PCBs vs. perfboard / General Science and Electronics / Forums

Forums

4hv.org :: Forums :: General Science and Electronics

« Previous topic | Next topic »

PCBs vs. perfboard

previous 1 2 3 next

Move Thread

LAN_403

Part Scavenger

Wed Feb 15 2006, 02:51AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

I actually thought about bending them over, just thought that might add confusion. I never thought to use that to my advantage though. That's pretty ingenious!

EEYORE

Wed Feb 15 2006, 06:31AM

Registered Member #99 Joined: Thu Feb 09 2006, 06:10PM
Location: florida, usa
Posts: 637

Why not line them up so that inputs are inline and outputs are inline?Outputs are then much closer together, as well as the inputs....

Matt

ragnar

Wed Feb 15 2006, 06:53AM

Registered Member #63 Joined: Thu Feb 09 2006, 06:18AM
Location:
Posts: 1425

mattrg2 wrote ...

Why not line them up so that inputs are inline and outputs are inline?Outputs are then much closer together, as well as the inputs....

Matt

It's all very easy to say "Why not...." however there are several problems:

the particular chip I was working with has POSITIVE at the TOP, and OUTPUT on the LEFT.
the UCC gatedrivers, however, have positive at the top, but their OUTPUTS to the RIGHT. So there's no logical way (on a single-sided board) to lay things in line, outputs from chips into inputs of the next, etc etc etc.

If you put them inline, then you have to cross the power lines over the lower-impedance lines (e.g. the signal/input, pin2), and also the enable pin. If you put them back to back, then somehow you have to get the power diagonally over to the other end of the other chip, thus again crossing jumpy powerlines over inputs and outputs.

My aim was to keep the high-frequency leads (pin2 etc) as short as humanly possible, not have ANY links, have the lower-impedance capacitors as near to the rails as humanly possible, and not have any inputs crossing outputs, or power crossing inputs or outputs.

It's not so easy when you actually start drawing things and realising where you need space etc. I guess I've settled on my chip-mangling methodology... which gives the circuit a nice sense of symmetry too... its quite pretty I think.

I've found this is very compact on the board, and it confuses people to boot!

Dr. Shark

Wed Feb 15 2006, 12:26PM

Registered Member #75 Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711

Wow, thanks for all the input, guys!
I was not considering the "hand-drawing" method at all, but it seems to have certain advantages if you just want to lash up something quickly, like I usually do. I think I'll just get a few boards and etchant, and try it out. I dont really know what paint pens are, so I'll try with permanent markers. If it does not work, I'll try the Gootee (sounds like Goatse to me, but dont google that!) method next.
I thought this whole PCB-making thing would be much more complicated. A few years ago when I did it in a uni lab we had all these UV exposure units, etching tanks etc., I didn't know it could be done so simply.

Part Scavenger

Wed Feb 15 2006, 05:57PM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

Goatee is better than paint pens, I think personally. But you can get paint pens at hobby lobby or somewhere similar. They're like giant ball point pens with paint and a "shake marble" in them. They'll know what they are there.

Marko

Wed Feb 15 2006, 08:52PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

I actually mastered (

) using protoboards, because of bad luck with pcbs, they are simply never perfect and always have (relatively) large holes or ''hills'' in photosensitive varnish.

I made some PCBs using 'letraset' (I dont know how do you call it) it takes lots of patience, cannot be used for smd but result is great.

Here is how I keep protoboards with lowest stays possible, this is a field strength meter:

Bjørn

Wed Feb 15 2006, 10:57PM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

The method used is mostly a matter of personal choice. Depending on how you work and what result you need one method may be much more efficient than the other.

This I/O podule for an Acorn Archimedes was made with the databook in one hand and the soldering iron in the other. Some people may find it ugly but it works perfectly and took very little time to make. It also has endless possibilities for changes and further development.

Alex

Wed Feb 15 2006, 11:07PM

Geometrically Frustrated
Registered Member #6 Joined: Thu Feb 02 2006, 04:18AM
Location: Bowdoin, Maine
Posts: 373

The toner transfer method has been very popular recently, and the results are high quality and reproducible.

[edit] I see that this has already been mentioned, but no link was posted... Also, it's "Gootee," not "Goatee."

HV Enthusiast

Wed Feb 15 2006, 11:39PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

Don't forget there is wire wrap out there too. This can be especially effective especially when you need to make continual changes.

The entire signal processing cabinets used in the radar systems we build for the US Navy are ALL wirewrap!!!

Part Scavenger

Thu Feb 16 2006, 12:55AM

Registered Member #79 Joined: Thu Feb 09 2006, 11:35AM
Location: Arkansas
Posts: 673

I see that this has already been mentioned, but no link was posted... Also, it's "Gootee," not "Goatee."

Whoops! Brainfart. Thanks for catching that Alex.

previous 1 2 3 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob