## power and signal wires design between tow PCB borad

Started by in sci.electronics.design7 years ago 6 replies

Hi, I am freshman in electronics design. Recently, I was troubled by the power and signal design in PCB board. I hope someone can help me, thank...

Hi, I am freshman in electronics design. Recently, I was troubled by the power and signal design in PCB board. I hope someone can help me, thank you. I have two PCB board, PCB A and PCB B. There is information exchanging these two PCB ,but PCB A and PCB are powered by separated power(5V DC power). At first, I just connect the signal wires between PCB A and PCB B, then I find both PCB A and PCB ...

## PCB Copper Thickness Versus Rth - is this graph correct?

Started by in sci.electronics.design6 years ago 14 replies

Hi I have a PCB, 50mm x 50mm, and I need to optimize cooling of the PCB. A num= ber of dissipating components are spread out on the PCB to...

Hi I have a PCB, 50mm x 50mm, and I need to optimize cooling of the PCB. A num= ber of dissipating components are spread out on the PCB to produce an unifo= rm temperature across the PCB. Currently I am using 0.5 Oz PCB thickness, but it is possible to increase t= hat to 1 Oz. So I was looking for a graph of the thermal resistance on a certain area of= PCB versus the copper thickness...

## Creating a Schematic from a PCB - What tools are available.

Started by in sci.electronics.design7 years ago 6 replies

I have a desire to take a populated PCB, take a digital photo of the top and bottom, then import the images into a PCB layout tool. What would...

I have a desire to take a populated PCB, take a digital photo of the top and bottom, then import the images into a PCB layout tool. What would be ideal would be to lay components on top of the imported PCB image on a different layer, manually route these components (following the tracks from the image), then do a 'Forward Annotate' to create the schematic. I cannot seem to find a PCB layo...

## PCB high current bars

Started by in sci.electronics.design11 years ago 6 replies

Hi, Are these bars that are soldered onto PCB's to increase the current handling of the PCB stock...

Hi, Are these bars that are soldered onto PCB's to increase the current handling of the PCB stock items? http://rocketresearch.nekrom.com/new/PCB%20high%20current%20bars/PCB%20high%20current%20bars.jpg cheers, Jamie

## _Anyone using DesignSpark PCB

Started by in sci.electronics.design6 years ago 3 replies

Found Design Spark PCB program while looking at comments about Sprint PCB. No cost for commercial or hobby use. Sounds nice, but is...

Found Design Spark PCB program while looking at comments about Sprint PCB. No cost for commercial or hobby use. Sounds nice, but is it really? Dan

## Free/Open Source PCB autorouter in development; help wanted

Started by in sci.electronics.design8 years ago 34 replies

Hi, There are a few free/open source PCB autorouters available however using them has been quite difficult due to a lack of...

Hi, There are a few free/open source PCB autorouters available however using them has been quite difficult due to a lack of interchange standards. There are at least three available such as MUCS-PCB, gEDA PCB (includes autorouter), and the Topological Autorouter (experimental also part of gEDA PCB). The QAutorouter provides a solution of building the Specctra DSN import and SES export ...

## How do I set the pcb-lesstif's min-silk DRC parameter

Started by in sci.electronics.design4 years ago 1 reply

I got loads of errors for the 0805 smd resistors coz the silk lines are too thin. What I've tried: in .pcb/settings min-silk = 1.00 mil in...

I got loads of errors for the 0805 smd resistors coz the silk lines are too thin. What I've tried: in .pcb/settings min-silk = 1.00 mil in a local pcb.settings min-silk = 6.00 mil ..saved earlier, that line uncommented and changed to 6.00 mil from the 10.00 mil before... in a bash script: #modify to taste pcb-lesstif ./tmp_pwm_p.pcb --lib-newlib ./pkg:/usr/share/pcb/newlib:/usr...

## Plugs for bare PCB holes

Started by in sci.electronics.design1 year ago 18 replies

Many years ago I came across a connector that was a push-fit into a PCB and didn't require soldering. I'm not sure if these haven't gone out of...

Many years ago I came across a connector that was a push-fit into a PCB and didn't require soldering. I'm not sure if these haven't gone out of favour but can't re-find them. In essence, for test and programming, I am looking for a system where I can plug directly into a PCB say a minimum 4 ways of bare PCB holes, and remove after programming and test. Can anyone point me in the righ...

## Low volume PCB fabrication in the Netherlands

Started by in sci.electronics.design4 years ago 14 replies

Hello, I need to find PCB manufacturer for my simple FR4 double-sided PCB prototypes. i dont find much offer on the Web. Anyone can help me...

Hello, I need to find PCB manufacturer for my simple FR4 double-sided PCB prototypes. i dont find much offer on the Web. Anyone can help me ? Thanks a lot. Cheers, Rafael

## Raspberry PI model B + and 5V relay PCB

Started by in sci.electronics.design5 years ago 26 replies

Hi. I didnt play much with RPI but now we have finish one project where we are triggering GPIO. The PCB relay board should be triggered from...

Hi. I didnt play much with RPI but now we have finish one project where we are triggering GPIO. The PCB relay board should be triggered from RPI GPIO and the door should be opened. Now, before i connect PCB to RPI i want to be sure that nothing goes wrong. This is the pcb schematics that we use for the relay trigger. http://tinypic.com/view.php?pic=10rmrsh&s=8#.VFuEUa0zdag What do...

