EMRFD Message Archive 10164

10164 2014-07-20 15:57:25 harizyacine transistor amplifier Message Date From Subject Hi, Please, I am looking for simple transistor amplifier circuit conducts and amplifies only one half of the input cycle without diode, is it possible ? thank you Thinking about the theory a Class B amplifier would probably do this. By altering the bias the transistor will amplify a full cycle (Class A), a half cycle (Class B) or less than a half cycle (Class C). Try this for a better explanation:https://www.youtube.com/watch?v=c6cmkm3UPUIPeter DL8OV What you are looking for is a Class B amplifier.  You will need to bias it so that it only conducts for the half-cycle that you are looking to amplify. Hi, thank you for your reply, if you add more explication you mean class B can amplifies half signal cycle only and biasing transistor can remove side of the signal and about the signal where ever it’s size was ? Yes within reason/overloading.  If the transistor is biased so it barely conducts. When signal goes one way it will completely cut off so no conduction and thus no gain. When signal goes other way it will bias transistor on to greater or less amount depending on the amplitude. That will produce gain in circuit, on just the one half of the signal.   That's the nub briefly.   Cheers Will ZL1TAO       Sent: Tuesday, July 22, 2014 at 11:58 AM Hi,  ok , but if we consider that signal is RF I think it’s size will be small and such amplifier (class B) will not make it pass in one direction removing side of the signal , I think I have to use another transistor circuit or other proposition of the same circuit thanks If the RF frequency is high enough some will leak across anyway. What kind of frequency and voltage level is the signal? Does it extend to DC? How linear does the output need to be? A single transistor shunt feedback amplifier will probably do what you want if it is biased into class B. On 22 Jul 2014 17:12:12 -0700, you wrote: >Hi, > ok , but if we consider that signal is RF I think its size will be small and such amplifier (class B) will not make it pass in one direction removing side of the signal , I think I have to use another transistor circuit or other proposition of the same circuit > thanks Hi, thank you for your reply  the frequency is about 25Mhz and the voltage  of the signal …et I don’t know the exactly but please,  if you consider some values generally then I can know how  the way is and the form of the circuit , I thinking to use resistor between the collector the base for  biasing the transistor  base if that’s compatible with the circuit thanks