1
vote
1answer
38 views
How to plug 2 5m RGB LED light strips together?
I got two 5 meters RGB LED light strips and would like to connect them together, controlling them as a single strip.
Each strip power is 72 W, the input voltage is 12V, it has 300 5050 SMD LED ...
2
votes
3answers
116 views
What do you use a board like this for?
I'll start by saying that I'm a software guy, I know literally nothing about electronics.
I recently bought a raspberry pi, and while browsing at my local electronics shop, saw this board for $5.
...
1
vote
2answers
102 views
Using forward voltage drop of diodes with linear regulator
I want to clamp the output of a adjustable three-terminal linear regulator Vout to -1.8V relative to a reference voltage Vref.
My approach is to use the forward voltage drop of three diodes but I am ...
2
votes
1answer
74 views
Two questions, caps again
If I discharged my caps on thick bronze rails connected to the caps by copper wires and nothing else, would that be dangerous? I'd like to safely discharge the caps as fast as possible for the ...
4
votes
3answers
104 views
five month countdown timer circuit?
I'm a beginner in electronics, so I just have an idea in my head and don't know how to actually make it. I want to make a countdown circuit, for an event in next 5 month. The display format is like ...
-1
votes
0answers
29 views
Does anyone know of a good starting point for learning about Spartan 6 LX45 boards? [closed]
I have no idea how or what I can do with this FPGA, but I want to learn. I have a background on some digital logic and I'm working on Verilog now, but I was wondering if anyone had knew of a good ...
0
votes
2answers
45 views
Minimum files for Atmega1284p AVR-GCC?
does someone have the minimum setup (ie. a 1284p Makefile and an example blink.c) for an ATMega1284p and AVR-GCC? I seem to be ...
3
votes
0answers
35 views
Programming an ATmega1284p with Arduino IDE and internal RC Oscillator?
I'd like to program an ATmega1284p with my AVR Dragon and the Arduino IDE. So far I have installed mighty1284p (http://maniacbug.wordpress.com/2011/11/27/arduino-on-atmega1284p-4/), after writing my ...
3
votes
2answers
114 views
Can two electrolytic capacitors be made into a bipolar?
I know if you put an electrolytic capacitor backwards they explode and it's quite fun to observe them exploding. I am wondering if you can use two of them (and some diodes) to turn it into a bipolar ...
0
votes
2answers
45 views
Sending CAN protocol data(1Mbps) via serial port
I would like to build a tool for viewing CAN protocol data on my computer. The CAN protocol data is captured using a microcontroller (STM32F4 discovery board) and sent to a PC via a serial port. My ...
0
votes
1answer
34 views
xilinx schematics to truth table
I have a somewhat complicated Schematics design. Is there a program which could convert my design into truth tables?
If there is no such program, how can I represent the D flip-flops of the following ...
3
votes
3answers
74 views
Energy efficient one button on/off with extra function
(Old) cellphones have a button to turn it on (when off), end a call (when on, short press) or turn it off (when on, long press).
I need something similar for a microcontroller. The device is ...
0
votes
0answers
39 views
Erlang B telecom system (grade of service)
I am bit stuck with an answered question that I found online:
We have an Erlang B system where the total number of served call is 15.48 erlangs. The system contains 23 circuits. The incoming calls ...
0
votes
0answers
14 views
usb example project Qt
Hi I am using Qt on my beagleboard xm and I am trying to find usb examples to start with. I m not able to find many. Could anyone show me some examples?
3
votes
1answer
119 views
What are those black things on the board?
I'm a beginner in electronics, and I'm ignorant of many basic things.
Check out these black things on the board:
These are from a capacitive keyboard.
I'm disassembling it and I want to connect ...
1
vote
1answer
27 views
Connect 8051 serial port to multiple 8051s
I want to design a project in which one supervisor 8051 communicates with four other 8051s. I'd like the students to implement this project with some server-client view. That means that the TX port of ...
-5
votes
0answers
38 views
Questions for Exam Test in Semiconductor Elements [closed]
Questions may be found in the link below:
Task List
Answered needed by Sunday night. Thankyou.
