# Tagged Questions

A signal is a stream of information in the form of a varying quantity. Usually in electronics, signals can be in the form of voltages, currents, or radiated electromagnetic fields.

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In Amplitude Shift Keying, the bandwidth required is given by $B=(1+d)S$ where B is bandwidth, S is the signal rate, and d is a value of either $0$ or $1$. But how could the required bandwidth ...
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### Relationship between sampling rate and number of levels/bits in PCM

It is said in the books that increasing the levels of quantisation codes in Pulse Code Modulation, or in other words increase the number of bits, could give a better signal. I understand that having ...
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### Differentiate between clapping and talking

I brought a clap activated switch project to practise my soldering. I realised clap activated was really sound activated. Is there a way I can get it to be able to tell the difference between me ...
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### Simplest 42.8 MHz generator

What is the simplest way of generating 42.8 [MHz] square (or sine) wave? I want to clock fast ADC for SDR purposes. I thought about wideband opamp and 10.7 [Mhz] cystal 4th harmonic. Is there any ...
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### Where should an increase in harmonic frequencies go in the Nyquist formula?

From the Nyquist formula that $Capacity = 2 \times Bandwidth \times log_2(L)$, where $L$ is the level the signal represents, the total number of possible bit combinations the signal can ...
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### Simple power line communication circuit PLC design?

I need simple PLC power line communication design which I could transmit /receive a packet of data through two points ? Any block diagram with little details will be great for me . Update : Data ...
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### Why all digital signals have infinite bandwidth?

Why digital signals have "infinite bandwidth"? Frequency is the number of cycles per second. I have seen before the formula that bandwidth=Maximum Frequency - Minimum Frequency. I remember I was told ...
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### What are Discrete and Continue Frequencies?

When it says "Periodic Digital Signal is composed of periodic composite analogue signal with infinite bandwidth with discrete frequencies" and "Non-periodic Digital Signal is composed of non-periodic ...
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### Why Periodic Signals has only integer frequencies but non-periodic does not?

Why does a periodic signal only has integer frequency values while a non-periodic one has all real numbers as frequency values? The frequency is just the number of times one full cycle has happened ...
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### Video signal attenuation

Which is the best way to attenuate a video signal? I need to reduce the Vpp (Peak-to-Peak Voltage) from 2V of a PAL video signal to 0.75V. I am familiar with filters and amplifiers (like Op-Amp ...
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### Connecting LED to RO pin of RS485 Transceiver

I am using this RS485 transceiver in a circuit of mine and I'd like to place a tiny 0805 LED in series with a 1k resistor coming off of the RO (receiving) pin. I'm hoping this would result in ...
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### Input sound to arduino via microphone jack

I'm designing a gadget which will light up LEDs using a microcontroller. I'd like for it to respond to an audio signal, so I was thinking there are a lot of ways I could do it: If I can accurately ...
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### Problematic electronic volume control TC9176P

I found this site on google while looking for a palce where I could ask electronics questions so bare with me if I'm a bit fuzzy on details and articulation. I have a vintage sony TA-158 stereo amp ...
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### How is phase in a delay system represented by the equation of a straight line with slope equal to -n?

Background: There is delay system concept given in this link: But, I did not understand the phase response of this dely system by diagram. Diagram details are given in this link (crop shown below) ...
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### Why do speakers sound different when they're not fully plugged in?

I've noticed that if there's not a good connection between my jack and the port, like if it's dirty or half plugged in, then the sound is different, but there is still sound, and sometimes twisting it ...
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### How to properly scale, time-reverse and shift a signal?

I'm not sure if this one is on-topic here, but I'll give it a shot anyway. I know that if I have some sort of signal, like for example $y(t)=x(t)$, and I want a signal with twice the frequency, I ...
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### Help Understanding a signal rectifier

I was reading an electronics book and came upon this circuit. I am having a difficult time understanding why the voltage across D1 is 0.6V. I understand that that the reason is because the input ...
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### How termination resistors work; what happens if I use lower values?

I am going to try to interface low-speed 8bit DDR2 chip to FPGA, and I've got some questions crucial to make it work :-) Is that correct that the idea of termination resistor is to sink most of the ...
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### Verifying Cat5e cabling

I have somewhat successfully installed Cat5e cabling in my home, which works flawlessly for 10 and 100 Mbit/s, but I am experiencing severe packets loss at Gigabit speeds, on all of the eight cables. ...
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### Symbol rate (baudrate) estimation

I am looking for a algorithm that can detect the rate of symbols in a base-band signal. The Gardner method is a way to cancel out the timing drift and synchronize the receiver to sender when the ...
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### Signal triangulation

I want to be able to determine the location of an object that will be moving around in a rectangle about 15" X 10" The location must be accurate to within about 1/4" and be measured at least 100 ...
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### Testing a video transmitter for video bandwidth

I need to test the bandwidth of a variety of video transmitters to figure out the maximum resolution I can safely output without losing detail. To this end, I came up with a solution using a TV ...
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### What will happen if I send an analog signal through a digital regenerator?

What will happen if I send an analog signal through a digital regenerator?
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### Voltage transition sense - rapid raise or fall

Which means do we have to sense (relatively) fast voltage transition from one value to another. The exact point of transition start, transition end and the intermediate state. Which schematic gives us ...
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### Why put a resistor in series with signal line?

A lot of times in circuits I see a resistor placed in series in a signal line and sometimes even in series with an MCU's VDD line. Is the intention of this to smooth out noise in the line? How is this ...
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### Frequency Filtration

I have a signal that consists of N frequencies all with unknown phase and frequency(N) = frequency(N-1) + 2Hz. I would like to selectively scale the amplitudes of some of those signals in such a way ...
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### Is there a bidirectional level converter IC for multiple I/O channels?

I have two digital devices to connect, both use 20 data lines but one works at 3.3V and the other at 1.8V, and most of the lines are bidirectional. The operating frequency should be at least 5 MHz. I ...
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### DC power line communications

I want to send a signal through the DC power lines used in railway compartments. Can you please help me to do that, or provide some documents or links?
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### Simple-Coil-less-AM-receiver- how to make for 650kHz (BBC from Poland)

Can enyone help to make it for 650kHz (600-700kHz) for BBC reception from Poland ? After making it does not receive any station. What`s wrong ? ...
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### Signal strength on Freetronics 100% Arduino Compatible Board

I have been using a Freetronics 100% Arduino Compatible board to run switches that trigger sound file players in MaxMSP. The only sketch and patch I could use to get the board and Max communicating ...