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by woody1189 on Tue Aug 05, 2008 8:07 pm

whoops i picked the wrong numbers off one of the parts lists. i assumed those were 25 and 30 degree ir leds.
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by shadow on Sun Aug 10, 2008 11:48 pm

ok, so i'm trying to do a small project to make a board in eagle and get a successful prototype. The board is an EHP tv-b-gone, based off of oPossum's EHP, just i wanted it small as possible (no 10 pin header). Well, I quoted it at 4PCB, and got pretty bad prices for prototypes. Am i doing something wrong? Also, im leaving Monday for a week so ill read any help when i get back
the quote and the board:

Image

Image
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by The_Don125 on Mon Aug 11, 2008 12:13 am

Advanced Circuits (or any board manufacturer for that matter) will charge you an arm and a leg for a small production run (100 units or less). The best way to get a board is to find somebody who had a batch made, and ask them for one. Your best bet is something like Gold Phoenix, who for $90 will give you about 30-40 of these EHP sized boards. Alternatively, you can use BatchPCB and get a single board like this made for about $20.

Bottom line, professional PCBs are expensive in 1's and 2's.
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by shadow on Mon Aug 11, 2008 12:26 am

thx so much

i might go with batch or Gold Phoenix then

P.S. does the crcuit board look ok? (except the missing traces Between the + line and some IR LEDs) I got many ideas from oPossum to make this board
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by caitsith2 on Mon Aug 11, 2008 3:44 pm

shadow: before you get that pcb manufactured, put 20 mil ID vias on top of each and every one of those LED SMD pads. If you fail to do that, you will have some difficulties with actually mounting the IR LEDs.
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by shadow on Thu Aug 14, 2008 4:58 pm

ok, this is beginner, but it brings up too good of a point to miss. how exactly do i make a id via? is that different then a regular via? I am also not familiar with sizes. hw to i make it 20mil (is that millimeters? because that would be a BIG via)

Sorry for the begginer stuff, but all help is appreciated
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by The_Don125 on Thu Aug 14, 2008 5:03 pm

Not sure about the id via thing, but mil = thousanths of an inch.
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by caitsith2 on Sat Aug 16, 2008 3:05 am

id = inner diameter. That will be the size of the plated through hole to be made. This has to be big enough in order for the IR LED leads to go through, but not too big.
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by Probedude on Tue Aug 19, 2008 9:21 am

caitsith2 wrote:id = inner diameter. That will be the size of the plated through hole to be made. This has to be big enough in order for the IR LED leads to go through, but not too big.


I don't think 20 mil will be big enough. Need at least a 28 mil finished hole.

At first I thought you were saying a via is needed so that the bottom side trace would be connected to the upper pad. As the artwork is drawn, they're disconnected.

One would not have to put the LED's into holes. You could lay them on the board and 'surface mount' them, but you still would need the via to get the power from the bottomside trace to the top.
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by shadow on Tue Aug 19, 2008 12:17 pm

Ya, before i sent the board in, i put vias in (using sizes from other components holes). I dont even plan on mounting the LEDS on the board, just wires connecting them.

Thanks to alll who helped me through this, and especially oPossum who gave me an idea as to how the hell i was gonna layout the board. Oh i hope it works, and if it does i feel bad for best buy
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by woody1189 on Thu Aug 21, 2008 6:22 pm

i just put together a chip version tv b gone and im watching the currents through the leds and im seeing a range of 3-25ma during pulses...aren't they supposed to be much higher?
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by woody1189 on Thu Aug 21, 2008 9:15 pm

just experimenting with the chip design some more...i noticed some problems with 4 leds off of 3 fresh alkalines in that the codes wouldn't cycle. i dont think the alkalines can supply enough current for 4 emitters but when you use just 2 leds it blasts em. lost 3 tsal6100s in the process :(
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by Probedude on Thu Aug 21, 2008 10:56 pm

woody1189 wrote:i just put together a chip version tv b gone and im watching the currents through the leds and im seeing a range of 3-25ma during pulses...aren't they supposed to be much higher?


How are you looking at the current pulses?
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by woody1189 on Fri Aug 22, 2008 12:02 am

i was using a multimeter but then i realized that those readings were most likely wrong. i was hoping to at least see some spikes above 100ma but all i got were low readings. i'm gonna test it on a scope once i go back to school next week.
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by Probedude on Fri Aug 22, 2008 12:18 am

woody1189 wrote:i was using a multimeter but then i realized that those readings were most likely wrong. i was hoping to at least see some spikes above 100ma but all i got were low readings. i'm gonna test it on a scope once i go back to school next week.


Definitely need a scope, the pulses are really short.
Somewhere (I think in this thread) I posted scope traces of the V1 and V1.1 'like' TV-B-Gone which will give you an idea of the current being pumped into the LED's from those circuits.

FWIW, I just finished a small, single sided 8 LED EHP version TV-B-gone. I'm using a 1 cell lithium polymer battery. Pretty small little package, but I can't find my TSAL6100's to stuff the board with :(
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