I have built (attached) Super simple FM transmitter www.makezine.com/projects/super-simple-fm-transmitter/
I would really like to better understand how the one achieves FM, as the oscillator circuits are so similar. If anyone can shed some light on this, it would be appreciated.
Any additional info calculations involved would also be most welcome. There are so many novel designs posted, but the authors almost never provide a comprehensive explanation of how the component values are derived or their function in the circuit. The real question is how does this circut actually accomplish frequency modulation: Please use math on me!!!I have this information from another forum
( C2, c1, r1 form a band pass filter to cut out the low and high frequencies (above and below audio frequencies). The capacitors also mix the audio frequencies (audio in) with the rf frequencies of the oscillator.
Additionally, the two resistors (r1and r2) form a voltage divider to bias the transistor.
The middle (capacitor, inductor and resistor) form an LCR tank, the transistor maintains the tank. The tank allows an oscillation to develop and center on a frequency unique to the component values.
The capacitors on the right side are essentially a voltage divider and remove the DC component before sending the signal to the antenna. Also it is more like Colpitts common base oscillator.)
So I'm freshman in EE, i'm trying to understand these explained thing on internet but I cant really catch up. So please use Engineering terminology and Mathematical equations in your analysis
I would really like to better understand how the one achieves FM, as the oscillator circuits are so similar. If anyone can shed some light on this, it would be appreciated.
Any additional info calculations involved would also be most welcome. There are so many novel designs posted, but the authors almost never provide a comprehensive explanation of how the component values are derived or their function in the circuit. The real question is how does this circut actually accomplish frequency modulation: Please use math on me!!!I have this information from another forum
( C2, c1, r1 form a band pass filter to cut out the low and high frequencies (above and below audio frequencies). The capacitors also mix the audio frequencies (audio in) with the rf frequencies of the oscillator.
Additionally, the two resistors (r1and r2) form a voltage divider to bias the transistor.
The middle (capacitor, inductor and resistor) form an LCR tank, the transistor maintains the tank. The tank allows an oscillation to develop and center on a frequency unique to the component values.
The capacitors on the right side are essentially a voltage divider and remove the DC component before sending the signal to the antenna. Also it is more like Colpitts common base oscillator.)
So I'm freshman in EE, i'm trying to understand these explained thing on internet but I cant really catch up. So please use Engineering terminology and Mathematical equations in your analysis