SparkFun Forums

[unebonnevie]

Ok,

Very newbie...Now that I have gone through 4 Sparkfun tutorials, and things look great with the breadboard. I am ready to make a 5V/3.3.V power supply on a proto/perf board. This means that I would be soldering stuff.

In the power supply circuit (from Sparkfun's tutorial), the power source is basically a 9V battery, which is connected to a variable voltage regulatr, the LM317, which has a ground pin.

So, other components will also connected to GND.

Here goes my silly question:

Is there any tip (so that my perf board soldering won't be too messy on the perf board) when components are connected to GND? I figure that all the ground connections from all the components would connect to the GND pin of the voltage regulator, the LM317, no?

Thanks.

[theatrus]

You'll quickly find it hard to stuff a large number of wires to a single ground pin. While doing star grounding (which is bringing a single line from every point to a single source) can be very advantageous, your circuits probably won't be sensitive enough to require that.

Depending on your layout, you can emulate what a breadboard does and make a connected strip of pads all be ground. Just blob solder bridges on the board. You can even make a crude trace which changes direction like this.

[unebonnevie]

I googled 'star grounding' and found some more explanation, even intro to bus grounding, but unfortunately, couldn't www page that has pictures for newbies or even a tutorial.

Any site you know? Thx

[FartingMonkey92]

http://www.aikenamps.com/StarGround.html - No pictures, but a good explanation on why it is used...

'Star Grounding' is only of serious importance with audio circuits so you don't create ground loops (not that
grounding in digital circuits is unimportant ). As for planning and stuff, i've used this app a while ago, it
was handy for planning quick proto's...

[theatrus]

Thats a nice little app there...

Are you using a proto board with only annular rings and no connecting traces (aka, it has copper rings around each hole but no copper connecting the various holes together)?

[unebonnevie]

Yes, I use proto boards with only annular rings.

[signal7]

I just finished making one of those. I used the same perfboard as you do - mine only has annular rings on one side. What I did was I sortof threaded the left-over lead lengths on the capacitors so that they lay along a string of holes. When I want to make a connection to either side of the capacitor, I simply route a lead through one of the holes. Solder the capacitor lead to the annular ring and the wire coming through the hole. It's a lot less messy than trying to get everything to come to one point. Also, on the LM317 circuit, the capacitors are ideally placed for this kind of connection.

I still wound up with one or two jumpers, though. I'm happy with the results I have. The next time I'm submitting a board for BatchPCB or Gold Phoenix, I'm probably going to make it into a real PCB because it would take up a lot less space that way.

[thor]

I'm assuming that you are using a proto-board that has just holes and copper pads, no connected strips.

Honestly, the very best thing to do with a proto-board is make the component layout look like the circuit diagram. I know that doesn't specifically address your question about the ground, but when your circuits get more complicated it will really make trouble shooting easier. Don't necessarily optimize for space, make sure everything is clearly placed.

As for the grounds, you are connecting the voltage regulator, 2 caps and an output. I would solder in a pin header for the 5v out and the GND out to make connections simpler to a breadboard, or if you have some other connector you prefer, use that.

I would pass the cap leads through the board, solder them, but don't clip the excess, use that bare wire from each cap to come together at the voltage regulator pin and solder them all together. This is pretty simple, you don't connect them in a star configuration where they don't all fit in a hole, and it looks like the ckt.

Good luck, and post pix.