Can Current Travel Both Ways Through A Transistor? - Fixanswer

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).

Can current flow from emitter to base?

There will always be some leakage current, even with the base tied to the emitter

. However, that is “small” in practical applications to the point it is generally ignored. If you apply enough voltage to anything, current will eventually flow.

Does current flow when a transistor is off?

Every semiconductor device has some leakage current, even when the device is “off”. You are getting a bit more that leakage current, because even at a base bias of 0.2v,

some base current will flow, and this will cause collector current to flow

. Like @Math said, the transistor is not OFF in the ideal sense.

How does a transistor control current?

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. When there is no current to the base, little or no current flows between the collector and the emitter. Turn on the base current and a big current flows.

How much current can a transistor handle?

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.

How are transistors connected in a circuit?

To connect the transistor as a switch in a circuit, we connect the output of the device that will switch on the transistor to the base of the transistor. The emitter will connect to ground of the circuit. And the collector will connect to the load that the transistor will turn on and the supply voltage of the circuit.

Does transistor have resistance?

This is why although a transistor has a defined V and I, and their ratio has units of resistance,

we do not say that it has a resistance

, because it will be measured differently by different resistance-measuring devices. Two current measuring devices will give substantially the same reading as each other.

Does a transistor have polarity?

The NPN transistor always has an arrow pointing out. It is clear that the current directions and voltage polarities in PNPs and NPNs are always opposite to each other.

NPN transistors require a power supply with positive polarity with respect to common terminals, but PNP transistors require a negative power supply

.

Can current flow both ways through a Mosfet?

Yes it does conduct in either direction

. Due to the body diode, most discrete MOSFETs cannot block in the reverse direction, but the channel will conduct in either direction when the gate is biased “on”. If you want to conduct and block in both directions you need two MOSFETs in series.

Can transistors amplify?

Transistors are devices that can amplify a signal in a circuit

. It is normally made of germanium or silicon layers. A transistor requires very little current to operate so, releases very little heat.

How can a transistor be used as a switch?

A transistor can be used as a solid state switch.

If the transistor is operated in the saturation region then it acts as closed switch and when it is operated in the cut off region then it behaves as an open switch

. The transistor operates as a Single Pole Single Throw (SPST) solid state switch.

When a CE transistor is cut off?

If the transistor is cut-off,

there is no base current, so there is no collector or emitter current

.

What is the role of transistor in circuit?

transistor, semiconductor device for

amplifying, controlling, and generating electrical signals

. Transistors are the active components of integrated circuits, or “microchips,” which often contain billions of these minuscule devices etched into their shiny surfaces.

Are transistors controlled by voltage or current?

A voltage or current applied to one pair of the transistor’s terminals controls the current through another pair of terminals

. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal.

Is transistor current controlled device?

Basically, a bipolar transistor amplifies a small current entering the base to produce a large collector current.

It is a current-driven device

since the collector current is controlled via the base current.

How do transistors work?

A transistor consists of two PN diodes connected back to back. It has three terminals namely emitter, base and collector. The basic idea behind a transistor is that

it lets you control the flow of current through one channel by varying the intensity of a much smaller current that’s flowing through a second channel

.

Can a transistor handle 12 volts?

yes, you can

. a MOSFET is probably better for switching (cooler, lower current, less waste), but a BJT will work given the currents are within spec.

How do transistors work as amplifiers?

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. This forward bias is maintained regardless of the polarity of the signal.

How much voltage does a transistor use?

Generally speaking, this value is

between . 6 to . 7 volts

for a general-purpose transistor.

How do you connect two transistors together?

Two NPN transistors can be

connected in series with the collector of the lower transistor connected to the emitter of the upper transistor

, figure 4, which provides a way to switch off the load from two different signals. Either input can turn off the load but both need to be on for the load to be on.

Why does a transistor have 3 legs?

The transistor has three legs, these are

the base, collector and the emitter

. The emitter is always connected to 0v and the electronics that is to be switch on is connected between the collector and the positive power supply. The base of the transistor is used to switch current through the collector and emitter.

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.