What is meant by gain in transistor?
bipolar transistors The current gain for the common-base configuration is defined as the change in collector current divided by the change in emitter current when the base-to-collector voltage is constant.
Why do transistors have gain?
The current gain of the transistor is used not only to set up the bias conditions for the circuit design, but also to ensure that there is sufficient gain within the circuit to give the overall required function.
Why do we need to test a transistor?
Remember: This test only verifies that the transistor is not shorted or open, it does not guarantee that the transistor is operating within its designed parameters. It should only be used to help decide if you need “replace” or “move on to the next component”.
What does negative gain mean?
Negative gain means the output is inverted from the input. For the gain to be negative, the output would have to go down when the input goes up, which is clearly not happening in your case.
Which of the main types of transistor has the highest gain?
the power gain is highest in Common emitter: This transistor configuration is probably the most widely used. The circuit provides a medium input and output impedance levels. Both current and voltage gain can be described as medium, but the output is the inverse of the input, i.e. 180° phase change.
What is hFE value of a transistor?
hFE of a transistor is the current gain or amplification factor of a transistor. hFE (which is also referred to as β) is the factor by which the base current is amplified to produce the amplified current of the transistor.
What is the difference between HFE and HFE?
hfe and HFE are two different, but related, characteristics of a bipolar transistor. hFE is the short circuit (vCE=0) forward current ratio (also known as h21) at a specified DC bias (which must be stated for each value of hFE). hfe is the small signal AC gain at a specified bias, and is frequency dependent.
What is HFE value?
The hFE is normally seen to be a constant value, normally around 10 to 500, but it may change slightly with temperature and with changes in collector-to-emitter voltage. Check the transistor’s datasheet for the hFE value in its specifications. Note that hFE may refer to DC or AC current gain.