-2
votes
2answers
72 views
Why aren't coupling capacitors used in a basic BJT diff amp?
In a basic BJT differential amp it is mentioned that since both positive and negative biased voltage sources are used the need for coupling capacitors is eliminated. I don't see the relation and why?
0
votes
2answers
68 views
PWM Control with MOSFET switch
I plan on using a 555 timer for a PWM signal (variable with a potentiometer) and a gate driver to use a MOSFET as a switch. Essentially, I am trying to take a +300V rail and "step" it down using the ...
-4
votes
1answer
76 views
Cow tipping robot plans [closed]
Does anyone have plans for a cow tipping robot? Its hard to do by hand so we are thinking a robot would be good. I remember seeing a robot wars or some other show where one bot tried to tip another, ...
1
vote
1answer
41 views
Why is the output from this astable 555 the reverse of it's simulation?
The simulator in LTSpice looked OK ... so I moved to the breadboard with an LED (eventually replaced the LED with a buzzer) at pin 3. One more difference in the assembled circuit is the condenser at ...
3
votes
1answer
40 views
Arduino Runing On && Charging NiMH batteries
I have a project I'm working on that will have an Arduino running on 2 or 4 rechargeable NiMH AA batteries. I say 2 because I might boost up the voltage to what's needed. My problem is that this ...
0
votes
2answers
59 views
Find the current in the circuit after 20s if the initial current was 0
An inductor in an electric circuit is essentially a coil of wire in which the voltage is affected by a changing current. By definition, the voltage caused by the changing current is given by ...
3
votes
2answers
83 views
What is the purpose of capacitors and resistors in this USB bus?
Trying to understand the purpose of the capacitors and resistors in this bus powered configuration for the FTDI chip, I think the capacitors are for filtering high frequency noise, not sure what the ...
1
vote
3answers
46 views
Arduino and FTDI Communications
Short Version
Can I make a serial connection from an Arduino to a device with an FTDI connector?
Long Version
I have a wifi shield for an Arduino that is misbehaving. I know their is an FTDI ...
-1
votes
0answers
81 views
Turn on computer by cell phone but not when it's already on [closed]
I am newbie in electronic engineering. I'm trying to turn on my computer by calling my cell phone. I toke two wires from the vibrator of the cell phone and that's fine, but I don't want to turn off my ...
1
vote
0answers
83 views
ATX power supply front-end: How does this work?
I've been trying to educate myself on general power supply operation and stumbled across several schematics for ATX power supplies. In general I understand how a SMPS operates, and an ATX PS is just ...
3
votes
4answers
270 views
Why are high end audio connections gold?
Silver has a lower resistivity than gold and is cheaper, so why are high end audio components gold plated?
2
votes
2answers
50 views
On multi master i2c bus how to determine which device is the master of the bus?
On a multimaster i2c bus, how to determine which device started the transfer?
2
votes
6answers
90 views
Switch transistor with a low voltage and current
I'm designing a circuit that will use a combination of switches and resistors to allow a microcontroller to identify which switch was pressed based on the voltage read and perform a switch-specific ...
0
votes
1answer
45 views
Frequency of fluctuations in power in an input power design circuit
I am thinking about the following power design circuit in section 6.1 : http://www.arndaleboard.org/wiki/downloads/supports/BaseBoard_Specification_Arndale_Ver1_0.pdf
Is it possible to calculate how ...
1
vote
1answer
40 views
Accurately measure relative intensity noise (RIN) using RF spectral analyzer?
I'm trying to measure the relative intensity noise (RIN) of a laser using an RF spectrum analyser. It's a fairly common method (outline: ...
2
votes
2answers
58 views
How to connect sensors to an Android device?
I need to build a device, which measures several parameters (body temperature, conductivity and pulse) and transmits them to an Android mobile device.
The system has following parts:
The sensors
...
5
votes
1answer
50 views
Is mVtt the same as mVpp?
I am designing a driver circuit for S/PDIF, and in a couple different places, like this one, it specifies an amplitude of 500 mVtt. I'm not familiar with those units, and googling gives me nothing. ...
