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sine wave from dc

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  • Sam Jesse
    Hi I ve been thinking about this for a while and would appreciate some light. Given a 12v battery. what is the process to create a pure sine wave of
    Message 1 of 20 , May 20, 2014
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      Hi

      I've been thinking about this for a while and would appreciate some light.
      Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
      What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

      Thank you


    • Jong Kung
      Sam, This depends on what you are trying to achieve. Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you
      Message 2 of 20 , May 20, 2014
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        Sam,


        This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

        If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

        =====

        Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

        So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


        Jong 

        On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

        Hi

        I've been thinking about this for a while and would appreciate some light.
        Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
        What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

        Thank you


      • Jong Kung
        Sam, Please be aware that many analog sine wave generator circuit (using discrete components) you might find online are NOT true sine wave - but close to
        Message 3 of 20 , May 20, 2014
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          Sam,


          Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

          I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


          They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

          If you are interested, there's much more from other skilled engineers here. 

          =====

          There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


          Jong




          On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

          Sam,


          This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

          If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

          =====

          Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

          So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


          Jong 

          On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

          Hi

          I've been thinking about this for a while and would appreciate some light.
          Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
          What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

          Thank you


        • Sam Jesse
          Jong; Thank you for your generous help. I would rather have a ready sine wave generator. Would DDS with a micro controller allow me to have a sine wave with
          Message 4 of 20 , May 20, 2014
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            Jong; Thank you for your generous help.

            I would rather have a ready sine wave generator. Would DDS with a micro controller allow me to have a sine wave with increasing or decreasing amplitude? i.e. increase in each signal for the first x signals or period then stay fixed at a predetermined amplitude then repeat?

            Would you kindly recommend a Microchip brand uC which would allow precision timing with  more than 2 concurrent timers running independently to produce high frequency output signal?

            Sam





            On Wed, May 21, 2014 at 3:09 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
             

            Sam,


            Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

            I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


            They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

            If you are interested, there's much more from other skilled engineers here. 

            =====

            There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


            Jong




            On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

            Sam,


            This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

            If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

            =====

            Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

            So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


            Jong 

            On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

            Hi

            I've been thinking about this for a while and would appreciate some light.
            Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
            What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

            Thank you



          • Jong Kung
            Sam, Before I go into this : what is your electronics skill level? You can read circuits? You can wire / build circuits? You can design circuits ? You have /
            Message 5 of 20 , May 21, 2014
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              Sam,


              Before I go into this : what is your electronics skill level?

              You can read circuits?

              You can wire / build circuits?

              You can design circuits ?

              You have / don't have oscilloscope ?

              Etc.


              Jong 

              On May 20, 2014, at 8:19 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

              Jong; Thank you for your generous help.

              I would rather have a ready sine wave generator. Would DDS with a micro controller allow me to have a sine wave with increasing or decreasing amplitude? i.e. increase in each signal for the first x signals or period then stay fixed at a predetermined amplitude then repeat?

              Would you kindly recommend a Microchip brand uC which would allow precision timing with  more than 2 concurrent timers running independently to produce high frequency output signal?

              Sam





              On Wed, May 21, 2014 at 3:09 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
               

              Sam,


              Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

              I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


              They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

              If you are interested, there's much more from other skilled engineers here. 

              =====

              There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


              Jong




              On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

              Sam,


              This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

              If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

              =====

              Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

              So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


              Jong 

              On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

              Hi

              I've been thinking about this for a while and would appreciate some light.
              Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
              What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

              Thank you



            • alienrelics
              Frequency range? Power? How much distortion is allowable? Saying that you need a sine wave from a battery is like saying you need an engine that runs on fuel.
              Message 6 of 20 , May 21, 2014
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                Frequency range? Power? How much distortion is allowable? Saying that you need a sine wave from a battery is like saying you need an engine that runs on fuel. To power a model airplane? A generator? Lawnmower? Bus? Racecar? Ocean liner?

                If you want a ready source of sine waves, easiest way is to buy a signal generator.

                You can't just buy a DDS chip and build a sine wave generator. It is a chip that requires control signals from a computer or from a purpose built microcontroller control box, and then filtering and amplification of the output.

