shahzad-h Posted August 2, 2006 Report Share Posted August 2, 2006 Hi to all Quote Link to comment Share on other sites More sharing options...
audioguru Posted August 2, 2006 Report Share Posted August 2, 2006 A tank is an inductor and a capacitor in parallel and they resonate.At the resonant frequency their impedance is very high and current transfers back and forth between the inductor and the capacitor. Quote Link to comment Share on other sites More sharing options...
indulis Posted August 2, 2006 Report Share Posted August 2, 2006 You neglected to explain about their impedance values at resonance... and what about "Q"?? Quote Link to comment Share on other sites More sharing options...
audioguru Posted August 2, 2006 Report Share Posted August 2, 2006 Hi Indulis,I think Shahzad is a nooby. I answered him with the basics but if he asks for more details then you be his teacher. Quote Link to comment Share on other sites More sharing options...
shahzad-h Posted August 2, 2006 Author Report Share Posted August 2, 2006 HIdoes tank ckt works like this shown in figure Quote Link to comment Share on other sites More sharing options...
indulis Posted August 2, 2006 Report Share Posted August 2, 2006 No... that waveform looks like a simple RC integrator. At resonance it would oscillate at 1/2*pi*(L*C)^.5 Quote Link to comment Share on other sites More sharing options...
shahzad-h Posted August 2, 2006 Author Report Share Posted August 2, 2006 Hi indulis my main question is that how it produces sharp wave formThanks Quote Link to comment Share on other sites More sharing options...
audioguru Posted August 2, 2006 Report Share Posted August 2, 2006 Anything that resonates with a high impedance makes a sine-wave. A sine-wave is very smooth without sharp edges. Sharp edges on a wave are caused by harmonic distortion because harmonics are added. A sine-wave doesn't have harmonics, just the fundamental frequency. Quote Link to comment Share on other sites More sharing options...
shahzad-h Posted August 3, 2006 Author Report Share Posted August 3, 2006 Hi audioguruAnything that resonates with a high impedance makes a sine-wavecan u please explain this point by mathematical way Quote Link to comment Share on other sites More sharing options...
audioguru Posted August 4, 2006 Report Share Posted August 4, 2006 Hi audiogurucan u please explain this point by mathematical way Quote Link to comment Share on other sites More sharing options...
indulis Posted August 9, 2006 Report Share Posted August 9, 2006 At resonsance, the impedance approches infinity (this of course is impossible... there are always circuit paracitics).From the WWW...The solution to the circuit (which is a second order differential equation) isi(t) = Ae ^+ jωt + Be ^− jωt Considering the initial conditions, solve for A and B.Because there is a complex exponential (thats the "j" part), the solution represents a sinusoidal alternating current. Quote Link to comment Share on other sites More sharing options...
Kevin Weddle Posted August 19, 2006 Report Share Posted August 19, 2006 When calculating a tank, does the high impdeance differ if Xc=Xl=50 ohms from Xc=Xl=100 ohms?When you connect the tank at the collector of a transistor, at DC the collector is at the supply voltage. When you apply the signal, does the peak hit the supply voltage, then go down from there with the size of the ouput signal? In other words, at what DC does the signal hover? Quote Link to comment Share on other sites More sharing options...
audioguru Posted August 19, 2006 Report Share Posted August 19, 2006 When calculating a tank, does the high impdeance differ if Xc=Xl=50 ohms from Xc=Xl=100 ohms?Hi Kevin,Welcome back. ;DThe impedance of a tank circuit at resonance is determined by its Q. Usually it is the inductor's resistance that reduces the tank's Q. Therefore an inductor with a lower reactance would have a lower resistance then the tank would have a higher Q and a higher impedance, but with it the bandwidth is reduced.When you connect the tank at the collector of a transistor, at DC the collector is at the supply voltage. When you apply the signal, does the peak hit the supply voltage, then go down from there with the size of the ouput signal? In other words, at what DC does the signal hover?I haven't looked for many years, but when the DC collector voltage averages at the supply voltage because the resistance of the inductor is very low, then I think the signal voltage at the collector varies above and below the supply voltage. Quote Link to comment Share on other sites More sharing options...
Kevin Weddle Posted August 19, 2006 Report Share Posted August 19, 2006 Thanks for leading me in the right direction concerning the first question. I had hoped a larger reactance might mean a higher impedance. Kind of disappointing. I don't like the second answer either. I was hoping it would just pull away from the supply voltage. Oh well. Quote Link to comment Share on other sites More sharing options...
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