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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0
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1answer
75 views

Solder sticks to PCB (not just the pads!)

I'm having a severe problem with solder adhering to the FR4 PCB material. I made my boards (myself, my first time) using positive developer and etchant on a pre-sensitized board. I washed the etchant ...
0
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1answer
52 views

Usart puzzle giving strange output on tx pins

I have tried working out usart peripheral of pic18f26j50 and it found out to be working very well. This one is for a pic18f26j50 in bread board with observing TX pin while transmitting in a loop. ...
0
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1answer
31 views

Unusual Lemo PCB sockets (male PCB contacts, 2-pin 5B, etc)

I am trying to construct a comprehensive Kicad library of Lemo connectors. While working through the "normal" datasheet (unipole_multipole.pdf), I found several combinations appear to be missing. For ...
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1answer
88 views
+50

High EMI PCB track under transistor or diode package

Can a high EMI PCB track under a transistor or diode package (in this case TO247AC) be a problem? To get a better understanding: Is there any advantage on putting these tracks on the other side ...
0
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1answer
80 views

Low-cost Up-Down Servo solution

I have a small project and I'm interested "upgrading" to a more produce-efficient design. Please note I'm no electrical engineer. I want to move a small servo (like this one ...
3
votes
1answer
158 views

PCB design: the setting of the test point and the use of variable resistor

I am designing a PCB circuit and meeting two problems: My design includes a two-stage MFB band pass filter. To make sure the center frequency of the filters is the same, I need to add a variable ...
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2answers
91 views

Washing PCB for picoamp circuitry

I am possibly getting a problem with variation in performance between batches of boards that contain one area which is very current sensitive (to sub nanoamp). Could it be due to manufacturing residue ...
2
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0answers
25 views

GerbV (Gerber Viewer): How to do PNG export of only area within board outline?

Gerbv (open-source Gerber viewer) has the neat ability to export a customizable rendition of a given layer-stackup, to an output PNG. But no matter what I try, I'm unable to come up with any way to ...
2
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1answer
46 views

Is it possible to toner transfer and hand solder MSOP's?

The chip is 3mm by 3mm (10 lead) My printers max DPI is 1200dpi If etching isn't possible, are the MSOP breakout boards on eBay an option? The breakout boards dimension says 1.25mm between the ...
5
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3answers
257 views

Troubleshooting/debugging PCB

This may be an off topic question, but I'm sure many of you have the knowledge and experience to help out here. A quite complicated motherboard was flexed. The resulting symptoms include cross-talk ...
0
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1answer
65 views

Trace aligment in a double sided PCB

Are there any layout requirements/special considerations when routing traces on top and bottom layers of a double sided PCB, e.g. angle between traces, can traces pass beneath an IC, etc? I know that ...
3
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3answers
264 views

50MHz SPI PCB routing, use vias or resistors?

I am trying to route the SPI between MCU and ADC. However, the pin orders between MCU and ADC are not matched, there are crossings. A four-layer board is used.(signal - ground - power - signal) I ...
0
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1answer
73 views

How should Ground vias be placed?

I am using vias to filter the input power. The following to pictures show two ways of placing vias. I think both of them are inappropriate since the vias are not "fully" connected with ground through ...
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0answers
52 views

PCB to schematic

Is there a software package out there that will allow you to layout a board and "populate" it and then render a schematic from that board? I have a few power supplies to fix and no documentation on ...
0
votes
1answer
64 views

Different power sources for pcb

I have a project with arduino. Most devices are powered by the arduinos 3.3V source. But a gsm modem with 5V input and high current consumption cannot be connected with the arduino, because the ...
1
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0answers
73 views

PCB mounting - flatness

Let's say I have a square PCB with mounting holes near each corner and that the PCB will be mounted to an enclosure with 4 standoffs. Is there a rule of thumb about how much tolerance I can have on ...
1
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1answer
28 views

Creating PCB or breakout board for sensor/ICs

I want to buy a BMA180 accelerometer to learn programming SPI and I2C devices (the sensor supports both). This is the link to the sensor on eBay and below is a picture of the sensor: How do I work ...
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2answers
116 views