                Steve Greenfield AE7HD
              • Jong Kung
                Assuming the freq needed is audible range, one cheap method is use recorded sine wave out of some sort of sound player (cd player, mp3, etc). This will be
                Message 7 of 20 , May 21, 2014
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                  Assuming the freq needed is audible range, one cheap method is use recorded sine wave out of some sort of sound player (cd player, mp3, etc). This will be cheaper than buying a sine wave generator for just very limited freq or limited use.

                  ===

                  If you are an experimenter / getting into electronics, then I would also recommend getting a real lab sine wave generator. Many people here has one. There's nothing like pulling out your home made test equipment for designing / debugging your new circuit, only to find your source of your problem was the home made test equipment (ex: home made sig gen).

                  Of course that does not mean I am (or others are) deterring you from building one as learning experiment. That's why we are all here. We are just trying to help you solve your problem - and that could be buying a solution if you don't want to build one.


                  Jong





                  On May 21, 2014, at 2:45 AM, "alienrelics@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                  > If you want a ready source of sine waves, easiest way is to buy a signal generator
                • Sam Jesse
                  You can read circuits? Yes. You can wire / build circuits? Yes. You can design circuits ? To a level. You have / don t have oscilloscope ? I do. On Wed, May
                  Message 8 of 20 , May 21, 2014
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                    You can read circuits?
                    Yes.

                    You can wire / build circuits?
                    Yes.

                    You can design circuits ?
                    To a level.

                    You have / don't have oscilloscope ?
                    I do.



                    On Wed, May 21, 2014 at 10:39 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
                     

                    Sam,


                    Before I go into this : what is your electronics skill level?

                    You can read circuits?

                    You can wire / build circuits?

                    You can design circuits ?

                    You have / don't have oscilloscope ?

                    Etc.


                    Jong 

                    On May 20, 2014, at 8:19 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                    Jong; Thank you for your generous help.

                    I would rather have a ready sine wave generator. Would DDS with a micro controller allow me to have a sine wave with increasing or decreasing amplitude? i.e. increase in each signal for the first x signals or period then stay fixed at a predetermined amplitude then repeat?

                    Would you kindly recommend a Microchip brand uC which would allow precision timing with  more than 2 concurrent timers running independently to produce high frequency output signal?

                    Sam





                    On Wed, May 21, 2014 at 3:09 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
                     

                    Sam,


                    Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

                    I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


                    They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

                    If you are interested, there's much more from other skilled engineers here. 

                    =====

                    There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


                    Jong




                    On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                    Sam,


                    This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

                    If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

                    =====

                    Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

                    So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


                    Jong 

                    On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                    Hi

                    I've been thinking about this for a while and would appreciate some light.
                    Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
                    What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

                    Thank you




                  • rtstofer
                    Look at the AD9837 datasheet and see if it will do most of the work. There are similar AD devices with somewhat different capabilities. Amplification would
                    Message 9 of 20 , May 21, 2014
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                      Look at the AD9837 datasheet and see if it will do most of the work.  There are similar AD devices with somewhat different capabilities.  Amplification would be done elsewhere.  You could generate a zero crossing interrupt from the output signal and use that interrupt to change the amplification.

                       

                      AD9837 datasheet and product info | Low Power, 8.5 mW, 2.3 V to 5.5 V, Programmable Waveform Generator | Direct Digital Synthesis (DDS) & Modulators | Analog Devices

                       

                      The part is available at Digikey for about $5

                       

                      From the link above, there are other documents worth reading.

                       

                      Richard

                       

                       

                    • basicpoke
                      Go to Microchip s 8-bit microcontroller parametric search: http://www.microchip.com/ParamChartSearch/Chart.aspx?branchID=1012
                      Message 10 of 20 , May 21, 2014
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                        Go to Microchip's 8-bit microcontroller parametric search:

                        Go over to "Max 16-Bit Digital Timers" and choose '2'.

                        I would get one with plenty of Program Memory Size (flash) and RAM.  That leaves you with 4 choices.  I think a 28-pin will be easier to handle than a 40-pin, so that leaves PIC18F25J10, PIC18F45K50.  These will set you back either $1.27 or $1.99.  I would go with the latter because of more RAM.  They used to hand out free samples but don't know if they are doing it anymore.
                        Ron

                      • Jong Kung
                        One more possible option for microcontroller choice : avr butterfly. It comes with an LCD display, joy stick input, sound out, fairly large memory, etc.. So
                        Message 11 of 20 , May 21, 2014
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                          One more possible option for microcontroller choice : avr butterfly. 

