# All Questions

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### WHY THE CURRENT IN BULB IS NOT VARYING

When we supply ac power to the incandescent bulb why the bulb voltage does not vary as that of ac waveform.
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### How do i get antennas to transmit my signal? research class

So, for my senior project, I wanted to design a radio receiver and tranceiver. But I haven't taken any antenna course, so i don't have the antennnas to use for transmitting and receiving. What should ...
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### What is the defference between resistors, flip flops and latches?

I want the answer to the very basic level.I know what they mean individual, but what I am looking for is connection between them .
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### SRD-05VDC-SL-C 5V DC relay not working with XY-DJM-5V

I'm just a beginner and need some assistance. below is a diagram of a 4CH reciever which works fine with some leds and it reports 5V positive on Data0 when holding channel 0 on the transmitter. What's ...
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### Energy dissipation in RC circuit given AC sinewave input

I'm implementing a low-pass RC circuit that as an input will have an AC sine wave voltage input. How can I calculate the average power dissipation in the resistor, given R, C, peak (or RMS) voltage ...
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### Neophyte question about AC vs. DC (especially for powering a home)

Here in the United States the electricity grid is AC. I have heard that AC allows transmission of power at greater distances with less loss. However, with the advent of solar panels, it would seem ...
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### Using LPCxpresso with barebones LPC4337 board

I recently purchased a development board on eBay that will allow me to work with NXPs dual core LPC4337 ARM M4/M0 processor. I have experience working with uVison4 from KEIL, for the FRDM-KL25 from ...
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### What is Doppler Spread

What is the plain English explanation of the Doppler Spread? Looking at different sources I come across complicated definitions which I struggle to understand. Example for such one: Doppler ...
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### Using an LPC812 to relay/transform SPI commands

I'm trying to use the LPC812 as a SPI relay between an FPGA and a new FPAA. The purpose is to make the hardware backwards compatible with old firmware by taking old SPI commands from the FPGA and ...
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### Connecting power source to Arduino's 5V pin

I have an Arduino board connected to a Neopixel Ring. This Ring draws more than 0.5 Ampere, so it needs its own power supply (not drawing power via the Arduino board) I found this schematic that ...
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### What are .C1 and .C2 Gerber files in Altium 14?

I am currently working on a project and I'm about to get the Gerber files checked by FreeDFM.com. My question is, in my Gerber files, there are a couple that have the extension .C1 and .C2. In ...
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### Will 74HC595 as LED sink damage LED when pin goes high?

If used as a LED sink, what happens if a 74HC595 pin goes high? Might the LED blow? I expect that when a pin is low, current will sink and the LED will light. What about the opposite condition? ...
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### Two outlets, to power device if either is on

Basically, I have a 120V device I would like to have powered if either/both of two outlets have power. So both could be on, or just one of them. The device itself is typical in that it only has one ...
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### In what situation should I keep the Brown-out Detection feature OFF on a microcontroller?

When the power supply on a microcontroller falls under a certain threshold, a brown-out conditions occurs and RAM memory may get corrupted. Provided that every power down sequence of the circuit can ...
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### How do I keep my constant current source constant?

So I am trying to created a current source that will be used to drain a battery at specific time intervals for a specified duration. simulate this circuit – Schematic created using ...
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### How to keep rarely-used Li-Ion batteries functional?

I have many gadgets around the house that I don't use often, recently I notice that a battery failed on an Mp3 player not used for a year. The battery now has a life of 1 minute from the original 5-7 ...
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### Get peak voltage from RMS power (Audio amplifier)

I want to calculate the peak voltage output of an audio amplifier when driving at its maximum rated power, a loudspeaker. For example, an amplifier rated at 50W RMS into 8 ohms, driving an 8 ohm ...
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### Differential pair output to voltage amplifier transistor

When designing an amplifier stage, like this, how does it work in a linear fashion? Suppose you're applying some feedback, the output may well be stabilized to zero, but the more "wrong" $R_C$ is ...
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### Charging 10 1.2V nicd batteries

I have 10 x 1.2V Sanyo NiCd batteries. They are connected in series. I would like to charge them. The thing is, I don't have a charger. I looked up chargers and they are all quite expensive(I live in ...
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### Theory question about “j” imaginary unit (AC circuit analysis)

I have just started to learn about AC network analysis and have some questions about "j" (or "i" on my calculator), the imaginary unit. My book doesn't go into a great deal about this, and jumps ...
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### Synopsys design compiler- view datapath extraction results

I am using Synopsys Design Compiler(SDC) for synthesis with compile_ultra. This option does advanced datapath extraction which basically tries to group(or chain) ...
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### Help interpreting TIP127 datasheet

I'm trying to build a constant current 2A amplifier using a TIP 127. To be honest, I have a lack of transistor knowledge. I decided to analyze a few existent circuits with a TIP127 and the datasheet. ...
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### LEDs flash at the same time and not one at a time

As you can see on the illustration below, I have a voltage supply (a keyboard made of two piezo elements) with two terminals. Each one drives one LED, but since I've added a buzzer in parallel with ...
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### what is the meaning of Vtt voltage [duplicate]

i am using a digital counter ic which supports differential clock input . the differential clock input can be made compatible with a sine oscillator output using an ac coupling circuit . in the ac ...
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### What is the meaning of Vtt