PCB Track Width for High Current

Let's say I need a 20mm wide trace in 1oz copper to handle some high current. Could I just have a 10mm trace on one side and another on the other side, connected by a plated hole to handle the same ...
4
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1answer
65 views

Calculating differential PCB traces - Edge-Coupled Microstrip

I finally have the microstrip characteristic impedance thing figured out. But now, of course, I need to learn about differential signalling on PCB traces. I've spent some time researching. Here is ...
0
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1answer
58 views

Female Rectangular Headers with Long Pins (Pass-through style)

Female Rectangular Headers with long pins (passthrough style) are used to stack/connect an Arduino shield board to the Arduino board. 1x8 and 1x6 position headers are easily found. Problem: However ...
4
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3answers
345 views

Smaller footprint for capacitors

I'm (again) placing bypass capacitors around an FPGA, and can't seem to get to a sane solution, given that I have all the pins assigned, and the supply pins are right in the middle of the I/O pins. ...
-1
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1answer
78 views

How do you find the right PCB?

This is a stupid question but I don't know much about electronics. I was wondering how one would find the correct PCB for their project? For example, if I wanted to make a portable USB charger, how ...
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2answers
176 views

Is quality China manufacturing possible without being there? [closed]

I'm looking for some help with manufacturing in China with respect to PCB fabrication and assembly, plastic injection molding and metal forging/brushing. Common wisdom in our days is that one HAS to ...
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2answers
140 views

Learning PCB Layout Strategy

A number of projects I have been working on have outgrown the breadboard phase, and I have been learning how to do PCB layout. My first tiny project (a cable adapter) went smoothly, but as I have ...
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1answer
33 views

Assembling JST PH connectors

I assembled a few JST PHR-4 connectors with wires (manually crimped SPH-002T-P0.5S crimp terminals with AWG24 wires and inserted it into the PHR-4 connector housing). When I tried to join connector ...
0
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1answer
55 views

PCB Identification - Many relays, 2 LM2596s, and other power-related components

I'm looking at a board lying around in my home and have no idea what it is, expect for the fact that it appears to be power-related. There's a transformer in the corner, many relays, 2 LM2596s, and a ...
1
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1answer
38 views

Multiple traces for single connection in Eagle

I'm manually routing a power distribution network in Eagle, and am trying to follow the IC vendor's recommendation to attach vias to the power plane both left and right of the bypass capacitor's ...
1
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1answer
57 views

Can I connect all ground connectors via the ground fill?

I am working on a very, very simple two-sided PCB design that connects one 8-pin header with 6 audio jacks, each of which has its right channel and ground connected. All grounds are connected via ...
4
votes
2answers
125 views

Loading firmware via JTAG without soldering on headers every time?

Is there a good way to load firmware onto a PCB that has a 2x5 arrangement of JTAG headers that doesn't involve soldering on pins every time? I tried getting come pogo pins in the hopes of being able ...
1
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1answer
61 views

How many of these UV lamps do I need for PCB fab?

I want to build a PCB UV exposure unit. It will be in a wooden box, it will have lamps and a glass above them. Basic design. For the lamp drivers I will use the circuit from the neon lamps at home. ...
0
votes
1answer
55 views

Connect two boards together after removing Screw Terminals

An adapter board (to a card edge connector like PCI Express x1) is needed to be designed to for the breakout board below. This should involve replacing the board's screw terminals with some male ...
0
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1answer
61 views

Best way to emulate network switching on PCB

I'm interested in wiring up some Raspberry Pi Compute Modules together on a custom PCB board with DDR2 SODIMM connector interfaces. ...
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0answers
21 views

Swapping out circuit board on York AC? [migrated]

I have a York AC unit where the circuit board is shot, so I bought a replacement circuit board (same model). The model number for the board is 031-00251C. Pictures of old circuit board: ...
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4answers
694 views

4 layer PCBs with Fritzing

Can you use Fritzing to create a 4 layer pcb? Also, in real life, what is the maximum limit of layers we can use to create pcbs? is it 4 layers?
3
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1answer
98 views

How to choose PCB manufacturing technology/factory?