                          It comes with an LCD display, "joy stick" input, sound out, fairly large memory, etc.. So if everything else fits the bill (serial out, etc.) then the built in LCD display would be perfect for user interface / display of freq. 

                          Just thinking out loud - I have not played with avr butterfly yet in person. 


                          Jong 

                          P.s.  the sound out is NOT for high quality sine out. I believe it is just piezo sound out. I forget, it's been years since I checked out the avr butterfly specs 


                          On May 21, 2014, at 3:57 AM, "basicpoke@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                          Go to Microchip's 8-bit microcontroller parametric search:

                          Go over to "Max 16-Bit Digital Timers" and choose '2'.

                          I would get one with plenty of Program Memory Size (flash) and RAM.  That leaves you with 4 choices.  I think a 28-pin will be easier to handle than a 40-pin, so that leaves PIC18F25J10, PIC18F45K50.  These will set you back either $1.27 or $1.99.  I would go with the latter because of more RAM.  They used to hand out free samples but don't know if they are doing it anymore.
                          Ron

                        • Jong Kung
                          Some micros need a programmer device. Others don t. Some can be programmed using the USB connector directly. Some need a USB to serial converter (which can be
                          Message 12 of 20 , May 21, 2014
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                            Some micros need a programmer device. Others don't. Some can be programmed using the USB connector directly. Some need a USB to serial converter (which can be almost as expensive as some low end programmers). During the days when every laptop had a serial port, this was the cheap option (program using the serial port) but not so much now. 

                            Sam : do you have digital / programming experience ??  


                            Jong 

                            On May 21, 2014, at 3:57 AM, "basicpoke@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                            Go to Microchip's 8-bit microcontroller parametric search:

                            Go over to "Max 16-Bit Digital Timers" and choose '2'.

                            I would get one with plenty of Program Memory Size (flash) and RAM.  That leaves you with 4 choices.  I think a 28-pin will be easier to handle than a 40-pin, so that leaves PIC18F25J10, PIC18F45K50.  These will set you back either $1.27 or $1.99.  I would go with the latter because of more RAM.  They used to hand out free samples but don't know if they are doing it anymore.
                            Ron

                          • Sam Jesse
                            I can program in some high level language. The signals will be used to analyze how some car devices respond to certain signals input to car computers. The need
                            Message 13 of 20 , May 21, 2014
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                              I can program in some high level language.
                              The signals will be used to analyze how some car devices respond to certain signals input to car computers.
                              The need might change later to used it for other home made projects.

                              Thank you all for your help and suggestions.


                               


                              On Thu, May 22, 2014 at 12:14 AM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
                               



                              Some micros need a programmer device. Others don't. Some can be programmed using the USB connector directly. Some need a USB to serial converter (which can be almost as expensive as some low end programmers). During the days when every laptop had a serial port, this was the cheap option (program using the serial port) but not so much now. 

                              Sam : do you have digital / programming experience ??  


                              Jong 

                              On May 21, 2014, at 3:57 AM, "basicpoke@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                              Go to Microchip's 8-bit microcontroller parametric search:

                              Go over to "Max 16-Bit Digital Timers" and choose '2'.

                              I would get one with plenty of Program Memory Size (flash) and RAM.  That leaves you with 4 choices.  I think a 28-pin will be easier to handle than a 40-pin, so that leaves PIC18F25J10, PIC18F45K50.  These will set you back either $1.27 or $1.99.  I would go with the latter because of more RAM.  They used to hand out free samples but don't know if they are doing it anymore.
                              Ron


                            • epa_iii
                              Just buy a digital chip. It is not that simple. Any method that you use to generate a pure sine wave is going to have it s limitations. That includes digital
                              Message 14 of 20 , May 21, 2014
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                                Just buy a digital chip. It is not that simple. Any method that you use to generate a "pure" sine wave is going to have it's limitations. That includes digital methods as well as analog. If you don't believe me, just look at the specs for commercial generators. Weather they use digital or analog generation techniques, they will all contain some distortion from a "pure" sine wave. Analog circuits will have more analog like distortion while digital circuits will have more digital like noise or distortion. The real question is how low that distortion is: it is impossible to completely eliminate it. But the circuits/generators ALL have their problems and some of them can be quite expensive.

