Analog circuits have a range of voltages, rather than just two as in digital logic.
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1answer
28 views
Amplifying analogue audio from an iPhone docking station
So I have an old iPhone speaker dock that broke after I plugged in the wrong cable and fried the microchips on the circuit board. From it however I salvaged the dock connector itself and a couple ...
0
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1answer
111 views
Real-life discrete monoflop
I my current project I need a high-side PMOS to disconnect a load once a over-current or (downstream) over-voltage condition is detected. Obviously without a permanent latch, once the PMOS opens, a ...
1
vote
1answer
855 views
Connecting Altera de2 to a sensor via UART
Is Nios II required when implementing UART core using the SOPC? (or a default Nios is included) I tried writing my own module for the uart connection but it didn't work out. I need a method to ...
3
votes
1answer
171 views
Difference between virtual and ground plane
Ive created two PCBs, a power board to output a +-5V supply and a midway voltage reference (using the TLE2426) at 0V. This PCB powers a biosignal acquistion board shown in the spice diagram below.
...
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1answer
43 views
How do I get antennas to transmit my signal? Research class [closed]
So, for my senior project, I wanted to design a radio receiver and transceiver. But I haven't taken any antenna course, so I don't have the antennas to use for transmitting and receiving. What should ...
4
votes
1answer
48 views
Analog off board connectivity
I have a board that I intend to control with high fidelity differential analog, I'm aiming at one part in 216.
I want to connect the two boards with a COTS connector that solves most of the pick-up ...
4
votes
2answers
207 views
CD4029 does not initialize at 0
I am attempting to build a very simple 4 bit counting machine using a CD4029 ic and a 555 timer. I have built my circuit on a breadboard and everything seems to be working perfectly, however on the ...
0
votes
1answer
58 views
Combine two signals of different frequencies in a test setup
I have a device that is powered from a current source. The current source supplies 10A at 60Hz - the magnitude is roughly 5-10VPP.
I would like to inject another signal on top of that to simulate ...
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0answers
52 views
Why does this State-Variable low pass filter overheat when turning up resonance?
I am trying to build an audio-frequency state-variable resonant filter.
Power supply is ±15V. The circuit contains three TL072 op-amps and three LM13700 OTAs. It receives audio input from -2.5V to ...
1
vote
5answers
168 views
How electrical signals converted into Digital (binary 1 0)
I already ask this question in yahoo and in Microsoft........they say that : did I mean to say how to convert analog signals to digital signals.....and they suggest me the theory of AD converter
So, ...
1
vote
1answer
54 views
Digital light organ
I am trying to make a circuit that takes an audio signal from an MP3 player and converts the signal into digital signals based on frequency.
Audio In is the is the signal from the audio jack of an ...
1
vote
2answers
55 views
Looking for OP-Amp with good rail to rail performance, 5V to 0V [closed]
There are thousands of OP-Amps on Farnell's website, so I thought asking the stack-exchange community might be a good idea. I am looking for an OP-Amp for use in my project.
I currently have an ...
0
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0answers
47 views
Ground Plane, Bypass Capacitors and Differential Pairs
I've placed a KSZ9031MNX Ethernet PHY on my board, and am now trying to get power routed to it. The digital side will merely be annoying to do, I think, but I'm at a complete loss on the analog side.
...
1
vote
1answer
40 views
Three-level analog output (Ground, 2.5V and 5V) - DAC good enough?
I'm planning to replace the thermostat of my evaporative cooler with a Raspberry Pi plus some control (see Wiring a 24-volt Swamp (Evaporative) Cooler for Control With Relays). Signaling from the ...
1
vote
1answer
63 views
How does digital patch memory work on an analog synthesizer?
Not an electrical engineer, but kicking around ideas for a polyphonic analog synth with digital memory, a simplified/modernized update of an older all-analog design.
I've riffled through some of the ...
2
votes
1answer
146 views
What is the simplest analog circuit for integer addition modular 2?
This probably is a rudimentary question. I would like to have a simple analog (switch) circuit for addition modular 2, or \$a_1+a_2+\cdots +a_n \$ (mod 2). Certainly, digital transistors can ...
2
votes
4answers
4k views
Converting PWM into an analog signal
I'm trying to think of the best way to convert a PWM signal into an analog signal. I could use an RC filter, but that requires a very high PWM frequency to create a faithful reproduction of the ...
3
votes
4answers
246 views
Amplifier analog design - how to effectively do it when gain varies so much?
For example, I was thinking about building a small current sensing device that has an display to measure small current draws on some of my circuits. The design would be such that a very small ...
2
votes
3answers
765 views
A good circuit for a large number of push button inputs?
I'm planning to build a kid-friendly "universal remote" so the kids can turn on and off a myriad of IR-controlled devices with one or two easy presses...
The remote is going to have maybe 20 big ...
2
votes
2answers
107 views
Help understanding PIR amplifier analog circuit
I found a PIR amplifier circuit and would like to understand better how/why it works. The purpose is mostly to learn more about analog electronics.
I found the following circuit here: PIR motion ...
