Tagged Questions

PCB is the acronym to Printed Circuit Board. A PCB is a carrier for the circuit's components and their electrical connections.

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0answers
18 views

Advice: how to integrate minipci cards to a board design

I'm designing a pcb card for one embedded device based on a Digi iMX28 module. In the design we included a couple of minipcie sockets to add 3G and wifi cards. However, there are two flavors of ...
0
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2answers
51 views

Any simple power supply designs for a 24VAC transforrmer?

I'm a beginner in Electronics Engineering. Any suggestions on simple power supplies with PCB designs which are run by a 24VAC transformer? Thanks!
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1answer
32 views

How to make Eagle package with dual row surface mount tails?

I'm doing a project using the OMNETICS dual-row connectors (http://www.omnetics.com/neuro/pdffiles/A79025-001.pdf). I'm a bit lost about how to make the package for it in Eagle, as the connector has ...
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0answers
38 views

Tango PCB Designer

i'm trying to run the old Tango PCB on a DOSBox, on windows 8.1. I did the same things to make it run that i did on windows 7, but it's not working on windows 8.1, have anyone tried to run Tango on ...
2
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0answers
35 views

How to clean “no clean” flux with a 3L ultrasonic cleaner

I am doing some small batches of PCBs, like 100 each time, using solder wire with no clean flux core. I am using this solder wire ...
5
votes
3answers
515 views

Will solder usually connect copper vias on a 2-sided PCB?

I've seen videos where the board is suspended in a solution with an applied voltage to plate the vias, but I don't really have the resources to do that. Is soldering parts a reliable method to ensure ...
5
votes
3answers
823 views

What to do with unused pin?

I am designing the Vishay VCNL4010 proximity sensor into one of my PCBs. This sensor has an interrupt pin that I don't need to use. Is it OK to just leave this pin floating ("unconnected"), or will ...
1
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0answers
67 views

What is this motherboard component that looks like a bead of solder [photo], and can it be repaired/replaced? [on hold]

As you can see, the one on the top is burnt. Whenever I plug the power adapter into the wall, the component releases a puff of smoke and the adapter instantly shuts itself off. The damage to the ...
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3answers
48 views

PCB trace width calculation

Take a look of this product: http://www.hobbyking.com/hobbyking/store/__68694__HK_Pilot_Power_VI_Module_Distribution_Board_And_Dual_UBEC_ALL_In_One_120A_and_10s_.html It says is a 45 by 45 mm PCB, ...
-1
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2answers
93 views

How do I solder to these pads?

Quick question. I'm trying solder some wires onto the 5 pads (top right of board) in the image. What's the best way to achieve this? I cant get the solder to stick to the board and I have no flux. I ...
3
votes
2answers
260 views

LED that emits light in different direction

Is there such a thing as an LED that emits its light horizontally ("to the side") when mounted on a PCB instead of the ususal "up" direction? If so, what are these called, and do they use the same ...
3
votes
1answer
198 views

Why do they separate some parts of PCBs through making wide holes? [duplicate]

I have seen several PCB that they have wide holes in some their parts (especially the supply of circuits parts). for example take a look at this picture: and on the board: Not sure but I think ...
1
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1answer
34 views

EAGLE PCB, how to specify an out-of-board component?

This might be a very basic question. I have a schematic where some of the components are outside of the board. For example, for a power supply, I have a switch and a transformer that are on the ...
1
vote
2answers
77 views

Which SMD component as IR barrier?

I have a PCB design that uses an infrared proximity detector in the form of an IR LED and an IR transistor placed with about 10 mm spacing between them. Now the problem has arisen that I need some ...
1
vote
1answer
57 views

Does an antenna work inside a plastic box

I need to put two antennas for GSM and GPS communication on my PCB. My final product will be embedded in a user-friendly plastic box with buttons, leds and switches. I have not choosed yet which type ...
3
votes
2answers
286 views

Clock generation on my PCB

I have not a big background in electronics. I am designing a PCB including a MCU (EFM32) and some ICs. I have seen in lots of circuits that they generally add an external Crystal Clock on the board ...
0
votes
1answer
40 views

Serial Connection Not Working on Modified Router [closed]

