117
votes
3answers
24k views
What is it that strips vocals from audio when a 1/8" audio jack is partially unplugged?
Every once in a while, my eighth-inch audio jack will slip loose and I'll seemingly lose only the voice part of a track -- leaving somewhat of a "karaoke" version. What I would guess about how audio ...
111
votes
29answers
14k views
Good Tools for Drawing Schematics
I was going to add a bit of information to my post on a previous day using schematics and some instructions. What programs are being employed for this purpose.
I mostly want to see what others are ...
93
votes
8answers
6k views
Why does USB have 4 lines instead of 3?
USB specifies 4 pins:
1. VBUS +5V
2. D- Data-
3. D+ Data+
4. GND Ground
Why is this not 3? Could the Data and Power not share a common ...
87
votes
29answers
13k views
Basic Electronics Book
I need basic electronics books (diodes,transistors,current..etc) as I am just starting out with electronics and want to have something to read over the holiday.
Any suggestions of good beginners' ...
70
votes
1answer
6k views
Rules and guidelines for drawing good schematics
We see a lot of poorly drawn schematics here. A few times people have actually asked for critiques of their schematics. This question is intended as a single repository on schematic drawing rules ...
60
votes
12answers
17k views
What's the difference between a microcontroller and a microprocessor?
What's the difference between a microcontroller and a microprocessor?
56
votes
14answers
13k views
Is C++ suitable for embedded systems?
A common question, here and elsewhere. Is C++ suitable for embedded systems?
Microcontrollers? RTOSes? Toasters? Embedded PCs?
Is OOP useful on microcontrollers?
Does C++ remove the programmer too ...
55
votes
7answers
7k views
Best One-Off DIY PCB Creation Technique
I have finally built up a lab to design electronics in. I have quite a few designs I would like to test. I have tried the printer toner/iron technique a few times but have found that I cannot create ...
55
votes
9answers
2k views
How does the current know how much to flow, before having seen the resistor?
With the following circuits as examples :
and
How will the current I know how much to flow?
Would any other wave travel first in the circuit and then come ...
53
votes
7answers
11k views
Decoupling caps, PCB layout
I guess I've been somewhat ignorant when it comes to the finer details of pcb layout. Lately I've read a couple of books that try their best to lead me on the straight and narrow. Here is a couple of ...
53
votes
4answers
2k views
Can microcontrollers be run at arbitrarily low clock frequencies?
The datasheet for the ATTiny13A, for instance, lists Min frequency of 0 MHz. Does this mean the clock can be run at any arbitrarily low frequency with no ill effects? I'm assuming it draws lower ...
50
votes
10answers
3k views
What's the cheapest way to link a few microcontrollers wirelessly at low speeds over short distances
What's the cheapest way to link a few microcontrollers wirelessly at low speeds over short distances.
I'm looking to keep it ultra-cheap, use common discrete parts and keep it physically small. I ...
49
votes
6answers
11k views
What is the difference between Vcc, Vdd, Vee, Vss
I've seen lots of schematics use \$V_{CC}\$ and \$V_{DD}\$ interchangeably.
I know \$V_{CC}\$ and \$V_{DD}\$ are for positive voltage, and \$V_{SS}\$ and \$V_{EE}\$ are for ground, but what is the ...
48
votes
6answers
7k views
Should chassis ground be attached to digital ground?
I'm working on a PCB that has shielded RJ45 (ethernet), RS232, and USB connectors, and is powered by a 12V AC/DC brick power adapter (I do the 5V and 3.3V step down on board). The entire design is ...
45
votes
9answers
8k views
Are solder fumes bad for me?
I do a fair bit of soldering (lead-free). Is breathing in solder/flux/paste fumes actually going to harm me?
Are cheap fume extractors worth buying?
44
votes
10answers
7k views
Why are there no 256-bit or 512-bit microprocessors?
