amplifier: Why do we use transistor as an amplifier?

Replies

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  vissin

  While a transformer can only amplify either voltage of current a transistor can be used to amplify power.
  
  Meaning, if you use a transformer to amplify voltage current drops keeping power in secondary and primary as same (ignoring losses) and conversely if you use a current transformer it's the voltage that gets adjusted accordingly to keep power constant.
  
  Further have you ever tried to compare the size and the weight of a transformer to that of a transistor.
  
  PS: These days transistors are mainly (in general) used as switches and not as amplifiers. We use Op-amps for amplification purposes.
• 

  manju4vk

  as you already know if beta is high, collector current which is the o/p current is also high, even when base current is low(i/o current).
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  naibrah

  the work of the transformer is not amplification,because the power remains the same (negleting losses),so do not consider it as an amplifier.When we talk of an amplifier,there is always boost of the input power.That the role of transistor and other IC which are just cascaded transistor.In fact,one said ,transistor the the best creation made in the electronics domain
• 

  vissin

  transfomer

  i have used #-Link-Snipped-# for amplification purposes,have you suggest me other Op-amps circuit ,kindly for your suggest

  OP07 is growing rather primitive. It is what they teach you at school but what you seldom use in practice (However, the underlying theory still holds).
  
  For OpAmps that suit your purpose well you only need to google. Your choice may depend on such justifications as whether you are working with single or dual supply, and OpAmp parameters such as offset voltage.
  
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  arunbasillal

  A transofrmer do not actually amplify siganls. A transformer just transfers power between two ciruits. Its a passive deive. while a transistor is a active device. It got some brain and it can amplify signals by transferring signals for a low resistance circuit to a high resistance one.
  So a transformer cant replace a transistor
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  nitin kakria

  naibrah

  the work of the transformer is not amplification,because the power remains the same (negleting losses),so do not consider it as an amplifier.When we talk of an amplifier,there is always boost of the input power.That the role of transistor and other IC which are just cascaded transistor.In fact,one said ,transistor the the best creation made in the electronics domain

  i have been asked to work on the project,transistor as an amplifier,so what are the materials required for that?
• 

  ekshe

  why do we use amplifier?