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Fishfeeding contraption

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LAN_403

Tesladownunder

Wed Jul 25 2007, 01:06PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

Your ugly pre-prototypes are my glorious finished product!

Here is my maglev driver still running perfectly after 2 years of daily museum use.

TDU

1185368808 10 FT28856 Maglevpcbtop Small

1185368808 10 FT28856 Maglevpcbbottom Small

ragnar

Wed Jul 25 2007, 03:44PM

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

What's the secret to getting those IC sockets to stay in with no copper to solder to?

Tesla_Cubed

Wed Jul 25 2007, 04:22PM

Registered Member #594 Joined: Tue Mar 20 2007, 04:02PM
Location: Joplin Mo USA
Posts: 6

Fold out the outer most 4 pins after sticking it in the proto board.That holds it still to solder the other stuff to it.

thedatastream

Wed Jul 25 2007, 07:36PM

Registered Member #505 Joined: Sun Nov 19 2006, 06:42PM
Location: Yorkshire!
Posts: 329

1181134250 505 FT24811 Controller Lid Underside Sm

1181134269 505 FT24811 Controller Main Box Sm

One of my more comapct layouts, done on "spot board" where each hole just has an individual round pad on the underside. Route the power supply traces first with tinned copper wire and plenty of decoupling. Signal traces routed with wirewrap or with more tinned copper wire with coplanar ground for critical traces.

Plug in breadboard and stripboard are both the work of Lucifer and should be punished >8-(

I've "dead bugged" stuff before for a 2:1 VGA switch using SMT amplifiers and the ground plane works a treat. Having the power plane on the other side of the board works a treat too!

Marko

Thu Jul 26 2007, 09:42PM

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

Hey, some nice threads have arisen since I wasn't here.

Blackplasma: I see you also like those boxes

Where did you find them in Australia? I thought they are produce in Germany or something.

I built a prototype hard-firing dimmer in same box but used a lot of SMD and airwires.
All I think you should have done is to arrange those resistors more neatly, I mean, allways in same footprint and use airwires between them.

Double-sided board is also nice, it allows use of SMT, conductors top side as well as easier airwiring.

I also do all my prototyping on breadboards, despite all their flaws, as perforated boards are too expensive to be wasted like that. In most cases, I know that ''prototype'' I build on perfboard WILL be the only and finished product, I do it with maximum care about everything.

ON bigger boards I can often completely avoid use of airwires by using only short pieces of wire between connection points. This is very time consuming, though.

Final neatness will always be proportional to speed of development and you can do little about it.

It may even be good to simply etch a iron-on board (wich is very easy once you master it), populate, correct bugs and etch a new debugged board rather than mess with all the prototypes.

Marko

ragnar

Fri Jul 27 2007, 11:29PM

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

Quick reply with pics because I have to run:

The one thing I will say is that lining up holes in the lids for drilling is HARD. :P

...

Mon Aug 06 2007, 06:13AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

I finally got to take pics of a piece of my work at Ortel (this was a part of a display panel for the gas cabinets with the Phosphine/Arsine gases)

ragnar

Mon Aug 06 2007, 06:50AM

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

Cool protoboard. What does it do, and are those diodes for some mickey-mouse logic AND gates? Is it so you can reverse them to get different ANDs? :P

...

Mon Aug 06 2007, 03:38PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

You see, there are 4 tanks that have a few pounds of liquid AsH3 and PH3 (enough to kill a small city), so we are somewhat concerend when the alarm triggers. So instead of just wiring those outputs to 4 lights, it was decided that we should make the light flash (especially since there is another row of red lights directly above them that are always on indicating that some of the tanks are turned off). But why stop there? Then we added on a buzzer than goes off when any of the tanks alarm, and a latch so that even if you aren't arround when the alarm goes off you will still know that something bad happened. And for sanity sake, we also added a button that lets you scilence the buzzer.

So to answer your question, the diodes form a OR gate of sorts. The original plan (drawn by last years intern who had a masters in EE) had the 4 alarm channels wired into a relay which was wired to latch on. Of course any monkey with a soldering iron would have soon realised that if you actually built that you would short all of the channels together when any of the tanks alarm... So I added in a few diodes to isolate the channels from eachother.

And yes, if you pull any of the top 4 diodes, you can remove a channels ability to trigger the alarm, and if you pull the bottom diode the alarm no longer latches on (but no one else knows that

)

Experimentonomen

Mon Aug 06 2007, 09:19PM

Registered Member #941 Joined: Sun Aug 05 2007, 10:09AM
Location: in a swedish junk pile
Posts: 497

What is donutboard, blackplasma ?

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