Simple Squarewave FM receiver?

[ayashifx55]

Hi everyone,

I am currently working on a FM square wave receiver. Basically it demodulates my signal and outputs the frequency i need (square wave 1khz 1vpp)

I tried using PLL receiver but it does not demodulate square. I am out of choices.

Can anyone suggest a name for a simple square wave receiver (if possible?)

The reason why is i have a LM555 which creates PWM , then it is amplified by a 2 stage amplifier , it transmits through collpitt oscillator.

This PWM will control a servo and it works extremely well but i need a receive to demodulate square wave.....really need your help everyone !!

Thanks.

 

[audioguru]

The amplifier, transmitter and receiver need a wide bandwidth to have a square-wave output.
If your PLL receiver is a normal FM radio then it has de-emphasis which reduces its high frequency response which will mess up a square-wave.
Then the square-wave will be good if the transmitter has pre-emphasis like all FM radio stations use.

 

[ayashifx55]

Someone suggested me to use a simple monostable circuit to demodulate FM and then Low pass filter it and the signal will be what i need....

Does that make sense? thank you very much =)

 

[audioguru]

Why does your project bounce around beween two websites?

Radio remote control is used for model airplanes, cars and boats. They transmit with FM and with PWM modulation. The receiver is also FM and demodulates the PWM to drive servos and electronic speed control of DC motors.

 

[ayashifx55]

Why does your project bounce around beween two websites?

Radio remote control is used for model airplanes, cars and boats. They transmit with FM and with PWM modulation. The receiver is also FM and demodulates the PWM to drive servos and electronic speed control of DC motors.

I know sir, i am trying to design a receiver that will receive square-wave (PWM) signal .... I am asking is there a name of a design or circuit i could look for? Thank you.

 

[audioguru]

Most good model radio control receivers are a super-heterodyne design. Their bandwidth determines how good will be the shape of the PWM waveform. The receivers are mass produced so they are small, lightweight, inexpensive and work perfectly so why bother trying to design your own?

 

[ayashifx55]

I understand sir that receiver / transmitter chips are 10$ or less each but this is for a school project, all i need is a idea or a example so i can base and learn from it.
We are not allowed to used fully circuit built chips like receiver / transmitter .... Thanky ou!!

 

[audioguru]

I have never seen and have never used a tiny FM transmitter or FM radio receiver IC that are used in radio controlled models.
My two model airplanes and helicopter have a receiver with two servos on it, two electronic motor speed control circuits and a gyroscope. It measures 2.5cm by 3cm by 0.5cm high. Its parts are so small that I cannot see a receiver IC. There is a small item in a metal case that might be the entire receiver circuit. It operates at 2.4GHz and its antenna is about 3.5cm long. Its range is over 300m.