Wrong! Of course, they are!indeed - they are not voltage controllable
However, you should discriminate between (1) ability to tune the frequency with or without influence on the oscillation condition and (2) single-element control yes/no.
Wrong! Of course, they are!indeed - they are not voltage controllable
it was a sarcastic reply to analog kid - (i don't like to repeat myself) i won't cange my statement about most sine wave oscillators being not entirely perfect ← this is what i have encountered so far and no matter what you say it does not change that experience.Wrong!
Ci 139......which circuit is "entirely pefect"? More than that, in electronics, no formula is "entirely" correct...we always have to face simplifications and neglections. And, of course, there is no linear oscillator which produces "clear" sinusoidal waves.it was a sarcastic reply to analog kid - (i don't like to repeat myself) i won't cange my statement about most sine wave oscillators being not entirely perfect ← this is what i have encountered so far and no matter what you say it does not change that experience.
You're going to have to go back and learn the fundamentals. How can you do a complicated design if you don't know squat!!?I used the GIC-resonator, but I got stuck again on how to use the JFET as VCR, when I change the input voltage the resistance of the JFET doesn't really change, and I cannot find the maximum input voltage(Vp). If someone could help.
PS: I am a first-year student, which got a project task to make this, but I have hardly any knowledge about these things.
I just don't know how to operate with a JFET and I can't find the information I need in the internet, so I decided to ask here.You're going to have to go back and learn the fundamentals. How can you do a complicated design if you don't know squat!!?
You said and I quote:I just don't know how to operate with a JFET and I can't find the information I need in the internet, so I decided to ask here.
Of course, we will help you in case of a special problem - however, here we cannot teach you how to use a FET as a variable resistance. You cannot find the information you need in the internet?? I must say - I cannot believe you.I just don't know how to operate with a JFET and I can't find the information I need in the internet, so I decided to ask here.
The attached article might help; it discusses the design of a Wien Bridge oscillator with sine wave output, tuned by a pair of JFET voltage-controlled resistors. Obviously, not a project for beginners...I just don't know how to operate with a JFET and I can't find the information I need in the internet, so I decided to ask here.
This is how my system looks likeHow about showing us a schematic of your attempt to control the resistance by varying the gate voltage. Is it possible that you are applying a voltage to the Gate that is greater than the voltage on the Source. That would explain why you can't get the resistance to change. Oh, by the way you know that the change will be non-linear if you manage to do it correctly.
Yes - that`s what I have told you already in my post#14. Use instead a series combination with a fixed resistor.I think that my Vds voltage is pretty high(-8,36V) and that's why it doesn't work. As I understood i need voltage lower than 100mV.
I noticed the Manhattan style dead bug construction of the VCO and can assure you this is way beyond the capabilities of a 1st year. The use of a 741 in the TS schematic is a dead giveaway that something is wrong because 9kHz is the top end of the frequency range for that part as @Audioguru has often observed.The attached article might help; it discusses the design of a Wien Bridge oscillator with sine wave output, tuned by a pair of JFET voltage-controlled resistors. Obviously, not a project for beginners...
Note that a FET is not the only solution for your task. You also can use an OTA (integrated circuit) or a light-dependent resistor (LDR) instead. It is always good to know the alternatives...This is how my system looks like
by Jake Hertz
by Jake Hertz
by Jake Hertz