In an 8-bit microprocessor its data bus consists of 8 data lines. In a 16-bit microprocessor its data bus consists of 16 data lines and so on.
Why is there no a 256-bit microprocessor or a 512-bit ...
43
votes
11answers
33k views
What is a decoupling capacitor and how do I know if I need one?
What is a decoupling capacitor (or smoothing capacitor as referred to in the link below)?
How do I know if I need one and if so, what size and where it needs to go?
This question mentions many ...
43
votes
4answers
2k views
What is the reason that the value “47” is so popular in electrical engineering?
We often see component values of 4.7K Ohm, 470uF, or 0.47uH. For example, digikey has millions of 4.7uF ceramic capacitors, and not a single 4.8uF or 4.6uF and only 1 listed for 4.5uF (specialty ...
39
votes
9answers
3k views
How can anyone use a microcontroller which has only 384 bytes of program memory?
For instance a PIC10F200T
Virtually any code you write will be larger than that, unless it is a single purpose chip. Is there any way to load more program memory from external storage or something? ...
39
votes
3answers
18k views
Choosing power supply, how to get the voltage and current ratings?
Power supplies are available in a wide range of voltage and current ratings. If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to ...
38
votes
9answers
2k views
RTOS for Embedded Systems
I have seen many articles that tell me I should be using RTOS for time management and resource management. My time has not permitted my own research, so I come to chiphacker for advice.
I use low ...
37
votes
5answers
2k views
What is impedance?
This is presented as both a resource for the community and a learning experience for myself. I have just enough knowledge of the subject to get myself into trouble, but I don't have the best grasp of ...
36
votes
5answers
5k views
My linear voltage regulator is overheating very fast
I'm using a 5V/2A voltage regulator (L78S05) without a heatsink. I'm testing the circuit with a microcontroller (PIC18FXXXX), a few LEDs and a 1mA piezzo buzzer. The input voltage is ~24V DC. After ...
36
votes
11answers
3k views
When to avoid using a breadboard
What are the cases where one should avoid using a breadboard? e.g. high frequency, noise prone circuits etc.
36
votes
7answers
10k views
How much does it cost to have a custom ASIC made?
I have browsed several ASIC manufacturer's webs, but I haven't found an actual number.
I assume there would be a fixed cost associated with creating masks and such and then there will be a cost per ...
36
votes
3answers
1k views
Why are they called breadboards?
Why are solderless protoboards called "breadboards"? I've used the term for decades but couldn't answer a student's question about the name.
36
votes
8answers
3k views
36
votes
2answers
3k views
Lightning bolt vs. batteries: a coulomb in everyday terms
I am trying to decide if the information on the wikipedia page
http://en.wikipedia.org/wiki/Coulomb#In_everyday_terms
is reasonable. In particular the statements that a lightning bolt has about 15 ...
36
votes
6answers
8k views
What is the difference between a DSP and a standard microcontroller?
I understand that a DSP is optimized for digital signal processing, but I'm not sure how that impacts to the task of choosing an IC. Almost everything I do with a microcontroller involves the ...
34
votes
17answers
4k views
What are good microcontrollers available today?
I have experience with assembly and C programming for microcontrollers, but I'm not familiar with the various MCU and DSP families offered by today's companies. (eg: Texas Instruments, Atmel, Renesas)
...
34
votes
6answers
5k views
Does turning a lighbulb on and off repeatedly use more energy than just leaving it on for hours?
Let's say I have a 60W bulb in a lamp in my bedroom. If I kept the lamp on for 2 hours straight but the next day, I switched it on and off 10 times in intervals of 5 minutes. Which scenario would use ...
32
votes
9answers
3k views
What's so great about ARM?
In a comment to this answer Kortuk asks what the ARM advantage is. I first added some arguments in my answer, but I think the question is interesting enough to be a question in itself, so that more ...
31
votes
9answers
2k views
What exactly is voltage?
