Search found 87 matches

by Viking
Tue Aug 26, 2008 2:42 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico, I will send you the design files to your email. I create most of the component outlines by hand with every design, the component library is not particularly useful and the symbol library is a bit on the 'chunky' side as well so will always use modified versions of the standard librar...
by Viking
Mon Aug 25, 2008 5:43 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico, I'm ready to send you the preliminary gerber file for the Display-receiver-PIC board. Can you reply to e-mail so that I can forward you the attachment. Regards Rob (added:- here is a jpg layout, showing pads tracks (red) and links (white). Note the slight discontinuity in the numberi...
by Viking
Sat Aug 23, 2008 10:27 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

One PIC per panel? Or one PIC per A6818? I thought one PIC per panel, driving however many A6818s as needed for a panel. (Like block diagram I put on page 7 except I put strobe from wrong source.) Are clock and strobe out of PIC converted to RS-485 then back to 0-5V logic level for each A6818? If l...
by Viking
Sat Aug 23, 2008 12:22 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello darker, OK on the 200seconds, the PIC will wait for the next 'break' however long that is. On the CAT-5 interconnection, I've made a mistake on the schematic, which I will need to correct. On the main board (receiver-PIC), there is an 8 way output to the next board in the chain via a simple li...
by Viking
Sat Aug 23, 2008 9:30 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Darker, Yes, there is one start bit followed by eighth data bits followed by two stop bits, as in the DMX specification. At the moment I can't think of a reason for using this arrangement, but it is quite common to have this arrangement, so there must be a good reason for it. The actual number...
by Viking
Fri Aug 22, 2008 10:28 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico, Thanks for the list of suppliers. I will use parts from these places when picking components for the PCB outlines. I should have a gerber file layout of a first draft of the receiver-PIC board by early next week. Will probably not be the final layout as there are probably still some ...
by Viking
Fri Aug 22, 2008 9:10 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico,
Latest version of Receiver-Display board. Still a work-in-progress but getting there.

Regards
Robert

Image
by Viking
Thu Aug 21, 2008 12:52 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico,
I've sent you a PM with my postal address.
Regards
Rob

ps what are your prefered component suppliers? This will help me lay out the boards with components that I know you can get your hands on.
by Viking
Wed Aug 20, 2008 3:40 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico
The PCB's look good, more than enough resolution for what we need I think.
One panel of 28 in comparison with average man (imike)!

Image
Which are your prefered component suppliers?
Regards
Rob
by Viking
Tue Aug 19, 2008 9:35 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico, By 'at the bottom of the screen' you mean at the base of the display? If so, yes I don't see why this should not work. Actually the power supplies could be quite simple, the AC supply is really just a transformer and the DC supply just a transformer with a rectifier/regulator built o...
by Viking
Tue Aug 19, 2008 3:57 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico, I think we will have to have a power supply per panel and suffer the extra expense of moisture proofing etc. I think we will make problems for ourselves if we try and power from a single source, both AC and DC, see attached. You end up with paralleled paths which carry both AC and DC...
by Viking
Mon Aug 18, 2008 3:41 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Dyarker The break time of 550uS is the minimum time, the PIC is looking for this as a signal to reset it’s channel counter. Then you get the 75uS, which again you can take as the minimum, but this is there really just as ‘padding’ to take the signal to logic 1, because the first channel ...
by Viking
Sun Aug 17, 2008 7:29 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico/Dyarker, No problem changing arrangement of pixel terminal blocks to remove the common terminals, the layouts were just an experiment to see how easy this was to lay out. When you talk about CNC milling machine, are you referring to a PCB router, that is a machine that ‘cuts’ out ...
by Viking
Fri Aug 15, 2008 11:44 pm
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Dyarker, just a quick answer to all your question, I hope. No, nothing has been 'designed' yet, layouts are just me playing around with different ways of placing the parts. I agree that probably trying to get all 200 pixel drivers on the single pcb will be difficult, so my idea is to have a re...
by Viking
Fri Aug 15, 2008 9:16 am
Forum: General Discussion
Topic: help on DC-AC inverter for Public art Project. Thks
Replies: 168
Views: 40694

Hello Federico,
Here is a more up-to-date schematic, and quick layout just to experiment with different layout schemes.

Image

Image
Regards
Rob