                                And your application may be more tolerant of one or another type of distortion. That also should be considered. And, of course, there is always the cost factor. I don't know about yours, but my pockets are not infinitely deep.

                                What you really need to do first is decide just how "pure" you want it. In other words, you need to create a specification (spec.) for your application. What real world level should the non-sine wave distortion be reduced to? And then look for a method or circuit that can meet that spec.

                                As for the level control, a transformer is rarely used. Most circuits that generate waveforms will use a potentiometer for this. Many will use some form of automatic level control. But you need to have a circuit in mind first.

                                And a capacitor and inductor by themselves will not produce a sine wave or any other kind of AC. There is no such circuit. You are going to need some kind of active component like an amplifier, a motor/generator, or some other active mechanical, electric, or electronic mechanism.


                                ---In Electronics_101@yahoogroups.com, <jongkung01@...> wrote :

                                Sam,


                                Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

                                I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


                                They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

                                If you are interested, there's much more from other skilled engineers here. 

                                =====

                                There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


                                Jong




                                On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                Sam,


                                This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

                                If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

                                =====

                                Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

                                So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


                                Jong 

                                On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                Hi

                                I've been thinking about this for a while and would appreciate some light.
                                Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
                                What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

                                Thank you


                              • Jong Kung
                                Everything you wrote about analog and digital signal generator is all technically correct. But asking somebody who is asking us for help, to create specs is
                                Message 15 of 20 , May 21, 2014
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                                  Everything you wrote about analog and digital signal generator is all technically correct.  But asking somebody who is asking us for help, to create specs is bit much. 

                                  Lets not complicate the issue. The OP wants a signal somehow. We should try to point out various methods that might fit his needs without getting involved in too much details (percent accuracy, harmonics, etc.). 

                                  I come from software background. There are lots of people who argue this language is fast, that language is slow, etc...  But even the creator of the C language says to forget about run speed and DONT write code so difficult to read in search of fast running code.  Write the system and run it.  Find a any bottle necks, and optimize that section. Find next bottle neck once the first one is cleared - until the code runs in acceptable fashion. 

                                  I say the same for hardware design - especially for home / personal use.  Make the circuit and see how it runs.  Find and fault / short coming and fix that portion. 


                                  Jong 


                                  On May 21, 2014, at 8:47 AM, "palciatore@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                  Just buy a digital chip. It is not that simple. Any method that you use to generate a "pure" sine wave is going to have it's limitations. That includes digital methods as well as analog. If you don't believe me, just look at the specs for commercial generators. Weather they use digital or analog generation techniques, they will all contain some distortion from a "pure" sine wave. Analog circuits will have more analog like distortion while digital circuits will have more digital like noise or distortion. The real question is how low that distortion is: it is impossible to completely eliminate it. But the circuits/generators ALL have their problems and some of them can be quite expensive.

                                  And your application may be more tolerant of one or another type of distortion. That also should be considered. And, of course, there is always the cost factor. I don't know about yours, but my pockets are not infinitely deep.

                                  What you really need to do first is decide just how "pure" you want it. In other words, you need to create a specification (spec.) for your application. What real world level should the non-sine wave distortion be reduced to? And then look for a method or circuit that can meet that spec.

                                  As for the level control, a transformer is rarely used. Most circuits that generate waveforms will use a potentiometer for this. Many will use some form of automatic level control. But you need to have a circuit in mind first.

                                  And a capacitor and inductor by themselves will not produce a sine wave or any other kind of AC. There is no such circuit. You are going to need some kind of active component like an amplifier, a motor/generator, or some other active mechanical, electric, or electronic mechanism.


                                  ---In Electronics_101@yahoogroups.com, <jongkung01@...> wrote :

                                  Sam,


                                  Please be aware that many analog "sine wave" generator circuit (using discrete components) you might find online are NOT true sine wave - but close to sine at certain freq.  The same circuit you might find online might end up being triangle or even square of your vary the freq too much from the original design. 

                                  I'm not a very good circuit designer when it comes to analog sine wave generator / filter design.  So in the past I learned the easiest wave for beginner to get good sine wave is .... Buy a chip that generate sine wave using DDS (direct digital synthesis).  


                                  They talk about complete unit.  There are stand alone chips that need support input info and the chip will generate the requested sine wave. 

                                  If you are interested, there's much more from other skilled engineers here. 