I have sent some PCB designs to factories for prototyping. The price, however, varies greatly. Some ask 200USD for a four-layer 5cm*10cm PCB prototyping. While some only ask for 50USD. I assume that ...
13
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1answer
1k views

What's the usage of these holes?

I'm really curious to know what are these holes on this mobile PCB: Are these vias? I doubt they are vias. If these are not vias then what are they? What's the usage of these holes?
1
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1answer
84 views

High voltage/current design on PCB

I am building a circuit that allows me to control a set of light (more specifically Christmas lights you see in supermarkets) with relays (AQH 2223). My idea is to have the controller input on one ...
2
votes
1answer
138 views

Four layer PCB power plane

I need to design a system on a four layer PCB. The layer stack-up from what I know would be signal / components ground plane power signal My problem is, I have a system with a power supply of +-5V ...
2
votes
2answers
145 views

How to determine annular ring width for thru-hole pads?

When placing thru-hole components on a PCB, how do you determine what the annular ring width should be? For example, I'm making a PCB with a thru-hole switch whose contacts are 1.2mm in diameter. To ...
2
votes
4answers
169 views

Should mounting holes be plated?

When putting mounting holes for screws on a PCB, should the holes be plated or unplated? I've read plating the holes provides better support for the screw and helps prevent the PCB from being ...
1
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1answer
63 views

Which Eagle part to use for this 2-pin Screw Terminal?

This is my first EAGLE design and I'm looking to add some a number of 2-position screw terminals (3.5mm pitch) PRT-08084. Problem: I can find the EAGLE part for ...
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2answers
101 views

Layout of 4 layer PCB - pour?

I'm working on a 4 layer PCB with internal 2 layers being power and GND... 2 outside layers are signal. Is it better to have a pour on the outside layers or just leave them empty except for the ...
5
votes
3answers
140 views

Should you try and minimize via quantity?

I have a 6.5" x 4.5" double sided board that is mixed analog and digital. I have partitioned the analog and digital grounds from each other and have zero ohm resistors that bridge the two grounds ...
0
votes
1answer
116 views

Building my own brushless 3-phase motor driver to use with an Arduino

For educational purposes I want to build from scratch a PCB that would allow me to control an hard disk motor I scavenged from the trash. To do so, I was thinking about using AO3400 and AO3401 (PNP ...
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2answers
79 views

2.1 speaker volume controller circuit problem [closed]

I dont know how to connect 4 wires coming out of speaker to the 3.5mm jack whick only has 3 wires in it.... I don't need volume controller. I just want to fix it so that it could work as a stereo ...
9
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3answers
649 views

Does a pin jumper adds noise?

When designing a PCB, is it sensible to use a pin jumper in the pathway of a small current signal (around 0.8 uA) or could there be issues with noise? I would use the jumper to select between ...
1
vote
1answer
81 views

Problem with solder

I'm having problems when I try to solder anything to my PCB. The solder doesn't come off the iron. I can't put nice solder dots like all the people in the videos do. It is really hard for me to put it ...
0
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0answers
48 views

LiPo combination usb/dc/solar charger + fuel monitor

I'm trying to roll several LiPo boards available on Sparkfun/Adafruit into one multipurpose board. Not a very ambitious project I know, but I'd really like an all in one. I've seen Sparkfun's LiPo ...
2
votes
1answer
167 views

About spring loaded solderless connector for JTAG pads

The 14-pin JTAG header on a PCB, JTAG pads without holes, no other holes on PCB around JTAG connection area. Does it exist a special solderless JTAG connector for connecting JTAG cable to such JTAG ...
8
votes
4answers
611 views

How would one attach an optical fibre to a PCB for a display?

For a model train layout, I am looking to route a light to a difficult part of the layout - even the 1.6mm LEDs are too big for the area. It is for display, not data communications. One person has ...