Question: Which Leg Is Which On A Transistor?

How do you identify a leg transistor?

Transistors typically have one round side and one flat side.

If the flat side is facing you, the Emitter leg is on the left, the Base leg is in the middle, and the Collector leg is on the right (note: some specialty transistors have different pin configurations than the TO-92 package described above)..

How transistor is used as a switch?

When using the transistor as a switch, a small Base current controls a much larger Collector load current. When using transistors to switch inductive loads such as relays and solenoids, a “Flywheel Diode” is used. When large currents or voltages need to be controlled, Darlington Transistors can be used.

What is transistor and uses?

Transistors are a three terminal semiconductor device used to regulate current, or to amplify an input signal into a greater output signal. Transistors are also used to switch electronic signals.

How do you know if a transistor is NPN or PNP?

Connect the positive lead of the multimeter to the Base (B) of the transistor and connect the negative lead to the Emitter (E) of the transistor. If it is an NPN transistor then meter should show a voltage drop between 0.45V and 0.9V. If it is a PNP transistor, then it should display see “OL” (Over Limit).

How do transistors work?

A transistor works when the electrons and the holes start moving across the two junctions between the n-type and p-type silicon. … By turning a small input current into a large output current, the transistor acts like an amplifier. But it also acts like a switch at the same time.

Why do transistors have 3 legs?

The transistor has three legs, these are the base, collector and the emitter. … The base of the transistor is used to switch current through the collector and emitter. When the base is between 0V and 0.7V it is switched off and above 0.7V it is switched on allowing the current to flow from the collector to the emitter.

What is NPN and PNP transistor?

In an NPN transistor, a positive voltage is given to the collector terminal to produce a current flow from the collector to the emitter. In a PNP transistor, a positive voltage is given to the emitter terminal to produce current flow from the emitter to collector.

How much current is needed to turn on a transistor?

The diode only needs 0.6V to turn on, more voltage than that means more current. Some transistors may only be rated for a maximum of 10-100mA of current to flow through them. If you supply a current over the maximum rating, the transistor might blow up.

What is transistor in simple words?

A transistor is a type of a semiconductor device that can be used to both conduct and insulate electric current or voltage. A transistor basically acts as a switch and an amplifier. In simple words, we can say that a transistor is a miniature device that is used to control or regulate the flow of electronic signals.

What are types of transistor?

Transistors are basically classified into two types; they are Bipolar Junction Transistors (BJT) and Field Effect Transistors (FET).

How do you tell if a transistor is on or off?

To find out which mode a PNP transistor is in, reverse all of the < and > signs. For example, to put a PNP into saturation VC and VE must be higher than VB. You pull the base low to turn the PNP on, and make it higher than the collector and emitter to turn it off.

How do you read a transistor?

The first digit is the number of leads minus one, so it will be 2 for a bipolar transistor. The first letter will be an S, for semiconductor. The second letter refers to transistor type, such as A for a high-frequency PNP transistor and C for an NPN high-frequency transistor.

Why VCE SAT is 0.2 V?

transistor vce voltage drop It is because both the junctions in the transistor are forward biased at saturation. Under this condition, for npn transistor the emitter to base voltage is ~+0.7V and than between the base to collector ~0.5V (base p, collector n).

What is a transistor symbol?

Transistor Symbols The symbol of NPN and PNP is shown in the figure below. The arrow in the symbol indicates the direction of flow of conventional current in the emitter with forward biasing applied to the emitter-base junction. The only difference between the NPN and PNP transistor is in the direction of the current.

What is transistor with diagram?

Diagram ‘A’ shows an NPN transistor which is often used as a type of switch. A small current or voltage at the base allows a larger voltage to flow through the other two leads (from the collector to the emitter). The circuit shown in diagram B is based on an NPN transistor.

What is PNP transistor?

The PNP Transistor is the exact opposite to the NPN Transistor device we looked at in the previous tutorial. … Then, PNP transistors use a small base current and a negative base voltage to control a much larger emitter-collector current.

How do you identify a Mosfet transistor?

The MOSFETs are the slightly smaller SC-72 (AKA “Single SPA”) package. The polarity of these devices is important, and usually referenced by pin number. To identify the pins, hold the device so that the marking side is factng you, and the legs are pointing downwards.

Which pin is which on a transistor?

Transistors have three pins called emitter (e), base(b) and collector(c). The way that a 2N2222, BC107, BC108 and BC109 transistor symbol maps to the physical device is shown in the diagram below. Different transistors (i.e. transistors with different part numbers) won’t necessarily have the pins in the same order.

How many volts can a transistor take?

Anyways, if you follow the “datasheets here” link, the NPN transistor included with your kit is a SS9013. This particular transistor is rated for a maximum (collector-emitter) voltage of 20V, and a maximum current of 500 mA. This means that you can switch a (small) 12V device with the transistors you have.

Which transistor is best for switching?

Best Transistors: BJTs#1 NPN – 2N3904. You can find most often NPN Transistors in low-side switch circuits. … #2 PNP – 2N3906. For high-side switch circuits, you need a PNP style BJT. … #3 Power – TIP120. … #4 N-Channel (Logic Level) – FQP30N06L.Apr 21, 2014

What are the two basic types of transistors?

There are two most common transistor types today: the Metal -Oxide – Semiconductor or MOS and the Bipolar Junction Transistor or BJT. The MOS is also designated as MOSFET because it is a field effect transistor (FET).