                                  =====

                                  There are also purely analog chips that can also generate sine wave.  The DDS is the new and improved method. Many of these DDS chip require digital input parameter (requires some of microcontroller programming, user input, display, etc.) 


                                  Jong




                                  On May 20, 2014, at 6:55 PM, "Jong Kung jongkung01@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                  Sam,


                                  This depends on what you are trying to achieve.  Is it electronics you want to learn and you want to roll your own sine wave generator or is it that you just want sine wave - and don't care how you get it. 

                                  If you just want a sine wave and don't care if rolled your own circuit - you can feed sine wave from any device (PC + signal gen software, MP3 player / pre-recorded sound, etc) and feed that to a regular stereo amplifier.   The output will be any amplitude you want - just dial up the "volume". 

                                  =====

                                  Even if you want to design and build your own circuit, the idea is the same - design a sine wave gen subcircuit.  Design an amplifier subcircuit.  Test each section separately. And when both works then just connect them. 

                                  So do you want to roll your own, or is this some exercise to test some equipment and the method of signal generation is not the issue ????


                                  Jong 

                                  On May 20, 2014, at 2:16 PM, "Sam Jesse revrvr@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                  Hi

                                  I've been thinking about this for a while and would appreciate some light.
                                  Given a 12v battery. what is the process to create a "pure" sine wave of amplitude which is less than 12v, equal 12v or more than 12v?
                                  What comes to mind is use a capacitor and inductor in some arrangement to create the sine wave. and use some transformer to control the amplitude.

                                  Thank you


                                • rtstofer
                                  Jong, I don t see how we can propose solutions to a problem that lacks even the simplest specification. We don t even know the frequencies of interest: Hz,
                                  Message 16 of 20 , May 22, 2014
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                                    Jong, I don't see how we can propose solutions to a problem that lacks even the simplest specification.  We don't even know the frequencies of interest:  Hz, kHz, MHz, GHz?  Beats me...  'Pure': what's that mean, exactly?  No digital method is 'pure' without filtering and filters are usually frequency specific.  And how 'pure' does the signal need to be in the first place?  There may not even be a requirement unless it is for audio.  Is harmonic content even an issue?  It may be that the receiving device doesn't have enough bandwidth for harmonics to matter.  One thing is certain, the FFT of a digitally generated signal won't have a singularity at the desired frequency.  There will be harmonics.

                                     

                                    Then, the requirement expands from sine to arbitrary.  That's a pretty big leap because arbitrary waveforms will usually be table driven and the table can get quite large if the waveform doesn't have some kind of symmetry.  Not to mention the problem of defining 'pure' in the context of an arbitrary waveform.  For a sine wave, we only need table data for 90 degrees as symmetry will allow us to reuse those entries for other angles.  Not true when 'arbitrary' is part of the spec.

                                    I'm of the opinion that a lot more detail is required before it is even remotely possible to propose a solution.   Certainly, there are bits and pieces that might be used to make something up but, when the requirement moves toward 'arbitrary', the pieces get a little more complex.

                                     

                                    Richard

                                     

                                  • Jong Kung
                                    Richard, Yes, I stand corrected. We do need some more info (at least freq range). But the rest (sine wave purity, harmonics, etc) I have a feeling the OP
                                    Message 17 of 20 , May 22, 2014
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                                      Richard,


                                      Yes, I stand corrected.  We do need some more info (at least freq range). 

                                      But the rest (sine wave purity, harmonics, etc) I have a feeling the OP don't know, and he'll have to just go with whatever he can make / buy and give it a go - with the acknowledgment there's always a chance of failure due to lack of better specs at this stage. 

                                      It is my opinion to get as much spec / requirement as possible, but don't get stuck from lack of it. Jeri Elsworth has the opinion that to learn electronics, you need to fail and fail often


                                      By that she means don't be afraid to experiment and with experimentation comes failure. But there's lessons to be learned even in failure. If anything the lesson learned in failures are the lessons that's never forgotten. 

                                      That's all I meant.  Don't get mired in need for engineering specs that you would normally have in your engineering office / work environment. 