## flexible ribbon "PCB" to regular PCB

Started by in sci.electronics.design4 months ago 28 replies

Looking for good ways to connect / solder a flexible ribbon PCB to a regular PCB, without using a connector. We need to be able to pull hard on...

Looking for good ways to connect / solder a flexible ribbon PCB to a regular PCB, without using a connector. We need to be able to pull hard on the link, without the flexible ribbon coming out. Maybe using Molex Premo-Flex, etc., to avoid having to fab the flexible ribbon? We only need four wires, for an I2C connection. -- Thanks, - Win

## Approximate cost of pcb assembly

Started by in sci.electronics.design10 years ago 9 replies

What is the approximate cost of pcb assembly relative to pcb fabrication for low quantities? If I have 50 boards ordered at about 30\$ each for...

What is the approximate cost of pcb assembly relative to pcb fabrication for low quantities? If I have 50 boards ordered at about 30\$ each for pcb fab can I expect about a 1:1 cost for assembly?

## PCB Turn-key Production Option

Started by in sci.electronics.design5 years ago 3 replies

Shortly I'll be moving one of my PCB designs into production. Several PCB f= ab/assembly houses offer turn key capabilities for PCB...

Shortly I'll be moving one of my PCB designs into production. Several PCB f= ab/assembly houses offer turn key capabilities for PCB manufacturing. They = handle component procurement, bare board fab, and component assembly. I wil= l perform functional testing at my facility so that is not a requirement.= =20 Who have you used? Any recommendations?=20 Thanks, Darol Klawetter

## Looking for pcb manufacturer and assembler

Started by in sci.electronics.design9 years ago 2 replies

Hi, i'm italian and i'm looking for a pcb and assembler manufacturer able to: 1. produce 12layers pcb 2. assembly bga package 3. low cost 4....

Hi, i'm italian and i'm looking for a pcb and assembler manufacturer able to: 1. produce 12layers pcb 2. assembly bga package 3. low cost 4. good for your opinion 5. italian or european Any suggestion?

## PCB routing

Started by in sci.electronics.design9 years ago 5 replies

Hi all ! I'm being project on a based MPC8315E. I have some experience on High Speed PCB routing (DDR & DDRII) but never PCI-e or SATA. I...

Hi all ! I'm being project on a based MPC8315E. I have some experience on High Speed PCB routing (DDR & DDRII) but never PCI-e or SATA. I would be very grateful if someone could recommend me a book on the topic and generally speaking on High Speed PCB guidelines (and theory) Best regards, Habib.

## gluing pcb to wood

Started by in sci.electronics.design8 years ago 36 replies

Can a pcb with standard conformal coating be glued to wood effectively? Or will the conformal coat weaken the bond? It doesn?t need to be...

Can a pcb with standard conformal coating be glued to wood effectively? Or will the conformal coat weaken the bond? It doesn?t need to be extremely strong but I need it where you can't pull it off with your hands or would be very difficult. I should also be able to remove the pcb from the wood if necessary using some flat tool like a scraper or blade(almost prying it off). So basica

## max FR4 PCB temperature and lifetime

Started by in sci.electronics.design10 years ago 5 replies

Hi UL has a rule for maximum temperature on a PCB at 105 degrees C. Standard FR4 can handle 130 degrees, and normally I have used...

Hi UL has a rule for maximum temperature on a PCB at 105 degrees C. Standard FR4 can handle 130 degrees, and normally I have used 95 degrees as a maximum to have long lifetime of the PCB (discolouration and delamination of the FR4) I have tried to find a graph of lifetime versus PCB temperature, but to no end. Have any of you ever seen one? Thanks Klaus

## PCB Testing after Design

Started by in sci.electronics.design5 years ago 12 replies

Hi, I'm a newbie when it comes to hardware design. I have a little bit of exper= ience with PCB design and made a couple of small circuits for...

Hi, I'm a newbie when it comes to hardware design. I have a little bit of exper= ience with PCB design and made a couple of small circuits for learning purp= oses. I need to test out this new PCB designed by another person and its ki= nd of a complicated board with a ton of components on it. It consists of an= ADC and an FPGA and other components that go along with it. It's really si= mil...

## Help duplicating a smd pcb

Started by in sci.electronics.design5 years ago 15 replies

Hi Guys, I'm trying to duplicate the smd pcb that's about 1/4 down on this...

Hi Guys, I'm trying to duplicate the smd pcb that's about 1/4 down on this page. http://members.shaw.ca/novotill/RfProbeSensorMvUw/index.htm See the RF Probe 952001B pcb. I suspect the underside is solid groundplane, but I don't know this. Is there any reason it wouldn't be? Also, 2/3 of the page down, you will see a schematic drawing of a 100 to 1 voltage divider. It is a capacitive div...

## Pcb as heatsink

Started by in sci.electronics.design8 years ago 27 replies

I have a schottky diode (6CWQ06FNPBF) with the following spec - Vf =3D 0.76V If =3D 2.5A Pd =3D 1.9W Tj =3D95.6=C2=B0C I have calculated...

I have a schottky diode (6CWQ06FNPBF) with the following spec - Vf =3D 0.76V If =3D 2.5A Pd =3D 1.9W Tj =3D95.6=C2=B0C I have calculated that the size of heatsink required R=C6=9FH-A =3D 21.65= =C2=B0C/W Is there any hard and fast rule or equation for calculating the size of copper Pcb to get rid of the heat so I can use the Pcb instead of a heatsink if possible as space is at a pr...