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0
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1answer
76 views

Don't understand spec sheet

I'm planning to buy a photo-interrupter, and I had a look at the spec sheet, but I didn't see much on the current/voltage of the device. I was thinking that it could run on 20mA, but I am confused ...
0
votes
2answers
65 views

A simple device to remotely alert someone [on hold]

We are developing a solution that can remotely alert someone around a relatively small area (around 300 meters). Each user will carry a sort of pager. The server will send an alert to the device. The ...
0
votes
0answers
33 views

Beaglebone black i2c-1 file write error

I am using beaglebone black i2c2 pin 19 and 20 of p9. Somewhere in the bet it was told i2c2 has told accessed with i2c-1 in /dev folder. I am booting default amstrom linux from emmc. Hardware is ...
1
vote
2answers
68 views

unusual transistor markings “C8550”

I am repairing a "wall-wart" charger for a Black and Decker battery powered edger which uses a 12 volt/7 amp hour battery. It has ceased to deliver charge current to the battery but the half wave ...
0
votes
1answer
74 views

Seperate device vs software solution

My apologies, I'm not really sure how to phrase this question. I'm a little confused about what is the advantage of having a separate circuit controlling a module vs connecting the module directly to ...
0
votes
3answers
98 views

What are the big plugs for that you find on high demand devices in North America (120V-Areas)?

Talking about AMEA socket system and 120V. High power demand devices like A/Cs do have bigger plugs with some switches on them. What exactly is their purpose? Seems like a fuse but isn't the socket ...
3
votes
4answers
309 views

Non linear device with two frequencies

I got this on an interview question and I still don't know the answer. What output will have a nonlinear device if we will give two random frequencies \$f_1\$ and \$f_2\$? I answered that it ...
1
vote
1answer
43 views

Determine the output voltage of an integrated ciruit

I'm planning to use an HPA674A (bq25504 EVM) which is based on the bq25504 IC to connect a device (wsn) that works from 2-3.6V which is connected to the Vstor pin and the storage element is connected ...
1
vote
2answers
147 views

How device drivers work

Can anyone explain how device drivers work? I have seen Arduino and other development boards communicating with the PC's USB port with the help of a FTDI chip. This thing can be made to work after we ...
0
votes
2answers
51 views

Devices which consume substantial power in modern embedded real-time systems? [closed]

Could anybody cite examples (if any) of devices and peripherals in modern embedded and real-time systems which consume substantial amount of power compared to modern processors. As processors get more ...
0
votes
1answer
41 views

ATA/ATAPI low level question

I am trying to figure out what exactly is happening on ATA/ATAPI bus right after power-on. From what I understand - host shoud send RESET command, then after some predetermined time send query to ...
2
votes
1answer
161 views

Is there a standard for writing device drivers for microcontrollers?

I have written device drivers for microcontrollers using AUTOSAR. But I was interested in knowing if there are other standards for device drivers. I am planning to write for TIVA TM4C123GH6PM. It has ...
0
votes
0answers
218 views

USB Host vs. Device Detection

Here is a problem to which the obvious answer is "use a switch," but that is not permitted in the design. ;) I am writing software for a USB audio application that is supposed to be able to play ...
0
votes
1answer
128 views

Tech stereo damaged by dimmer switch outlet, why? [closed]

A low end Tech stereo was plugged into an electronic dimmer switch outlet. The stereo was only a few years old and was functioning properly prior to plugging into a dimmer controlled outlet. I ...
1
vote
1answer
103 views

How to design a Circuit that can turn a LED ON depending on the input voltage

I have three LEDs, and I want to turn the first LED ON if the input voltage is 4V , I want to turn the first and second LED ON if the input voltage is 8V and so on. Is it possible to do without any ...
2
votes
1answer
177 views

RFID Based Listening Device

I was just trying to make a passive cavity resonator based listening device just the same way as Leon Theremin did (the great seal bug). I know that I am to use metallized mylar film as the diaphargm, ...
0
votes
1answer
234 views

How can I capture naturally created static electricity so that it won't create a shock when I touch a grounded object [closed]