3
votes
1answer
54 views
Vinyl player emulation on Arduino
Say, you have an arduino uno + audio shield, a speaker and a jog-wheel (or mouse scroll-wheel).
And you want to play some audio-file tied to the movement of the wheel, just like you move vinyl disc.
...
1
vote
1answer
29 views
Faster IO on ARM Cortex-M3 (Sam3x8e) than PIO_SODR and PIO_CODR?
I have a very simple C program that toggles a pin on a Cortex-M3 board (SAM3X8E) with a 84MHz clock speed. I built this using Atmel Studio 6.1.
...
0
votes
1answer
19 views
xbee and interoperability
i'm studying interoperability in the telecommunication field and i want to know we must do what to have an xbee module interoperable with other zigbee devices of other manufacturers (not Digi). I ...
0
votes
3answers
66 views
How to read RPM from 3-wire fan - PIC18F4550
I am working a PIC µC project. I am using 12VDC PC fan (Coolermaster) for my application. A part of the project is to return the RPM from the third wire of the fan to an LCD.
First of all, How can I ...
2
votes
3answers
74 views
Slowly turn a planisphere at the sidereal rate
My problem is to rotate a planisphere (a star chart) at the sidereal rate.
I will set the planisphere to its initial position manually, then turn on some device which rotates the planisphere on its ...
2
votes
3answers
114 views
Do I need to use thermals on vias for reliability?
This question is further to Why thermal reliefs on vias?
I have recently been advised (by someone I consider an expert) that I should add thermal reliefs to vias which are connected to planes, even ...
-2
votes
0answers
35 views
How to design a filtered power supply? [closed]
The filtered power supply that must be design can produce dc output voltages of +10V (+-) 10% and -10V (+-) 10% with a maximum load current of 50mA. The voltages are to be switch selectable across one ...
0
votes
3answers
64 views
Synchronizing SPI ports for higher data rate
I am designing a new board which uses the NXP LPC4330 (Cortex M4 microcontroller) with a XESS Xula2 FPGA development board. In this design, the Xula 2 has limited I/O pins since it is designed to fit ...
6
votes
4answers
102 views
Can I achieve a one shot button without a 555?
I have a complex circuit, but my problem only relates to one small part.
I have a relay, which is energised by pulling the low side low using an NPN. I would like a pushbutton to operate the ...
-2
votes
1answer
78 views
what is the gain of this amplifier at resonance frequency?
I want to analyze this circuit but I do not know how to compute its gain at the resonance frequency.
In lab its gain at resonance frequency (910kHz) was 54.
5
votes
4answers
183 views
What's an easy way to supply power to a breadboard without using batteries?
There are a number of kits available (for example sparkfun's Breadboard Power Supply USB - 5V/3.3V and Breadboard Power Supply 5V/3.3V or Adafruit's Adjustable breadboard power supply kit - v1.0) but ...
0
votes
1answer
75 views
What kind of oscilloscope is good? [closed]
I want to buy an oscilloscope as a gift of Father's Day to my Dad. I have no idea what kind of oscilloscope is good? Is there any kind-hearted friend can help me? Thank you in advance!!! :-)
-1
votes
0answers
41 views
Temperature sensor issue [closed]
I am implementing home automation using an MSP430F2274. For that I need to read a temperature sensor and send the values to the receiver side. Please suggest any manuals to write code?
-3
votes
0answers
35 views
How to Start with Pic18f controller and ENC28J60 configuration [closed]
I am a newbie to ethernet control operation using pic18f controller and dont know how to configure my Olimex ENC28J60-H Board with PIC18F controller using SPI communication. However i have written ...
0
votes
1answer
33 views
Kicad: How to add a Filled Zone around a Net with a single pin?
I am designing a PCB in Kicad and I need to add a filled zone around a single pin (pin needs to become part of the zone, not an island).
For some reason, when the "Copper Zone" tool provides me with ...
0
votes
1answer
65 views
Is it possible to build a CPU from content-addressable memory?
Every modern programming language use objects and not C/C++ style struct/class.
In C/C++ every data member has a size, so addressing a struct member is basically a memory address + offset. But script ...
