<snip>
would that be required in this project? Or something similar?

This project would not work for what you want to do.
Please keep your project in the thread that you started.

 

So I've been working in Eagle for some time on this, and I got a little bit blind. I settled for the fig 11.4 design.

Have I missed something?

Done some wrong connections?

The attachment is in Eagle format.

I can change the BC547 to 2N2222.

Edit: Forgot powerconnection and their capacitors....

 

Looks accurate to me, I had a little trouble fitting everything onto one sheet, but I managed. You really need to add those filter caps though. I'm thinking strongly about updating my image to have them in the article.

I am going to add a bit more to my schematic and make a PCB template. If you can publish yours in a format people can use, PDF or .gif. Gimp will take a X6 image and scale it accurately down to something that can be printed from a laser printer. Gerber is OK, but it means a hobbiest has to send the file off to be made. If I am wrong let me know, and I'll use the Gerber files if that is what you want.

 

Good to hear I didn't connect anything wrong.

I've added the filter caps.

Last night I had trouble placing everything on Eagle PCB. The board limitation stopped me, so I think I need to get the non-profit edition of Eagle. I would like to have all the LEDs in one single line. As per now, they are placed along 3 sides. Another solution would be to place the LEDs on another PCB, and connect the PCBs together with a flat ribbon cable. Need to check the price first.

I do not think I am able to place all traces on one side, so I can post both sides in PDF or .gif.

 

Jens,
I don't see connections to supply the board with Vcc and GND. The VCC and GND labels from the Supply-x.lbr don't establish connectors for wiring; they're basically just labels.

You might add some wirepads to make them non-specific to connectors.

 

Like this:

<snip>

I placed the schematic here. If I shrunk it, the quality went down...

The colors are Eagle standard, I guess. Red and green.

 

The writing on your schematic is too light to see. It is a light grey when it should be a dark black.

 

AG,
There doesn't seem to be an easy way to change the text color or attributes for the schematic portion of Eagle; not with v4.16r2 anyway.

However, there are a number of areas where wires overlap the NAME and VALUE fields; for example the base resistors. It would be a good idea to move the resistors close to the transistor bases so that there is more room for the text.

 

...
However, there are a number of areas where wires overlap the NAME and VALUE fields; for example the base resistors. It would be a good idea to move the resistors close to the transistor bases so that there is more room for the text.

Yes, I see. That would be a good idea.

 

So far, I got this:

As you can see, I'm not a PCB design guru. I think I will have just the LEDs on a different PCB, and a flat ribbon cable between the two PCBs.

 

Oops - it looks like you have placed all of the capacitors right near the power connector; they should be right next to the IC's!

The 555 timer needs a minimum of an 0.1uF and a 1uF cap across it's supply pins.

Also, sorry but I forgot to mention that your schematic omitted the diodes and jumper positions where people could select which LEDs they wished to light up. That'll be some ripping-up and re-routing for all that stuff.

 

Wookie, the switching time of a 555 is measured in nanoseconds (as is the shoot through), and given the 555 is feeding CMOS and other high impedance loads, there is no loading on the output. In this case I believe a 0.1µF next to the chip twill suffice.

 

Wookie, the switching time of a 555 is measured in nanoseconds (as is the shoot through), and given the 555 is feeding CMOS and other high impedance loads, there is no loading on the output. In this case I believe a 0.1µF next to the chip twill suffice.

Natrional Semi in their LM555 datasheet says, "Adequate power supply bypassing is necessary to protect associated circuitry. Minimum recommended is 0.1μF in parallel with 1μF electrolytic".

In their datasheet for their Cmos ICM7555, Intersil says that the shoot-though supply spike of an ordinary 555 is 400mA!

 

Oops - it looks like you have placed all of the capacitors right near the power connector; they should be right next to the IC's!

Argh... Remember now. Bill mentioned somewhere that the IC's had cap across their power connections...

The 555 timer needs a minimum of an 0.1uF and a 1uF cap across it's supply pins.

