How to Test a Transistor
A transistor is basically 2 diodes that share one end., Transistors may operate by junctions or field effects, but both come in two basic types.
Step-by-Step Guide
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Step 1: A transistor is basically 2 diodes that share one end.
The shared end is called the base and the other 2 ends are called the emitter and collector.
The collector accepts an input current from the circuit, but it can't send the current through the transistor until allowed to by the base.
The emitter sends a current out into the circuit, but only if the base allows the collector to pass the current through the transistor to the emitter.
The base acts like a gate.
When a small current is applied to the base, the gate opens and a large current can flow from the collector to the emitter. -
Step 2: Transistors may operate by junctions or field effects
An NPN transistor uses a positive semiconductor material (P-type) for the base and negative semiconductor material (N-type) for the collector and emitter.
On a circuit diagram, an NPN transistor shows an emitter with the arrow pointing out ("Never Points iN" aids remembering).
A PNP transistor uses an N-type material for the base and P-type material for the emitter and collector.
The PNP transistor show an emitter with the arrow pointing in ("Points In Permanently" is the memorizer). -
Step 3: but both come in two basic types.
Detailed Guide
The shared end is called the base and the other 2 ends are called the emitter and collector.
The collector accepts an input current from the circuit, but it can't send the current through the transistor until allowed to by the base.
The emitter sends a current out into the circuit, but only if the base allows the collector to pass the current through the transistor to the emitter.
The base acts like a gate.
When a small current is applied to the base, the gate opens and a large current can flow from the collector to the emitter.
An NPN transistor uses a positive semiconductor material (P-type) for the base and negative semiconductor material (N-type) for the collector and emitter.
On a circuit diagram, an NPN transistor shows an emitter with the arrow pointing out ("Never Points iN" aids remembering).
A PNP transistor uses an N-type material for the base and P-type material for the emitter and collector.
The PNP transistor show an emitter with the arrow pointing in ("Points In Permanently" is the memorizer).
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Joseph Ross
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