                                      Jong 



                                      On May 22, 2014, at 5:36 AM, "rstofer@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                      Jong, I don't see how we can propose solutions to a problem that lacks even the simplest specification.  We don't even know the frequencies of interest:  Hz, kHz, MHz, GHz?  Beats me...  'Pure': what's that mean, exactly?  No digital method is 'pure' without filtering and filters are usually frequency specific.  And how 'pure' does the signal need to be in the first place?  There may not even be a requirement unless it is for audio.  Is harmonic content even an issue?  It may be that the receiving device doesn't have enough bandwidth for harmonics to matter.  One thing is certain, the FFT of a digitally generated signal won't have a singularity at the desired frequency.  There will be harmonics.

                                       

                                      Then, the requirement expands from sine to arbitrary.  That's a pretty big leap because arbitrary waveforms will usually be table driven and the table can get quite large if the waveform doesn't have some kind of symmetry.  Not to mention the problem of defining 'pure' in the context of an arbitrary waveform.  For a sine wave, we only need table data for 90 degrees as symmetry will allow us to reuse those entries for other angles.  Not true when 'arbitrary' is part of the spec.

                                      I'm of the opinion that a lot more detail is required before it is even remotely possible to propose a solution.   Certainly, there are bits and pieces that might be used to make something up but, when the requirement moves toward 'arbitrary', the pieces get a little more complex.

                                       

                                      Richard

                                       

                                    • Nathan McCorkle
                                      Easiest solution: buy a signal generator. More detailed explanation of that: Embedded Artists LabTool; Digilent Analog Discovery Here are their schematics:
                                      Message 18 of 20 , May 22, 2014
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                                        Easiest solution: buy a signal generator.
                                        More detailed explanation of that: Embedded Artists LabTool; Digilent Analog Discovery

                                        Here are their schematics:

                                        the processor board, which is available for $20:

                                        you get the LabTool schematic when you buy the thing. At least it's software is completely open (on github).

                                        It's not too bad as far as getting things done, though I still haven't figured out how to get the USB running on a separate core (I wish it was as easy as arduino's serial.begin, that is something i plan to work on for this board)


                                        On Thu, May 22, 2014 at 2:49 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
                                         

                                        Richard,


                                        Yes, I stand corrected.  We do need some more info (at least freq range). 

                                        But the rest (sine wave purity, harmonics, etc) I have a feeling the OP don't know, and he'll have to just go with whatever he can make / buy and give it a go - with the acknowledgment there's always a chance of failure due to lack of better specs at this stage. 

                                        It is my opinion to get as much spec / requirement as possible, but don't get stuck from lack of it. Jeri Elsworth has the opinion that to learn electronics, you need to fail and fail often


                                        By that she means don't be afraid to experiment and with experimentation comes failure. But there's lessons to be learned even in failure. If anything the lesson learned in failures are the lessons that's never forgotten. 

                                        That's all I meant.  Don't get mired in need for engineering specs that you would normally have in your engineering office / work environment. 


                                        Jong 



                                        On May 22, 2014, at 5:36 AM, "rstofer@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                        Jong, I don't see how we can propose solutions to a problem that lacks even the simplest specification.  We don't even know the frequencies of interest:  Hz, kHz, MHz, GHz?  Beats me...  'Pure': what's that mean, exactly?  No digital method is 'pure' without filtering and filters are usually frequency specific.  And how 'pure' does the signal need to be in the first place?  There may not even be a requirement unless it is for audio.  Is harmonic content even an issue?  It may be that the receiving device doesn't have enough bandwidth for harmonics to matter.  One thing is certain, the FFT of a digitally generated signal won't have a singularity at the desired frequency.  There will be harmonics.

                                         

                                        Then, the requirement expands from sine to arbitrary.  That's a pretty big leap because arbitrary waveforms will usually be table driven and the table can get quite large if the waveform doesn't have some kind of symmetry.  Not to mention the problem of defining 'pure' in the context of an arbitrary waveform.  For a sine wave, we only need table data for 90 degrees as symmetry will allow us to reuse those entries for other angles.  Not true when 'arbitrary' is part of the spec.

                                        I'm of the opinion that a lot more detail is required before it is even remotely possible to propose a solution.   Certainly, there are bits and pieces that might be used to make something up but, when the requirement moves toward 'arbitrary', the pieces get a little more complex.