How can I capture the naturally created static electricity in our bodies, so that it won't create a shock when I touch a grounded object. I'd like to capture it and store it for future use, maybe ...
0
votes
1answer
61 views

Device for recording pic

I'm following this tutorial to make my own recorder PIC18 (http://rengenharia.com.br/?p=401), but I have a problem, I do not have the component "X1" (DB9 female connector for PCB). Anyone have any ...
1
vote
1answer
56 views

Using a Logic Analyzer for Device Drivers (low level)

Sort of a follow up to this question: http://stackoverflow.com/questions/19760764/learning-to-write-low-level-drivers-linux/19761953?noredirect=1#comment29386523_19761953 For example I want to take a ...
1
vote
1answer
105 views

What kind of device is this LT6251 MBR…CT?

Can't find any specs on this device (LT 6251 MBR10100CT or is it MBR|0|00CT or MBRI0I00CT). Can't find datasheet for it.
2
votes
2answers
320 views

Making an obstruction avoiding device without microcontroller

I want to make a toy device which spins to the left whenever there is an obstruction in front of it, without any microcontroller. Can anybody please check whether my approach in building the device is ...
1
vote
1answer
56 views

Optimizing signal voltage level for 5V device

Are there any benefits associated with using lower signal voltages? For example, if a 5V device has an input high voltage level minimum of 2V, would running input signals at, say 3.3 vs 4.5 or 5v ...
1
vote
1answer
624 views

Soldering smallest SMD components such as 0402 with Microscope?

I need to use as small components as possible but I need to do everything by hand. My plan is to use OSH Park for the production of the board. The answers did not focus on whether they used microscope ...
0
votes
3answers
1k views

Cheapest way to build or buy a remote controlled sound maker?

For my high school class's senior prank, we'd like to buy cheap prepaid cell phones (like these: http://bit.ly/VSqOk3), hide them in the ceiling tiles, and then call then randomly throughout the day. ...
-2
votes
1answer
904 views

Home automation appliances wired to micro controller with wireless control from ipad/iphone [closed]

I'm currently going to start developing a media controller for my room. This microcontroller would be controlled wirelessly from my ipad. so there's three parts to this, my ipad, simple ...
2
votes
2answers
144 views

Video camera exposed to lightning in clouds

Suppose you are sitting outside in the dark and the video camera in the mobile is ON. If the clouds are lightning again and again, will this damage the video camera? As our eyes can get damaged by ...
4
votes
2answers
255 views

What is this device?

I found this little device which got my attention. Maybe you can tell me what it is. Is it a I/O board with an OS running on it similar to Raspberry PI? ICs on the device: AMD: AM29F200BT-70EC ...
2
votes
2answers
195 views

Peripheral Devices

I have read few sources that says "Peripheral is a device which is connected to host computer but not part of it. A peripheral is generally defined as any auxiliary device such as a computer ...
1
vote
2answers
761 views

How to create small engine with timer

I'm not sure that this is the correct place to ask, but I have had great success with questions on the other stackexchange sites, so I'll try my luck :) I need a device, which can press a button on a ...
3
votes
2answers
278 views

What would make a laser measuring device more accurate

I was looking a varioos laser measuring devices (laser tape measures). Most of them seem to be accurate within 1/8th of an inch. I'm wondering what the limiting factor for accuracy is. Is it simply a ...
3
votes
1answer
2k views

Streaming camera solutions for RaspberryPi MCU

I'm trying to get a Raspberry Pi MCU to stream an A/V feed over the internet to a web server where I'll have some homegrown software capturing each frame and doing analysis with it. My general ...
3
votes
1answer
801 views

Texas Instruments USB2ANY HPA665

I encountered device made by Texas Instruments with label USB2ANY HPA665. It has LED, mini USB and FloppyDiskDrive-like ports. I can't find any data-sheet, manual or resources what for and how to use ...
6
votes
1answer
100 views

Torque measurement device calibration

I don't know if I'm at the right place to ask this question but here is my trouble : I'm trying to find a good way of calibrating a electronic device used to measure small torques (0 -> 25 mNm). ...
2
votes
2answers
2k views

What is the purpose of a splitter?

