[Suggestions] What is wrong with this schematic?

[WaRc3L]

Hello everybody,

I am newbie into design of PCB and I need your help for a suggestions about this schematic. It's a simple triangular-wave generator with a potentiometer to modify the frequency of the signal.

Can I do it better?, what's seen in the schematic that "cries" your eyes?

Thanks for all, and sorry for my english.

pD: Do you know any tutorials or suggestions on Internet to pass the schematic into a board-design PCB?, I have seen the BenHeckShow tutorial and Jeremy Blunm on youtube, but it's not enough for me...

Regards,

Marcel

[McBryce]

The first thing that's obvious is that it's extremely difficult to read at a glance. did you make the 741 symbol yourself? Eagle already has a 741 symbol in it's library. The circuit is much easier to understand if you use the standard op-amp type symbol (see attachment).

McBryce.

[WaRc3L]

The first thing that's obvious is that it's extremely difficult to read at a glance. did you make the 741 symbol yourself? Eagle already has a 741 symbol in it's library. The circuit is much easier to understand if you use the standard op-amp type symbol (see attachment).

McBryce.

Yeah, it's obvious  . I found the symbol into ST Microelectronics, I don't remember why.  Thanks!!!.

Any other suggestions?

Regards,

Marcel

[McBryce]

The green dots on the component pins aren't necessary unless there is more than one wire (net) going to the pin. The dots are usually just for joining two wires together. A single wire going to a pin is automatically connected. It's not wrong how you have it, just more work than is needed.

McBryce.

[WaRc3L]

Perfect!!!, thanks a lot

Regards,

Marcel

[Neilm]

A personal preference of mine - if two wires are crossing and are connected, I don't have them in the form of a cross as you have for your TRI port, but will offset them to form 2 T intersections. This means that I can tell at a glance that when one wire is going over another they are not connected rather than having to look. . It also means that if I see  dot in this situation, I know to have a good look to check they should be connected.

[codeboy2k]

A personal preference of mine - if two wires are crossing and are connected, I don't have them in the form of a cross as you have for your TRI port, but will offset them to form 2 T intersections. This means that I can tell at a glance that when one wire is going over another they are not connected rather than having to look. . It also means that if I see  dot in this situation, I know to have a good look to check they should be connected.

Yes, this is very important, and something I always do too.  Crossed wires never connect, and connections are only made using 'T' junctions, never '+' like that.
This way you always know when something is or is not connected -->>  "T" junctions ALWAYS connect.  "+" junctions NEVER connect.

[c4757p]

Multiple standards require this, and for a reason.

[WaRc3L]

A personal preference of mine - if two wires are crossing and are connected, I don't have them in the form of a cross as you have for your TRI port, but will offset them to form 2 T intersections. This means that I can tell at a glance that when one wire is going over another they are not connected rather than having to look. . It also means that if I see  dot in this situation, I know to have a good look to check they should be connected.

Wow, thanks Neilm and codeboy2k!!.

With all about your suggestions, I made this schematic. Is it better?.

And, to reuse the post, I designed this PCB board with the Autorouter of Eagle. What do you think?, Is it really finished?.

I remember that I am newbie with the designs of PCB...

Regards,

Marcel

[milow]

The triangle wave is at the output of U1. Right now, you would get a linear combination of the triangle wave and the rectangular wave.

[WaRc3L]

The triangle wave is at the output of U1. Right now, you would get a linear combination of the triangle wave and the rectangular wave.

Thanks for the annotation!

[Zero999]

Do you want to vary the frequency of the triangle wave, without changing its amplitude? If so then you need to make R1 the potentiometer and leave R3 fixed.

The 741 is only suitable for low frequencies. You won't get a very good squarewave above a couple of kHz. I haven't done any calculations so don't know what frequency it'll oscillate at.

[Hideki]

I designed this PCB board with the Autorouter of Eagle. What do you think?, Is it really finished?.

No. While it is connected up according to the schematic, it does looks like what you get when you let a beginner use the autorouter. The only reason to use an autorouter if you're a beginner is to try it out and learn some of the possible ways that traces can be connected. Once you get better at figuring that out you should do it manually... every time, every single time, always. After you get really good at it (maybe some years later) you can consider looking at autorouters again.

The components are placed almost at random with large areas of unused space instead of grouping the components in any way. Strange connections all over the place. When you have that few components you really should try keeping all the connections on one side. Bottom if through hole and top if surface mounted. 2 layer prototype boards cost the same, so it's not that you HAVE to. It's just good style. Especially when you're learning how to do it.