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A: Transistors are really voltage amplifiers since the effect is voltage across a load. Using beta as a means to calculate gain is an approximation. basically is the ratio emitter resistor and collector resistor with no load
No. Transistors (bipolar junction types, what most people think of as "transistor") are considered to be current devices.
Although it's possible to specify a transconductance (output current/input voltage), this has not been done since the earliest days of transistor theory, and you will have trouble actually finding a transconductance specification in data sheets.
Current gain is (output current/input current).
In a common emitter circuit, this is (collector current/base current), known as hfe or "beta", with ranges from as low as 10 for high-current devices to high hundreds for low-power audio types.
In common base, it's (collector current/emitter current), and it's just a bit less than 1.0, typically 0.95 to 0.999. This is known as hfb or "alpha".
In common collector, it's (base current/emitter current), known as hfc, with about the same values as hfe.
The exceptions are the obsolete point-contact types of the 1950s/early 1960s, and the various types of field-effect/MOS devices known variously as FETs, JFETs, IGFETs and MOSFETs.
The field-effect/MOS devices have very low/zero input current, so they are not specified for current gains.
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∙ 10y ago
Wiki User
∙ 15y agoyou need to do AC analysis to find out the amplifier gain. find AC and DC analysis in wikianswers.com
Wiki User
∙ 11y agoThe ratio between the output current and input current or ratio between the output current and input voltage is measure of transistor gain
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What is the voltage gain of the 2n2222 amplifier?
A: The gain of a transistor is not linear and even that varies from component to component. The gain can vary greatly depending on the Ic current and the load. Manufactures only give out a typical gain for a particular current. As a rule the lower the Ic current the higher the gain. To really find out what a particular transistor characteristics are a tektronik curve tracer is used.
What is the current gain value of BC 148 transistor?
The hFe (current gain) on the BC148 ranges from a minimum value of 20 to 100, depending on collector current, with a maximum value of 300.
What should be the value of collector current in terms of DC gain if transistor is in saturation mode?
DC current gain is collector-emitter current divided by base-emitter current. In linear mode, gain is beta, or hFe. In saturation mode, however, the transistor is over-driven and you can no longer relate collector-emitter current to base-emitter current. The transistor operates like a switch, and collector-emitter current is a function of voltage and load impedance only. (Ignoring the relatively small voltage drop.) To maintain saturation mode, the collector-emitter current must be smaller than the base-emitter current times hFe. Often, it is several times smaller, because hFe can vary from transistor to transistor, and your design must account for this variability.
What is the use of transistor in water level indicator?
It is used to amplify the current. The common-emiiter amplifier is designed so that a small change in voltage (Vin) changes the small current through the base of the transistor; the transistor's current amplification combined with the properties of the circuit mean that small swings in Vin produce large changes in Vout. Various configurations of single transistor amplifier are possible, with some providing current gain, some voltage gain, and some both.
Why does a CE amplifier have a high gain?
GAIN is a function of load current but basically a small current in the base will make a big change of collector current therefore making a transistor a voltage amplifier as opposed to a current amplifier
How do you calculate the current gain of a transistor JFET?
FETs don't have current gain as no current flows through the gate. The gain of a FET is a voltage gain and is called mu.
What is composite transistor?
A Darlington transistor is a composite transistor. The definition is a combination of two or more transistors that have the purpose of increasing the current gain.
What is the voltage gain of the 2n2222 amplifier?
A: The gain of a transistor is not linear and even that varies from component to component. The gain can vary greatly depending on the Ic current and the load. Manufactures only give out a typical gain for a particular current. As a rule the lower the Ic current the higher the gain. To really find out what a particular transistor characteristics are a tektronik curve tracer is used.
What is the difference between a transistor used as a switch and an amplifier?
A transistor used as a switch is operated in saturated mode, where the ratio of base-emitter current over collector-emitter current is far more than hFe, or beta gain. The transistor is either fully on or fully off in this mode. A transistor used as an amplifier is operated in linear mode, where the ratio of base-emitter current over collector-emitter current is equal to or less than hFe, or beta gain. The transistor is partially on in this mode, and is operating as a current controlled current sink.
What is the current gain value of BC 148 transistor?
The hFe (current gain) on the BC148 ranges from a minimum value of 20 to 100, depending on collector current, with a maximum value of 300.
What are the instruments for the study of the gain of a two stage RC Coupled transistor amplifier?
depends on whether you would like calculate or measured results. if you want calculated resulted, then your best bet would be to use an oscilloscope. if you want calculated results, then there are formulas for finding out the voltage, current, impedance, and individual results from each component using the capacitive reactance, voltage, and type of transistor. are you using a summing transistor, inverting amplifying transistor, amplifying transistor, or a different transistor? also are you using DC or AC voltage or current? you need to tell me what type of transistor you are using?
What should be the value of collector current in terms of DC gain if transistor is in saturation mode?
DC current gain is collector-emitter current divided by base-emitter current. In linear mode, gain is beta, or hFe. In saturation mode, however, the transistor is over-driven and you can no longer relate collector-emitter current to base-emitter current. The transistor operates like a switch, and collector-emitter current is a function of voltage and load impedance only. (Ignoring the relatively small voltage drop.) To maintain saturation mode, the collector-emitter current must be smaller than the base-emitter current times hFe. Often, it is several times smaller, because hFe can vary from transistor to transistor, and your design must account for this variability.
What is the alpha beta teta of a bipolar junction transistor?
alpha is the common base current gain = Ic/Ie.beta is the common emitter current gain = Ic/Ib.
What is the voltage gain and current gain for a voltage follower?
In a voltage follower, voltage gain is 1, with an offset of VB-E, and current gain is hFe, limited, of course, by the available current in the supply and by the rating of the transistor.
What is DC load line of a transistor?
A: A transistor has voltage gain as base current is allow to flow. If the load is constant then a DC mirror azimuth path can be plotted as a function of base current and collector current and that is the load line
What is the use of transistor in water level indicator?
It is used to amplify the current. The common-emiiter amplifier is designed so that a small change in voltage (Vin) changes the small current through the base of the transistor; the transistor's current amplification combined with the properties of the circuit mean that small swings in Vin produce large changes in Vout. Various configurations of single transistor amplifier are possible, with some providing current gain, some voltage gain, and some both.
Why does a CE amplifier have a high gain?
GAIN is a function of load current but basically a small current in the base will make a big change of collector current therefore making a transistor a voltage amplifier as opposed to a current amplifier
