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How to design a frequency synth?


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  • How to design a frequency synth?

    I'm not much of an "electrical engineer" but the required courses in my CS degree have given me enough to [albeit just barely] understand a few things, so don't judge me if what I ask is complete nonsense.
    I'm trying to develop a circuit in which a high state is driven to something at a frequency (eg 50Hz). This way, the "on" state of the aforementioned something is when it is getting that signal at the frequency and off is no signal. The tricky thing is that the frequency must change and there are more than one of these "somethings" to be driven, by a limited number of signals.
    My thought was to use something like how PWM works, except I would need a component to which you could write a PWM signal that it would then duplicate (upon an enable signal). How can this be achieved? What would be a better approach?
    I wonder if I can design a frequency synth in many ways. This is some original thoughts. Dose it will work? I can choose high speed clock and divide by N counter (software or hardware) . There are decimal and binary counters and "Fractional N counters". Some use variable clocks using digital or analog Voltage control. Others are simply various integer multiples of lowest output frequency. If I need a CMOS binary counter maybe I can create ~50Hz easily from a simple CMOS clock at 50KHz and 2^10 "CMOS binary counter" In software use a single or double precision counts and many embedded chips have hardware counters. The output can be enabled and programmed by input states.
    Kynix synth's are used everywhere from digital radios, TV's, clocks, watches, microwave, and telemetry channels. Such as 1pps from GPS signals.(see datasheet at: KY32-MC12093MNR4G)
    And I need more precision, ceramic or watch oscillators can be used or quartz.
    PWM is generally a fixed frequency and phase is modulated 0 to 100% to synthesize a linear on off switch. These are used in power supplies, class D audio amps and many other applications.
    Without more details I hope this triggers some key words to search for.

    I also want to build a MOOG synthesizer instead. The requirements are understated. in this case I use a VCO with different waveforms and filters to create a single tone using a calibrated VCO and DAC. or use one chip per octave . Then this chip for a smart VCA. http://www.synthtech.com/cem/ssm2045.pdf
    Scrap the idea and learn to use the free MIDI synth on an old PC and use a custom weighted 88 key board to play the synth using the MIDI port for key input. Or simply buy an AXIOM keyboard and play on your Mac AIr in minutes with Darth Vader sound effects singing.
    That's all folks.
    Thank everyone for giving any comments.