0
How do you identify the collector and emitter terminals of a transistor?
Wiki User
∙ 13y ago
Most Digital Multi-Meters (DMM's) have a diode test function the symbol looks something like this >| (picture the greater than sign as a black triangle pointing to and touching the redline).
Initially you should practice on a known good transistor, so you'll be able to tell if you have a bad one.
1) Ensure the transistor is out of circuit.
2) Set the DMM to the diode function.
3) Touch the positive (red) and negative (black) probes to any two leads on the transistor until you get a reading other than infinity.
4) Once you get a reading leave one of the probes on one of the leads (it doesn't matter which one).
5) Take the other probe and touch the third lead. If you don't get a reading other than infinity go back to step 4, this time leave the other probe on the lead it was originally on, when you got the reading other than infinity.
6) Now take the other probe and touch it to the third lead, you should get a reading other than infinity. If not, go back and repeat steps 3-6, but start with 2 different leads, until you can leave 1 lead in place and get a reading other than infinity on the other 2 leads.
7) If you kept the Positive lead in place you have an NPN transistor. If you kept the Negative lead in place you have a PNP transistor.
8) The probe you left in place denotes the Base.
9) On the probe that you swapped, the lead with the lower reading is the Collector and the lead with the higher reading is the Emitter.
Wiki User
∙ 13y ago
Wiki User
∙ 11y agoThe best way to identify the base (and the Collector and the Emitter for that matter) is by looking at the datasheet for the device's part number. Beyond that, it gets complicated. The second best way would be to use a transistor curve tracer, determine if the device is PNP or NPN, you'll essentially get little to no gain with a PNP having the curve tracer set to NPN. Then by measuring the gain (beta) with the collector and the Emitter first one way, then swapped, whichever way you measure the gain as highest, you'll have all 3 leads of the transistor correctly identified thru the terminals of the curve tracer.
Wiki User
∙ 11y agoFor the identification of the transistor leads when you were only given with a resistance measuring device follow this procedure.
as we know that irrespective of the first and the third leads the middle one always represents base. now measure resistance between 1-2 and 2-3 (say a and b)
we know that for any transistor the emitter -base junction is forward biased and the base-collector junction is reverse biased. So, we can conclude that emitter-base junction has a very low forward resistance when compared to the large values of collector base junction.
so if ,
a>b --- 1-collector, 2-base, 3-emitter
a
Add your answer:
Earn +20 pts
What happens when emitter and collector of a transistor are short?
The transistor acts like a normal pn diode. in NPN transistor the both n i.e.,collector and emitter ane shorted then they become a n and other is p so pn diode is formed. When the emitter and the collector of a transistor are short, the emitter current =the collector current.
What are the parts of a transistor?
The emitter, the base, and the collector are parts of a transistor.
What are the parameters of a transistor?
# parameter are usually the base current ib,collector current ic,emitter current ie,collector emitter voltagevce,base emitter voltagevbe,collector base voltagevcb which decide the operation &output of the transistor
What is transistor action?
The transistor has three regions, emitter,base and collector. The base is much thinner than the emitter while the collector is wider than both. However for the sake of convenience the emitter and collector are usually shown to be of equal size. The transistor has two pn junctions that means it is like two diodes. The junction between emitter and base may be called emitter-base diode or simply the emitter diode.The junction between base and collector may be called collector-base diode or simply collector diode. The emitter diode is always forward biased and the collector diode is always reverse biased.
What do you called the center element between the emitter and collector in a transistor?
The base.
What are the three terminals of a transistor?
Emitter, Base, Collector.
How can you identify the emitter of transistor SL100?
The SL100 transistor has a TO-39 case. In the TO-39, the emitter is closest to the tab, and the collector is furthest away from the tab.
What is the usage of third terminal in transistor?
There are three terminals on a transistor. Some have four, where the fourth is a screen.The normal three are Emitter, base and collector. The Emitter emits electrons, the collector collects them and the base controls the flow.
Why a transister has three terminals?
Because there are three components within a transistor... An emitter, a base and a collector. Think of it like shining a torch at a mirror. The the torch is the emitter, the mirror is the base and the reflected beam is the collector.
What happens when emitter and collector of a transistor are short?
The transistor acts like a normal pn diode. in NPN transistor the both n i.e.,collector and emitter ane shorted then they become a n and other is p so pn diode is formed. When the emitter and the collector of a transistor are short, the emitter current =the collector current.
What are the parts of a transistor?
The emitter, the base, and the collector are parts of a transistor.
Can you use transistor as diode?
its the simplest thing to do. There are three legs in a transistor, one each of collector, base and emitter. So if you need to use it as a diode, just connect either collector-base or emitter-base. Say, if you use an NPN transistor, then the base region will be the anode of diode and emitter or collector will be the cathode of the diode.
How does a transistor electronically switch the output on?
A transistor can electronically switch the output by controlling the flow of current between its two terminals, called the collector and emitter. It has a third terminal, called the base, which acts as a control input. When a small current is applied to the base terminal, it influences the flow of current between the collector and emitter terminals, effectively turning the transistor "on" or "off" and allowing it to change the output state.
What are the parameters of a transistor?
# parameter are usually the base current ib,collector current ic,emitter current ie,collector emitter voltagevce,base emitter voltagevbe,collector base voltagevcb which decide the operation &output of the transistor
Is a diode like a transistor?
No. A diode is not like a transistor, and a transistor is not like (two) diode(s). Taken in isolation, the emitter-base and collector-base junctions of a transistor appear to be diodes, but they are coupled together so that the base-emitter current affects the collector-emitter current.
What are the three terminals of transitor?
base, emitter, collector
What is darlington configuaration?
A Darlington pair uses two transistors connected to behave as a single transistor with a very high current gain (beta). Transistor-1 has its collector connected to the collector of transistor-2. Transistor-1 has its emitter connected to the base of transistor-2. The base of transistor-1 with the emitter and collector of transistor-2 is used as a single transistor.