I was looking at the data sheet of a counter IC and the connection circuit diagram showed two connections: Vbb and Vtt What do ...
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### ADC with programmable quantization levels

Does anybody know if there are ADCs with programmable threshold levels? The continuous signal is a radar signal which is to be digitized with an ADC with controllable qunatization levels. I am not ...
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### overdrive voltage margin to enter MOS into subthreshold and saturation region

What is the equation for Vgs value for any MOSFET in such a way that, Below Vgs, Mos is in subthreshold region, Above Vgs, Mos is in saturation region?
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### Calculate delay in long line

Assume we are connecting a lamp to a source but line (wire) is so long (for example 20Km): Will the lamp bright after connecting the source immediately? how much time it will be? Can we calculate ...
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### AC Linear Actuator Driver for Arduino

For experimental purposes I want to build a 1-axis Polar Tracker and use an Arduino as a PLC unit. As I know it's necessary to use an Opto-isolator to prevent high-voltage from affecting low-voltage ...
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### Wireless sensor network using evolutionary game theory [on hold]

I am new in matlab and i dont have idea about how simulate in matlab the following text a part of Dynamics stability in wireless sensor networks active defense model paper I need help to implement ...
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### Battery Polarity

I was bored at work, and remember when i was little, putting batteries in the wrong way would stop the object from functioning, then decided to try reversing the polarity of the batteries in my torch, ...
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### GPIO Pin configurations [duplicate]

I went through the data sheet of STM32F4 and found the pin configuration of GPIOs. I dont understand the difference between these configurations. • Input floating • Input pull-up • Input-pull-down • ...
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### making Tphl and Tplh equal

Let's say we have the following netlist ...
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### Charging batteries in series when they are connected in parallel in the circuit

I'm new to electronics and I'm trying to build a charging circuit for NiMH batteries. There are four batteries in total. Two are in series, and the other two are in series. Then these are connected in ...
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### Not sure if my calculation is correct, can anyone check this RC circuit for me?

Hello everyone, so in my book I decided to do this practice question but failed to notice that the answer was not given in the back of the book. If anyone can help me confirm my answer I would much ...
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### How to connect the power for VREFSD pin and anlog pin in STM32F3273 (ARM Cortex-M4) for sdadc purpose?

I have an analog amplifier which is powered at single-supply power and have an analog ground of 1.25V. I want to perform sdadc for my analog output. I am using STM32F373 (48pins), which is an ARM ...
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### AC adapter input 220V output 4.5v DC 300mA [duplicate]

We are moving to Denmark and have a Pottery Barn kids Death Star painting with LED's build in that we would like to bring for my son. Here is a link: Currently it has an adapter that reads: AC ...
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### Most energy efficient way to detect motion

I am hacking together a prototype wrist band, with BLE as the main component. I'd like the device to detect a bump or a wave. What would be the most energy efficient way to do so? I'd like the ...
42 views

### Op Amp not providing sufficient gain

Hi friends I am building an Affordable Solar Radio Telescope and for it i need an amplifier..I have built the circuit described in pg 8 of this link. I have built the exact circuit but am using a ...
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### Film capacitors, replacing with ceramics

I've been watching through hole film caps disappear. I've used a bunch of these in thermal control loops, http://www.digikey.com/product-detail/en/ECQ-E1106KF/EF1106-ND/56416 Still making 'em, but ...
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### 5V DC 500 mA adapter run 100 feet to web cam

I am using a GUCE51 USB extender 100 feet from my computer to power a web cam. The extender uses a 5V DC 500 mA power supply. Option 1: Plug the power supply into the 110V AC on the inside and run 5V ...
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### RGB LED Strips with Arduino

I am trying to control an RGB LED strip with an Arduino. I have followed the tutorials in both of these websites: Using MOSFETs: https://learn.adafruit.com/rgb-led-strips?view=all Using LED ...
39 views

### Shannon versus Nyquist bit rate calculations

I am confused with the shannon channel capacity formula Versus nyquist bit rate. nyquist formula contains signal levels while Shannon formula doen't, how to refer to signal Levels in shannon's ...
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### Connecting HiFi Amplifier High-Level Out to Subwoofer Low-Level In

I have an oldish Denon 375rd, with 2 zones but no pre-amp nor subwoofer outputs. I just got a Focal Cub 3 without realizing it's more of a Home Cinema subwoofer and it has NO High-Level Input, only ...
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### How does a Schottky diode work?

There are no spare positive/negative charge carriers on the metal side of the diode, so the spare positive/negative charge carriers on the semiconductor side can not diffuse into the metal and ...
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### Can the Hidden Markov Model be run on an ARM Cortex-M3 processor?

I'm working on an algorithm for a device that utilizes the Hidden Markov Model (HMM) to crunch data and make its predictions. Can the HMM be run on an ARM Cortex-M3 processor running at 32MHz? How ...
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### Designing a current limiting circuit for my project

I've got a small DC brushless motor for which I would like to set a current limiting circuit as a protection against over-current. I thought I could pull it off with a simple fuse (or those current ...
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### How do Coherence Time and Coherence Bandwidth influence the decision on the diversity scheme?

I came across a statement in a lecture slide which states: Coherence Bandwidth and Coherence Time govern our decisions about the diversity scheme that we would choose The lecture is in the field ...