Hi all... How to superimpose 2 wave forms? Please Help me

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Senthilkumar_rjpm

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Hi all...
some days before, For 1 of my project i needed wave form like this... (Below)



I can easily generate this wave form using this circuit (IC 4052) below...




And Now the same type of project i need this type of wave form... (below)



Now i didn't get any idea about to generate this wave form combination... i have a square wave with frequency of 100hz.. & Triangle wave with 3sec time delay... Now I dont know how to superimpose these 2 waveforms (Like square)?? I googled more but i didn't get any details related this...

(These types of waveform are using for treatment purpose in physiotherapy feild )

Can any one please help me how to superimpose square wave in to triangle wave...

Thanks in advance...
 

Superimpose isn't the correct term in my opinion (also in the first case). The problem is about modulating one waveform with another, respectively multiplying the waveforms. An analog multiplier can perfectly achieve this.

As a special case, multiplying with a square wave can also be achieved by an analog switch (as you did in the first case). On/off switching a triangular wave with a 100 Hz waveform would be a simple solution for the second problem and can avoid a multiplier, I think.
 

It wold be helpful if you could show a sketch depicting what the waveform should look like.
 

Thank you FvM....
I accept Superimpose may not be a correct technical term... thats some local language (here in my company) to identify this concept thats all...
How i switch (On/Off) triangular wave FvM... Is there any circuit?? can u pls give me more details or Links regarding this?

---------- Post added at 11:11 ---------- Previous post was at 11:06 ----------
Kral said:
It wold be helpful if you could show a sketch depicting what the waveform should look like.
Click to expand...

Thanks Mr.Kral....
Actually i provdivde details sketch in my question tag... (i dind't understand what sketch i show here) If you tell any particular sketch i must show it here...
 

Well, you need a multiplier circuit to do this. You can use any SPDT (Say 1P1G3157QDBVRQ1) and connect square wave to S and B1 with triangle to B2. You should be getting desired output.

Umesh.
 

How i switch (On/Off) triangular wave FvM... Is there any circuit??
Click to expand...
I was referring to your existing circuit and thought, the connection would be obvious:
Connect the triangle to pin 1 and the 100 Hz square wave to pin 10.
 

FvM said:
I was referring to your existing circuit and thought, the connection would be obvious:
Connect the triangle to pin 1 and the 100 Hz square wave to pin 10.
Click to expand...

Thank you FvM sir... But as per this logic we ll get triangle wave with 100hz interruption.. That means there is a gap for 100hz inbetween triangle wave... But here i need 100hz wave form (not gap) inside of triangle wave for my purpose... because, Furtherly i want to amplify this combination of wave forms... Anyhow you are triggering me to think some another angle I will think & come back to you... Mean time you also please tell me some more ideas... Thank you onece again...

---------- Post added at 16:11 ---------- Previous post was at 16:07 ----------
umesh49 said:
Well, you need a multiplier circuit to do this. You can use any SPDT (Say 1P1G3157QDBVRQ1) and connect square wave to S and B1 with triangle to B2. You should be getting desired output.

Umesh.
Click to expand...

Thanks mr umesh... That ic you suggested me is not available in our local market (chennai). & if i purchase some other cities or import means too much of cost.. pls refer me some another ic (DIP package is most welcome) if you know...
 

Hi Senthil,

According to me, what FvM suggested "Connect the triangle to pin 1 and the 100 Hz square wave to pin 10" should work for you.

The waveform that you want to achieve is not clearly mentioned. It can lead to 2 final waveforms. But both can be achieved by inserting/not inserting a NOT logic in the square wave path.
 

In fact, the 4052 is just acting as an analog switch. But you should draw the intended waveform exactly.
 

If you want a ramping 100 hz square wave, you will need an analog multiplier, not a digital circuit. Try the analog devices AD633, and input the ramp to x1 and the 100 hz signal to y1.

You will have to generate the ramp somewhere. You can have a somewhat non-linear ramp by just R-C filtering a 1 bit signal. If that is not linear enough for you, you can charge/discharge a capacitor with current sources made of transistors.
 

If you are searchnig in market, yuo can ask for a analog multiplxer or SPDT. You can order a sample from TI, they are really fast to deliver you the free sample.
 

FvM said:
In fact, the 4052 is just acting as an analog switch. But you should draw the intended waveform exactly.
Click to expand...

Yes sir... i agree that 4052 acting as an analog switch.. the wave form i drawn in my first post is exact sir...



---------- Post added at 14:04 ---------- Previous post was at 14:03 ----------
umesh49 said:
If you are searchnig in market, yuo can ask for a analog multiplxer or SPDT. You can order a sample from TI, they are really fast to deliver you the free sample.
Click to expand...

Thank you umesh.. let me try...
 

If you are searchnig in market, yuo can ask for a analog multiplxer or SPDT.
Click to expand...
^
You did realize, that the original post #1 is already using an analog multiplexer?
If you want a ramping 100 hz square wave, you will need an analog multiplier, not a digital circuit.
Click to expand...
If the square wave can be treated as a binary signal (0/1 or -1/+1), an analog switch will be sufficient as a multiplier, as already stated by several contributers.

the wave form i drawn in my first post is exact
Click to expand...
If so, it won't bring up these doubts...

P.S.: Do you intend this kind of waveform? It can be easily generated with an analog switch.

 
Last edited:

FvM said:
^

P.S.: Do you intend this kind of waveform? It can be easily generated with an analog switch.

Click to expand...

Yes Mr.FvM... i need this wave foem exactly... Is it comes in this (Your) Logic (Connect the triangle to pin 1 and the 100 Hz square wave to pin 10.)?
 

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