                                         

                                        Richard

                                         




                                        --
                                        -Nathan
                                      • rtstofer
                                        As to the Embedded Artists Lab Tool, that is an interesting setup. The price is certainly better than the Analog Discovery. OTOH, I didn t see a way to
                                        Message 19 of 20 , May 22, 2014
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                                          As to the Embedded Artists Lab Tool, that is an interesting setup.  The price is certainly better than the Analog Discovery.

                                           

                                          OTOH, I didn't see a way to produce arbitrary waveforms and I didn't see a way to offset the waveform above 0V.  There wasn't any discussion in the manual and there aren't any dialog boxes to accommodate this.

                                           

                                          I might just pick up one of the Lab Tools just to play with it.  I don't think it's going to dethrone my Analog Discovery but I do like to play with things.

                                           

                                          Richard


                                           

                                        • Howard Hansen
                                          Another approach for building a signal generator is the
                                          Message 20 of 20 , May 25, 2014
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                                            Another approach for building a signal generator is the
                                            <https://www.sparkfun.com/products/11420?utm_source=SparkFun+Customer+Newsletter&utm_campaign=63d7e9b972-May19-23&utm_medium=email&utm_term=0_fa5287abaf-63d7e9b972-60556193>

                                            For most applications you will need to use an opp-amp at the output to eliminate the off set in the output and to obtain a variable amplitude signal.

                                            The other Howard



                                            On 5/22/2014 6:55 PM, Nathan McCorkle nmz787@... [Electronics_101] wrote:
                                             
                                            Easiest solution: buy a signal generator.
                                            More detailed explanation of that: Embedded Artists LabTool; Digilent Analog Discovery

                                            Here are their schematics:

                                            the processor board, which is available for $20:

                                            you get the LabTool schematic when you buy the thing. At least it's software is completely open (on github).

                                            It's not too bad as far as getting things done, though I still haven't figured out how to get the USB running on a separate core (I wish it was as easy as arduino's serial.begin, that is something i plan to work on for this board)


                                            On Thu, May 22, 2014 at 2:49 PM, Jong Kung jongkung01@... [Electronics_101] <Electronics_101@yahoogroups.com> wrote:
                                             
                                            Richard,


                                            Yes, I stand corrected.  We do need some more info (at least freq range). 

                                            But the rest (sine wave purity, harmonics, etc) I have a feeling the OP don't know, and he'll have to just go with whatever he can make / buy and give it a go - with the acknowledgment there's always a chance of failure due to lack of better specs at this stage. 

                                            It is my opinion to get as much spec / requirement as possible, but don't get stuck from lack of it. Jeri Elsworth has the opinion that to learn electronics, you need to fail and fail often


                                            By that she means don't be afraid to experiment and with experimentation comes failure. But there's lessons to be learned even in failure. If anything the lesson learned in failures are the lessons that's never forgotten. 

                                            That's all I meant.  Don't get mired in need for engineering specs that you would normally have in your engineering office / work environment. 


                                            Jong 



                                            On May 22, 2014, at 5:36 AM, "rstofer@... [Electronics_101]" <Electronics_101@yahoogroups.com> wrote:

                                            Jong, I don't see how we can propose solutions to a problem that lacks even the simplest specification.  We don't even know the frequencies of interest:  Hz, kHz, MHz, GHz?  Beats me...  'Pure': what's that mean, exactly?  No digital method is 'pure' without filtering and filters are usually frequency specific.  And how 'pure' does the signal need to be in the first place?  There may not even be a requirement unless it is for audio.  Is harmonic content even an issue?  It may be that the receiving device doesn't have enough bandwidth for harmonics to matter.  One thing is certain, the FFT of a digitally generated signal won't have a singularity at the desired frequency.  There will be harmonics.

                                             

                                            Then, the requirement expands from sine to arbitrary.  That's a pretty big leap because arbitrary waveforms will usually be table driven and the table can get quite large if the waveform doesn't have some kind of symmetry.  Not to mention the problem of defining 'pure' in the context of an arbitrary waveform.  For a sine wave, we only need table data for 90 degrees as symmetry will allow us to reuse those entries for other angles.  Not true when 'arbitrary' is part of the spec.

                                            I'm of the opinion that a lot more detail is required before it is even remotely possible to propose a solution.   Certainly, there are bits and pieces that might be used to make something up but, when the requirement moves toward 'arbitrary', the pieces get a little more complex.

                                             

                                            Richard

                                             




                                            --
                                            -Nathan

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