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How does a voltage transistor 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.
Can a transistor amplify?
A transistor acts as an amplifier by raising the strength of a weak signal. The DC bias voltage applied to the emitter base junction, makes it remain in forward biased condition. Thus a small input voltage results in a large output voltage, which shows that the transistor works as an amplifier.
What happens to the base of a transistor when the voltage is positive?
If you apply a positive voltage greater than 0.7 V to the base, the emitter diode will be forward-biased and current will flow from the base, through the emitter and to ground. The collector diode will be reverse-biased, and no current will flow through that diode.
When does no current flow through a transistor?
If the base-emitter voltage is below 0.7 V, the transistor is in “cutoff” and no current flows through the emitter or through the collector. That’s it. That’s how a BJT works. The collector-emitter current flow is inherent in the construction of the transistor.
What happens at the junction of two anodes in a transistor?
The junction of the two anodes represents the base of a transistor. If you apply a positive voltage greater than 0.7 V to the base, the emitter diode will be forward-biased and current will flow from the base, through the emitter and to ground. The collector diode will be reverse-biased, and no current will flow through that diode.
What are the limits of a transistor circuit?
The transistor can’t drive the collector to the emitter voltage, so it’s saturated. The limitation of this specific circuit, therefore, is a maximum input voltage of about 1.3 V. At the other end, anything less than 0.7 V causes the transistor to go into cutoff.