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How much current can a transistor switch?
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.
When a transistor works as switch what is its collector voltage?
NPN Transistor as a Switch When a sufficient voltage (VIN > 0.7 V) is applied between the base and emitter, collector to emitter voltage is approximately equal to 0. Therefore, the transistor acts as a short circuit. The collector current VCC / RC flows through the transistor.
Why is FET preferred over BJT?
Since this input impedance is considerably higher than that of BJTs, FETs are preferred over BJTs for use as the input stage to a multistage amplifier. One class of FETs (JFETs) generates lower noise than BJTs. FETs are more temperature stable than BJTs. FETs are generally easier to fabricate than BJTs.
What is the base current of a silicon transistor?
For silicon transistor, V BE = 0.7 V Therefore, as the base current is greater than 56.8 micro ampere current, the transistor will be driven to saturation i.e., it is fully ON, when 5V is applied at the input. Thus, the output at the collector becomes approximately zero.
How do you use a transistor as a switch?
To use a transistor as a switch, all you have to do is increase the current at the base terminal to a certain level, and the transistor will go into a state commonly known as “saturation.”
How does a Darlington transistor work as a switch?
Darlington Transistors simply contain two individual bipolar NPN or PNP type transistors connected together so that the current gain of the first transistor is multiplied with that of the current gain of the second transistor to produce a device which acts like a single transistor with a very high current gain for a much smaller Base current.
What does beta mean on a transistor switch?
Beta — also known as DC current gain — is a ratio relating to how much current gain you can expect through a transistor’s collector terminal given a certain amount of current going into the base terminal. In other words, the base current controls the collector current.