I have a Sagem F@ST 2504 router. Following the advice from OpenWRT wiki (http://wiki.openwrt.org/toh/sagem/fast2404) I managed to solder the header pins in the correct place. I've attached pics below. ...
0
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1answer
38 views

EAGLE detecting error at Copper Trace intersecting Dimension Outline

The ARDUINO_MEGA part from the Sparkfun Eagle Library is used in my board design. However when performing a DRU check, it seems that there is an error where the top ...
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0answers
35 views

PCB specifications for 2.4 GHZ RF Board

I am designing an RF module with a PCB trace antenna. I'm wondering what PCB specifications will have a significant effect on the quality of the RF Signal. Is there a prefered laminate and immersion? ...
-1
votes
1answer
40 views

What bluetooth chip / type should be used for a remote control car? [closed]

I am building a small remote control car to be controlled by bluetooth (iOS and Android). I am having a custom circuit board built, and I want to know what bluetooth chip I should get. I would like ...
0
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0answers
10 views

DIN 5 keyboard to USB? [migrated]

I have an old keyboard with a DIN 5 connector, I noticed that the wiring on a DIN 5 connector is basically identical to the USB based 4 contact wiring. Can I just blindly wire a DIN 5 ( starting from ...
2
votes
2answers
702 views

PCB design review: Decoupling, bypassing and grounding

I'm trying to make my own wireless sensor using ATmega microcontroller. I've some basic understanding of electronics but I'm a total amateur when it comes to designing circuits and PCBs. This is just ...
2
votes
2answers
103 views

Ethernet 25 MHz and 50 MHz harmonics cuases radiation emission during the EMC lab test

My PCB has been suffering with 25 MHz and 50 MHz harmonics radiation emission. I am using STM32F207 microcontroller operating with 8 MHz crystal. I am interfacing MAC in microcontroller to PHY ...
2
votes
1answer
60 views

PCB assembly cost per-board

I know this question might get closed because of being opinion depended but I couldn't find any answer from google or any other search, so I decided to ask it here. For clarity of question I want to ...
-1
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0answers
33 views

KiCAD footprint of a crystal

I am not sure how to create some not so common footprint in KiCAD. I am using this 40 MHz crystal for my design. The bottom of the crystal looks like this. How can I create those arcs and joints ...
0
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2answers
52 views

Testing a board without placing a component

Is there a way to build a (functional) board without placing 1 component? I am designing a PCB and want to have the option to make it work w/ or w/o placing a specific component (X). This component X ...
5
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4answers
458 views

How can I make a decent ground plane in Eagle?

I've made a couple of simple PCBs as a hobbyist, and for the first time now I want to add a ground plane pour but I'm having some issues. As I have currently understood I need to: Create a polygon ...
0
votes
1answer
49 views

How to explicitly connect hidden pins in eagle?

I am working on a project where I used a shift register 74HC595N which has hidden GND and VCC pins in Eagle. So I used the invoke property as shown in the pics, and connected the VCC and GND to the ...
1
vote
0answers
91 views

Single- vs double-sided PCB assembly costs

I'm working on a new design (still laying out the components) and I have a chance here to reduce the size of the PCB by roughly 40%-50% if I use the other side for a QFP-100 IC (so it's heavy and will ...
1
vote
1answer
53 views

Solder mask for 0.5mm pitch TQFP

I'm using Atmel SAM chips and the data sheets don't have any mention of solder mask clearance for their TQFP packages. What would be a nominal pad/solder mask opening/cream size for a 0.5mm pitch ...
0
votes
1answer
96 views

Suggestions for in-house PCB/FPC lab? [closed]

We are a hardware startup based out of Greece, looking for in-house PCB/FPC fabing solutions/equipment. LPKF's ProtoLaser U3/S look great but they cost $140K and $70K (if I'm not mistaken) ...
0
votes
1answer
54 views

Connecting Terminal Blocks to Second PCB Board

I have a daughterboard with 3.5mm screw terminal blocks (such as Digikey part # 277-5749-ND) that has to be connected to the mainboard, with the daughterboard either parallel or perpendicular to the ...
0
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0answers
27 views

KiCAD pin assigment

What would be the best way to connect multiple pins of a module/footprint to a single pin in the schematic in KiCAD? Do I have to edit the module and set the same pin name for the pins I want to ...
0
votes
0answers
41 views