Bit of a strange question, but what is it? My physics teacher said it was kind of like a "push" that pushes electrons around the circuit. Can I have a more complex explanation? Any help is much ...
31
votes
13answers
3k views
What are low cost circuit and PCB design software?
Do you know of any freeware or low cost circuit / PCB design software?
I know a few which I have listed below but I was wondering if there were more of its kind. Please mention the good features and ...
31
votes
5answers
5k views
31
votes
7answers
1k views
What should a contract Electrical Engineer Deliver once a project is complete?
I'm getting ready to hire an electrical engineer for a small contract job - creating a prototype. What I'd like to know is, what should I have him deliver to me when the project is complete?
I ...
31
votes
3answers
5k views
Which products should have FCC certification and about how much does that cost?
I'm aware that nobody actually does this at the hobbyist level, that successful commercial products have been launched without certification, and it's probably something I can't afford if I have to ...
30
votes
6answers
10k views
Why was Mini USB deprecated in favor of Micro USB?
Mini USB connectors were standardized as part of USB 2.0 in 2000. In 2007, the USB Implemeters Forum standardized Micro USB connectors, deprecating Mini USB connectors four months later.
Why? What ...
30
votes
7answers
20k views
How to get more than 100mA from a USB port
I heard that the current limit for a USB port is 100mA. However, I also heard that some devices can get up to 1.8A from a port. How do you get past the 100mA limit?
30
votes
14answers
3k views
Version control systems for hardware projects?
What are some of the good versioning systems for hardware projects? Is there equivalents of Google Code, CVS and SVN? Are such version control systems suitable for hardware projects involving PCB ...
30
votes
15answers
331 views
What microprocessor for experimentation?
I harbor a secret fantasy (oops, not so secret anymore) to build a simple computer from scratch. I'm looking for an easy-to-use microprocessor to start with. I know about the usual suspects such as ...
29
votes
3answers
2k views
What's this importance of datasheets?
As someone starting with electronics I keep hearing, "Check the datasheet!"
Why are datasheets so important and what information can I expect to find in them? It seems like a large amount of ...
29
votes
8answers
2k views
What tools, equipment, and techniques do you use to solder fine-pitch SMT parts?
Possibly many questions have been asked on soldering smd parts, but I haven't found specific answers, Like:
Do you use a watchmakers lens or some other type of magnifying glass while soldering these ...
29
votes
4answers
1k views
Why aren't decoupling caps built into the IC or IC package?
The title is probably good enough, but I've always wondered why decoupling caps aren't built into the chip or at least the IC packaging?
29
votes
4answers
23k views
What are the different types of solder used for?
How do I know when to use lead, flux-core, lead-free, or any other kind of solder out there? Do you have any tips on solder gauge for specific applications?
28
votes
7answers
12k views
What are the freeware SPICE simulators available?
Does anyone know of a freeware SPICE / circuit simulator? SPICE (Simulation Program with Integrated Circuit Emphasis)is a general-purpose, open source analog electronic circuit simulator. It is a ...
28
votes
5answers
6k views
How many GPS channels make sense?
You need 4 channels to determine your position (including elevation), and I can understand that a few extra channels increase accuracy. However, there are maximum 12 satellites in view at any time, so ...
27
votes
15answers
14k views
How do you cut PCB?
I just spent about 20 minutes trying to cut through a PCB with a hacksaw. These things are really tough.
What is the correct tool to cut PCB material, and get a nice straight line?
I saw something ...
27
votes
1answer
955 views
How can I efficiently drive an LED?
I understand that I can not connect an LED directly to a battery because it will draw too much current. Thus, there must be something else in the circuit to limit the current. What options are there? ...
27
votes
8answers
2k views
Why do utility companies supply at a frequency of either 50/60 Hz?
It just struck me that Utility Companies world-wide supply domestic users at either 50/60Hz. It could have been selected to be 10 Hz, or 100 Hz ... whatever
Was 50/60 chosen at random? Is there some ...
