Author |
Message |
jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
|
Posted: Sat Feb 25, 2017 1:43 am Post subject:
Sine wave multiplier circuit - any advice? |
|
|
I need a simple multiplier circuit that works with analog sine wave at wide frequency range let's say 10 Hz > 15 kHz. I want the multiple outputs sine wave to be a 0.1, 0.2, 0.3...0.5 x f - so not doubling. Output should be analog.
Could you advice me with that?
Thanks Jurek |
|
Back to top
|
|
|
JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
|
Posted: Sat Feb 25, 2017 11:11 am Post subject:
|
|
|
sine frequency multiplication (including values less than one) is not easy in analog. It may be possible to do with a PLL and some digital dividers, but it will be a large complex circuit if you need sine wave output. Such a circuit also has built in latency which could be very noticeable. Digital dividers could be used, but again, with possible adverse complexity since the output is rectangular and to get sine from rectangular would require serious filtering. Even at that, there would be differences in amplitude between the different outputs. In my opinion, what you're asking is a really a job for digital signal processing. DSP would produce a result with low latency and will be highly accurate in frequency, amplitude and waveform shape.
HTH _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
|
|
Back to top
|
|
|
jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
|
Posted: Sat Feb 25, 2017 1:23 pm Post subject:
|
|
|
Thanks for your advice. Yes it seems like DSP or micro-controller should do the job. Someone also pointed a DDS but all of those are black magic for me.
The thing is a simulation works great so i can't sleep and scratching my head how to make it real:) |
|
Back to top
|
|
|
JovianPyx
Joined: Nov 20, 2007 Posts: 1988 Location: West Red Spot, Jupiter
Audio files: 224
|
Posted: Sat Feb 25, 2017 1:26 pm Post subject:
|
|
|
What method does the simulation use to do it?
I just thought that multiple sine VCOs might do it if they track very very well, but sine VCO isn't trivial either. _________________ FPGA, dsPIC and Fatman Synth Stuff
Time flies like a banana. Fruit flies when you're having fun. BTW, Do these genes make my ass look fat? corruptio optimi pessima
|
|
Back to top
|
|
|
blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24081 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
|
Posted: Sat Feb 25, 2017 1:33 pm Post subject:
|
|
|
Maybe a Bode frequency shifter?
What is a DDS BTW? _________________ Jan
also .. could someone please turn down the thermostat a bit.
|
|
Back to top
|
|
|
blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24081 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
|
Posted: Sat Feb 25, 2017 1:35 pm Post subject:
|
|
|
Or a pitch shifter - depending on what you want to do exactly _________________ Jan
also .. could someone please turn down the thermostat a bit.
|
|
Back to top
|
|
|
jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
|
Posted: Sat Feb 25, 2017 1:36 pm Post subject:
|
|
|
I just connected 4 AC voltage sources with different frequencies and amplitudes and summed with a summing amplifier. That's all. One of the inputs is just a "base" frequency. The whole idea comes to mind to use a sort of additive synthesis as a wave folder circuit. So what you have to do is just changing the amplitudes in a range ~100 mVp each. All four frequency multipliers / dividers outputs its frequencies depended from input sine wave. So any input sinewave frequency will get it's 1-4 "xF" which will be summed together as a folded rich in harmonics waveform. Does it make sense to you? |
|
Back to top
|
|
|
jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
|
Posted: Sat Feb 25, 2017 1:43 pm Post subject:
|
|
|
Blue Hell wrote: | Or a pitch shifter - depending on what you want to do exactly |
Hmm... frequency shifters could be a consideration. Depends how the input sine wave would look after a shift = low or high distortion? |
|
Back to top
|
|
|
Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
|
Posted: Sun Feb 26, 2017 2:53 am Post subject:
|
|
|
Blue Hell wrote: | Maybe a Bode frequency shifter?
What is a DDS BTW? |
DDS stands for Direct Digital Synthesis, like with the Analog Devices AD9833 a chip I use a lot in my diy synthesizer.
edit: typo Last edited by Grumble on Sun Feb 26, 2017 7:51 am; edited 1 time in total |
|
Back to top
|
|
|
jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
|
Posted: Sun Feb 26, 2017 3:14 am Post subject:
|
|
|
Grumble wrote: | Blue Hell wrote: | Maybe a Bode frequency shifter?
What is a DDS BTW? |
DDS stands for Digital Direct Synthesis, like with the Analog Devices AD9833 a chip I use a lot in my diy synthesizer. |
Does that chip need to be programmed? |
|
Back to top
|
|
|
Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
|
|
Back to top
|
|
|
blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24081 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
|
Posted: Sun Feb 26, 2017 5:35 am Post subject:
|
|
|
Grumble wrote: | DDS stands for Digital Direct Synthesis, like with the Analog Devices AD9833 a chip I use a lot in my diy synthesizer. |
Thanks, nice chip :-) _________________ Jan
also .. could someone please turn down the thermostat a bit.
|
|
Back to top
|
|
|
|