Sloppy Schematic Questions

[bigkim100]

Ok, find attached an amazingly sloppy schematic that was sent to me.
My questions are:
1- What the hell are the 4 diodes doing??
2- Overall, its a pretty simple generator, but do you think it works, as it stands??

As per usual, thank you for any help, in advance

 

[bertus]

Hello,



Bertus

 

[Kiwi]

As Bertus explained above.

I would just put a diode inline in the positive supply line.
Current will only flow to the circuit if polarity is correct.
The diode will block current if polarity is wrong.
I have found this method more reliable than fitting crowbar diodes across the supply lines.

 

[Audioguru]

The diodes labelled D1 to D4 chop off the peaks of the triangle waveform creating a horrible looking "sinewave".
The lousy old LM324 opamp produces crossover distortion and noise. It has a very poor high frequency response.

 

[bigkim100]

thanks everyone

 

[davenn]

Hello,

View attachment 54031

Bertus

Maybe the wrong 4 diodes that the OP was referring to .... did you see the other 4 on the other side of the diagram ?

@bigkim100 ?? please clarify which ones you were referring to

 

[Harald Kapp]

Look up XR2206. This vintage IC is still available and generates squares, triangular waves and sinusoidal waveforms.
A complete circuit is presented e.g. here.

 

[bertus]

Hello,

The diodes D1 to D4 are there for a crude method of triangle to sine conversion.
It looks like the schematic is a direct copy of the wiki:
https://commons.wikimedia.org/wiki/File:Sine_sqare_triangle_generator_values.svg



bertus

 

[bertus]

Hello,

The diodes D1 to D4 are marked as 1N4004, wich are quite common.
There is a series from 1N4001 to 1N4007 depending on the reverse voltage.
Even a simple diode as the 1N4148 will do in that position.

Bertus

 

[bigkim100]

I dont know how, but when I looked that diode up, it came up as a 20v ZENER........ DUUUUUUUHHHHHHHHHH!

 

[bertus]

Hello,

Have a look at this query:
1N4004

Bertus

 

[bigkim100]

Hello,

Have a look at this query:
1N4004

Bertus

Yah, I now see it, but it confused me when the wrong semi came up on my search. Thank you for all your help.

 

[bertus]

Hello,

Yah, I now see it, but it confused me when the wrong semi came up on my search.

That is why I use Yahoo as search engine.
The advanced gives you more options:
https://search.yahoo.com/web/advanced?ei=UTF-8&fr=altavista&p=

Bertus