I have a splitter SVI Digital SV-2G Splitter (5/1000MHz) from my Comcast high speed internet self-installation kit. I try to understand what a splitter is used for, so I found this Wikipedia ...
7
votes
1answer
363 views

Why are 5 mm LEDs always rated at 20mA?

OK, maybe not all of them, but by far most of the 5 mm LEDs I've ever handled are rated with I(max) = 20 mA and I've been using them for maybe over 15 years. Why is this? Is caused by the size of the ...
6
votes
3answers
281 views

Dead or alive: Operational transconductance amplifier

My first experience ever with an operational amplifier was with an LM3900 from a Philips experiments kit and these kits date from a long way back in time, when I was a young boy in primary school. I ...
-1
votes
3answers
259 views

How to reverse the effect of an alarm?

I am wondering if it is possible to make an alarm that normally operates/sounds when electricity is flowing through a wire to do the complete opposite. The alarm sounds when there is a constant flow ...
0
votes
1answer
131 views

Buying quality electronic devices

As we know there are companies that make cheap and bad stuff and there are others which make good stuff i.e. tested and with warranty. Is there a certified way such as ISO stamps to check for the ...
0
votes
1answer
168 views

ARM Mini Mobile Device Development [duplicate]

Possible Duplicate: ARM Processor on a PCB I'm trying to build a mini device with 3 buttons (that will each preform a task) and it will have an ARM Processor, no screen or form of display, ...
3
votes
2answers
622 views

BJT in Active/Linear mode — How can it still conduct current?

So I've read quite a few books on how BJT's work and all of them seem to gloss over how a BJT in the linear mode with the base/emitter junction forward biased and ...
1
vote
1answer
86 views

Why are handheld devices always backlighted nowadays?

...And mostly, why is it unable to turn this backlight off? Gaming Consoles (and Mobile Phones, PDA's and other handheld devices) are always backlighted nowadays. Older devices, such as the GameBoy ...
2
votes
1answer
318 views

What are power cube transformers?

If I'm not wrong, is the term "Power cube transformers" is less commonly used to refer "A.C/D.C Adapter"? I couldn't find the use to this term.
5
votes
4answers
137 views

How do I get the name or number of device?

In many cases when I am designing a circuit, I use transistors, ICs, etc, by using calculations. But when I go to the market I have to ask the product by its name which I don't know. ...
3
votes
5answers
2k views

How to create a simple audioplayer-device for a single soundeffect

How can you create an audio player device which can play a single sound effect when a button is pressed? A button and the speaker should not be the problem, but the tricky part is, what I have to do ...
4
votes
3answers
439 views

Internet weather device using wifi?

Does anyone know a reference design with bill of materials of less than 30US$ for collecting weather data from the Internet eg. Yahoo's and show it on a LCD? I found many design and dev kits but most ...
2
votes
2answers
437 views

Finding an inexpensive programmable, cellular data device [closed]

I need to find a device with the following characteristics: Programmable. A few kb of ROM will suffice. Can connect to a cellular data network. Has one digital pin input. Power consumption is not an ...
2
votes
1answer
2k views

How to read the device ID of a dataflash memory

I am trying to read the device ID of a serial flash memory by using the SPI connections on an mbed. In the datasheet for the serial flash memory W25Q80 there is this figure. The following is the ...
0
votes
1answer
141 views

How to read this table in a datasheet

I'm trying to get the device ID out of dataflash memory using an mbed. I'm trying to understand this table that is in the documentation for the memory. I understand that ABh, 90h, and 9Fh are the ...
6
votes
6answers
581 views

Could induction thaw ice?

Last week we had very cold weather; and as a result there were lots of frosted pipes (iron and plastic). I spent a lot of time defrosting metal pipes with a torch, but could not do the same with ...
2
votes
2answers
412 views

What is this part: 2n2 630?

I'm trying to identify a part I removed from a compact fluorescent lamp manufactured around 9 years ago (date on the PCB is 17.12.01). It is a gray hexahedron and it's 7 mm wide, 2 mm long and about ...