different doping concentration.
• The emitter terminal is highly doped as compared to collector and base terminals. Moreover, this emitter pin consists of the entire transistor current.

BD140 Working Principle

• Whether it’s NPN or PNP transistor, the base pin is used to control the current. This base terminal controls the number of electrons in NPN transistors, and the number of holes in PNP transistors.
• In the case of this BD140 PNP transistor, when there is no current at the base side, the transistor is turned ON and both collector and emitter pins, in this case, are forward biased.

• And when there is current present at the base side, the transistor is turned OFF, leaving both collector and emitter terminals reverse biased.

Difference between NPN and PNP transistors

• Recall the base terminal is used to bias the transistor in both NPN and PNP transistors. There are, however, differ in terms of current directions and voltage polarities.

• In PNP transistor the flow of current is from emitter to collector terminal while it is opposite in NPN transistor i.e. collector to emitter terminal.

• In PNP transistor the current flows from emitter to collector terminal when a negative voltage supply is given to the base side and current flows from collector to emitter terminal in NPN transistor when positive supply is given to the base pin.

BD140 Power Ratings

The following figure shows the absolute maximum ratings of BD140.

Absolute Maximum Ratings BD140
No.	Rating	Symbol	Value	Unit
1	Collector-Emitter Voltage	Vce	80	V
2	Collector-Base Voltage	Vcb	80	V
3	Emitter-Base Voltage	Veb	5	V
4	Collector Current	Ic	1.5	A
5	Current Gain	hfe	40 to 250
6	Power Dissipation	Ptot	12.5	W
7	Storage Temperature	Tstg	-55 to 150	C

• • These are known as stress ratings. While working with the component, make sure ratings don’t cross the absolute maximum ratings, else they can severely damage the component and ultimately the entire project.
  • The collector-emitter and collector-base voltages are 80V and only 5V are needed for the emitter-base terminals.
  • This 5V voltage indicates that only 5V is required to bias the transistor and start the overall transistor action.

• The collector-current carries 1.5A which signals the amount of loads it can support.
• The power dissipation is 12.5W which illustrates the amount of energy it releases during its operation.

BD140 Alternatives

• The BD136 and BD138 are the alternatives to BD140.
• Before you incorporate these alternatives into your project, check the pinout of the alternatives. At times, the pinout of the BD140 differs from the pinout of the alternatives.
• The complementary NPN transistor to BD140 is BD139.

BD140 Applications

BD140 is used in the following applications.

• Used for amplification and switching purposes.
• Used to drive loads under 1.5A.
• Used in H-bridge circuits and motor control circuits.
• Used in Astable and Bistable multivibrators.

BD140 Physical dimensions

• The following figure shows the physical dimensions of transistor BD140.
• By looking at these dimensions, you can audit the total space required for the entire electrical project and you can install this component in the desired place.

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