Mounting a PCB with velcro

I need a lo-fi way of mounting a PCB (Tessel plus RFID card) under a table. The easiest method by far would be velcro but I'm worried about static discharge frying my circuitry. Should I be?
1
vote
0answers
45 views

Qi Receiver on PCB

I'm looking at implementing Qi charging in my project, would it be possible to have a Qi receiver directly on the back of the PCB (copper traces in the shape of a coil)? Could this interfere with the ...
1
vote
1answer
51 views

Orphan polygon not filling

I'm trying to have an area of my PCB with the same geometry on the top and bottom copper layers, but I'm having trouble with the polygon on the top layer. I placed vias on the bottom contacts (which ...
0
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0answers
55 views

Mobile Phone GSM Antennae Used | What are the Latest Types?

What is the best antenna type mobile phones are incorporating nowadays for GSM/GPRS connectivity? Is it PCB etched antennas or anther? I want to know this because mobile phones have the same ...
2
votes
0answers
46 views

Is 3dBi PCB etched GSM/GPRS Antenna Possible?

Is it possible to design a GSM/GPRS antenna that has a gain of 3dBi? if not, what is the maximum gain possible with a PCB GSM/GPRS etched antenna? I'm thinking of a PCB sized 11cm long and 5cm width. ...
1
vote
1answer
98 views

Formula for voltage drop vs PCB trace width, temperature, current, and trace length

I need to find out the voltage drop in the PCB traces with respect to the possible factors like: copper thickness, trace length, trace width, temperature, etc. I found some calculators available at: ...
0
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1answer
57 views

Why should PCB design be mirrored before toner transfer?

I am currently designing a PCB to make with the toner transfer method for the first time. I was reading a guide that said to mirror the image before printing it to the paper. However it seems that the ...
-1
votes
1answer
79 views

What could it mean when a chip will only work right when its hot? [closed]

My screen started dieing like a year ago. Initially, I noticed that when turned on when cold, all I got was snow on the screen. It would quickly go away though as I restarted the screen a few seconds ...
2
votes
1answer
78 views

PCB Crosstalk calculators… Center line distance or trace separation

I am still a beginner in this field, and recently I've learned about Crosstalk and Crosstalk calculators. I've tried the one on EEweb, Saturn, Ultracad and some others. Some of these calculators ask ...
0
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0answers
23 views

EAGLE footprint not sizing correctly

So I had trouble in kicad printing a gerber file with a correctly sized footprint for a generic .1'' 2x20 pinheader. On advice, I switched to EAGLE but this time before I modified any of the parts, I ...
0
votes
1answer
43 views

In Altium Designer, how can you set the autotracer to route all traces with as equal lengths as possible?

Note that this board does not require a power or ground plane, since it's just used to bridge two boards. I want the traces to be as equal in length as possible in order to minimize any difference in ...
2
votes
1answer
53 views

Cutout a polygon from another in any layer in Eagle CAD part creation

I am trying to create a part with a bespoke pad. How do I cut one polygon (for where the hole will be) from the original pad polygon. I don't just want to make a dimension layer and let the PCB house ...
-4
votes
1answer
102 views

Expressing a circuit in the form of block diagram [closed]

I am doing an electronics project for 12th grade in electronics.This project is about water level controller.I have component list along with the description and I have soldered the circuit as told.I ...
10
votes
2answers
740 views

How to route with minimum noise

I'm facing a dilemma on how to route correctly in order to minimize noise on a data signal line. In the example bellow there is a 2-layer flexible PCB (which is very thin). The copper layer is 1OZ and ...
1
vote
2answers
153 views

Complexity involved in building a single board computer [closed]

Our high school has tasked my and a friend of mine with with building a web connected controller for a hydroponics system. The school has budgeted 5k for us to spend as we like, and we are intent on ...
0
votes
1answer
117 views

Is there any problem with soldering a charged battery?

I have a project in mind that amounts to little more than rebuilding a broken eGo-T (electronic cigarette). The battery when I took the busted eGo-T apart had quite a kick and I got a minor burn from ...
0
votes
1answer
59 views

What fedex paper to use for toner transfer

I am very new to creating PCBs and I am planning to make my first one in the upcoming weeks. I noticed that all the instructions and tutorials called for using a laser printer which I do not have ...