Hi,

I was wondering how to achieve the following triangle waveform:

[1]

I've seen some circuits based on the infamous NE555 (like the following: http://hades.mech.northwestern.edu/index.php/Circuit_diagram_for_wave_generator)

But this circuit based on NE555 is only able to give me a triangle waveform which starts (powered at 15 V) from 5 volt to 10 volt.

There is some other IC (maybe a function generator like ICL8038 or CD4049, or again some Opamps) which is able to generate a triangle waveform as shown in the picture [1] ?, Someone could suggest me some practical schematic?

Thank you.

 

Here, let me google that for you.

http://www.dogpile.com/search/images?fcoid=417&fcop=topnav&fpid=27&q=triangle+wave+generator&ql=

 

Hi, thank you for the reply.
I've seen most of these circuits, and most of them aren't able to cover my needs; I would prefer to receive some suggestion from someone which has built some similar circuit and which is surely functional

Thank you anyway.

 

You have not stated your needs except for, "adjustable frequency triangle wave". How am I supposed to guess which of hundreds of options will provide for your needs?

 

Hello,

Take the 555 oscillator with a rail-to-rail output op-amp and amplify it 3 times.

Bertus

 

You have not stated your needs except for, "adjustable frequency triangle wave". How am I supposed to guess which of hundreds of options will provide for your needs?

I'm sorry, maybe there is a lack of comprehension, since English is not my main language. My mainly needs is to find a schematic that would me assure an excursion of the triangle wave between 0 and 15 volt, and would be nice if I can adjust this waveform between 200 and 1200 hz.

Thank you.

 

I can't think of any circuit which would ramp from 0V to 15V if the supply were only 15V, so I'm guessing the waveform shown involved an opamp with a dual voltage supply, with +V >15V and -V < 0V.

 

Hello,

Take the 555 oscillator with a rail-to-rail output op-amp and amplify it 3 times.

Bertus

Thank you. Do you have some example? Anyway I have done some experiments using an NE555, but the resulting waveform wasn't exactly as i need:
http://s12.postimg.org/9cf2bc0n1/Onda_Trigger.jpg

 

Hello,

The wave form you show is not exactly linear.
The wave form of the 555 is also not linear.

Bertus

 

Thank you. Do you have some example? Anyway I have done some experiments using an NE555, but the resulting waveform wasn't exactly as i need:
http://s12.postimg.org/9cf2bc0n1/Onda_Trigger.jpg

Have you just shown us what you really need? That is not a triangle wave.

 

Have you just shown us what you really need? That is not a triangle wave.

In facts I need a triangle wave. This image http://s12.postimg.org/9cf2bc0n1/Onda_Trigger.jpg doesn't show what I need.

 

Hello,

Have a look at the following page:
http://www.maximintegrated.com/en/app-notes/index.mvp/id/4362

In the schematic the reference is 1.23 volts, wich is about 1/4 of the 5 Volt powersupply.
This will give the asymetric wave form.
If you want a symetric waveform the reference voltage needs to be 1/2 of the powersupply.

Bertus

 

Thank you Bertus, this schematic looks very interesting.

 

Try this:

 

Hi MikeML, this would be very good! Can you suggest me which kind of opamp could I use for this circuit?
Thank you very much.

 

Hi MikeML, this would be very good! Can you suggest me which kind of opamp could I use for this circuit?

I was afraid you would say that.
Here are three in DIP package that DigiKey has in stock. Learn to use their (or Mouser's) search tool if you dont like those....

 

I was afraid you would say that.
Here are three in DIP package that DigiKey has in stock. Learn to use their (or Mouser's) search tool if you dont like those....

Thank you, I really appreciate your suggestion and advices!

 

@MikeML : can you send me the .asc file?
Thank you.

 

Since I see the LT1498 in the DigiKey list, so I repeated the sim with that part. Note I can increase the gain of the buffer amp a bit, and get pretty close to the rails.

 

Since I see the LT1498 in the DigiKey list, so I repeated the sim with that part. Note I can increase the gain of the buffer amp a bit, and get pretty close to the rails.
View attachment 83392

Ok, I replicated the schematic using the LT1498, so i think that i will go with your schematic

Thank you again for your precious help!