Thats an easy fix. Could I put this next to the power connector?

Also, sorry but I forgot to mention that your schematic omitted the diodes and jumper positions where people could select which LEDs they wished to light up. That'll be some ripping-up and re-routing for all that stuff.

I've been quite familiar with the rip-up button, and rip-up all.
Yes, I know. I meant to do that. I'm doing the fig 11.4.

Good thing the weekend is coming up.

 

Argh... Remember now. Bill mentioned somewhere that the IC's had cap across their power connections...

Yep, we have to practice what we preach. We still have newbies coming online that don't know about bypass capacitors, and how their absence will make for big problems. If we're posting projects that include board layouts, the caps have to be in place where they belong.

Thats an easy fix. Could I put this next to the power connector?

The 0.1uF cap should be as close as possible to the 555 timers' Vcc/GND pins. The 1uF cap can be a bit further away, but it should be pretty close by. Include a note that 1uF is the absolute minimum; it really should be larger.

I've been quite familiar with the rip-up button, and rip-up all.

I know your pain.

Yes, I know. I meant to do that. I'm doing the fig 11.4.

OK, good. Sorry I forgot to mention it earlier.

Good thing the weekend is coming up.

Absolutely!

 

Been trying to get this right, and I've settled for the Open End edition, due to limitation in both my PCB layout design knowledge, and the size in Eagle PCB. I'm going away from the fig 11.4...

Here you will find the edited schematic. I call it 25 open LED sheet 1. Some diodes and capacitors have been added.

This is the layout, so far...

Comments on the layout?

I will make a second schematic and PCB with the rest of the components and LEDs. Between them I will use ribbon cables.

 

Thank you guy. Aren't most ribbon connectors DIP (dual inline pins). I might be wrong, but it is what I am familiar with. Your board is a dual layer? If so, I would not have any feed throughs on the IC pins, as it would be very unsolderable with sockets. I'm thinking in terms of DIY PCB of course.

 

Thank you guy. Aren't most ribbon connectors DIP (dual inline pins).
I might be wrong, but it is what I am familiar with.

Yes, I guess they are. I'm using a single of row pins, and I'll try to solder the female part to the ribbon-cable.

Your board is a dual layer? If so, I would not have any feed throughs on the IC pins, as it would be very unsolderable with sockets. I'm thinking in terms of DIY PCB of course.

It's dual layer, and I'm re-routing all traces from the sockets, so the soldering job will be "do-able". In another project, I experimented with the feed throughs. It was hard and not very good looking.

For the other PCB, I have to move to QCAD for the PCB layout, since the Eagle limitations don't let me place all LEDs in a row. The row will be too long and go outside the board limits.

(Guess I'll by the non-profit license key next week)

 

Since you are further along than I am I'm going to bump over into another variation, I'll show it later. I had drawn the variation you were working on with express, see the attached file. I was able to fit the schematic on one sheet.

Unfortunately for me I am in between printers. My inkjet was a casualty of the rolling blackouts in the area. I need a Win98SE compatible, so I am going to take my time replacing it.

Side note of the difference between PCB Express and Eagle. Eagle is a pro package, and they cripple it because of this. Express wants you to use their service to make the PCB, and since they charge by the square inch there isn't the same size limitations. Express is also a lot easier to learn, although it is totally incompatible with Eagle. If I make this board it will be on one board, since Express doesn't have the artificial limitation you are fighting.

 

Side note of the difference between PCB Express and Eagle. Eagle is a pro package, and they cripple it because of this. Express wants you to use their service to make the PCB, and since they charge by the square inch there isn't the same size limitations. Express is also a lot easier to learn, although it is totally incompatible with Eagle. If I make this board it will be on one board, since Express doesn't have the artificial limitation you are fighting.

Yes, I am aware of that. I've checked around and the pricing for the Standard Edition is not too frightening. But, there are still some limitations. If I place all LED in a single row, the row will at minimum be 24 cm long. The standard edition has a 16 cm limitation... Guess I go for QCAD and the toner transfer method for this one.