7
votes
3answers
2k views
Measuring the phase difference between two signals
I'm looking for an analog method of measuring the phase difference between two signals operating at frequencies in the range from (0 - 20 MHz). I'm wondering if there's an IC that does that or a ...
2
votes
3answers
294 views
Reading 5v analog to 3V PIC
I'm trying to figure out how to connect a linear pushbutton sensor to a Microchip PIC.
The problem is: the sensor has an 5V output and only 3 pins (VDD, Sensor and GND). I need to power the sensor ...
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0answers
86 views
Should my external analog input be isolated?
I want to build a device that samples analog signals from various measurement instruments via their analog outputs. The instruments have their own power supply, and all devices are powered from the ...
3
votes
3answers
627 views
Arduino incorrect readings from analog pin
One of my analog pins, A0, on my Arduino Uno, is not giving totally accurate results. Where as one of the other pins will do a full 0-1023 in a certain use case, the problem pin only seems to be ...
1
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1answer
53 views
Bluetooth Module with Analog Input
I'm building a wearable Bluetooth device. When a button is pressed on the device, it sends a signal to the user's smartphone and consequently an app on said phone. I'm an app developer with no ...
7
votes
1answer
4k views
analogRead(0) or analogRead(A0)
The arduino reference states that you would use the following code to read the value from analog pin #5:
int val1 = analogRead(5);
However to read from digital ...
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votes
3answers
85 views
Transistor resistance for switching analog signals
I would like to use two transistor to switch on/off two paths to an ADC input so that only one path is active at a time. Is this a bad practice? I'm aware of analog switches but don't know if ...
0
votes
3answers
87 views
1:1 and flyback transformer at low frequency and high temperature
I am designing a circuit in that I need 1:1 and fly-back transformers at low frequency (0-100kHz) and high temperature. Can anyone help me with these?
I am looking for voltage being handled around ...
3
votes
1answer
2k views
Making PWM from 2 Analog input in MSP430G2231?
I am a newbie to this MSP430. So, please tell me when I go wrong.
I have a final project making MPPT (Maximum Power Point Tracker) using MSP430G2231. The basic idea is to measure to Analog input ...
1
vote
4answers
719 views
Is the only way to drive a speaker with a positive and negative rail?
I want to create a simple sinusoidal oscillator (Wien-bridge with soft limiting), connected to a high gain amplifier.
I don't have much experience with audio, but I'm guessing a speaker needs a ...
1
vote
0answers
73 views
Digital Latch Circuit with Unknown Outputs
Introduction
I am a student currently enrolled in a digital course course. I'm actually an analog kind of individual so I (like most other analog people) have a hard time understanding logic. ...
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1answer
1k views
Why is my MSGEQ7 circuit giving Arduino analog readings that are so high?
I have built the following circuit based on a proven MSGEQ7 based circuit design, which comes from the datasheet and elsewhere on the internet. I have built and coded to this circuit previously, with ...
2
votes
5answers
871 views
Differential amplifier - what is the differences between CMRR and CMR?
I know that CMRR is Common-Mode Rejection Ratio, but what is CMR?
$$CMRR = \dfrac{A_{dm}}{A_{CM}}$$
I didn't find any mention of it in Sedra & Smith bible.
Does anyone know what CMR is?
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votes
0answers
53 views
How to bias a MOSFET folded cascode transistor using a cascode current mirror?
In the given picture how the folded cascode present at the output is biased. The method used by the author is direct voltage source biasing, but I wish to use a cascode current mirror but facing a ...
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votes
0answers
59 views
State Variable Filter analysis
I'm in the process of making my own adaptation of the classic State Variable Filter (SVF) in the analog domain. Reading up on this article.
I discovered that they use superposition to get the ...
4
votes
1answer
366 views
How do I switch small AC signal on/off electrically?
Suppose I have an audio signal source.
I want to connect and disconnect it to amplifier electrically (for example controlled by another source, like microcontroller, sensor, 555, etc). I don't want ...
0
votes
3answers
89 views
Voltage range shifter from 0V to 3V to -/+1.5V
I'm trying design from scratch (discrete components and opamps) a circuit that could linearly translate from 0V to 3V range to -1.5V to +1.5V. Can someone provide suggestions and designs of how to do ...
2
votes
2answers
98 views
MOSFET behavior with small load resistor
I'm trying to understand the behavior of a MOSFET I got at radioshack (Fairchild IRF510).
I have the circuit set up in the way recommended by the datasheet:
The specifications suggest that it ...
0
votes
1answer
82 views
Analog temperature sensor with 100mV per 1 degree Fahrenheit
My devices only measure analog precision to the nearest 100mV. Most temperature sensors I can find only do 10mV per degree precision. Currently I'm using the LM34.
Is there such a thing as an analog ...
4
votes
3answers
174 views
How to know whether the bandpass filter is stable
I am designing a bandpass filter using MFB. However, I do not know whether my filter is stable or not. Can anyone give me some criteria or methods to evaluate the stability of the filter design?(still ...
2
votes
1answer
220 views
Reducing Undershoot and Overshoot in a custom voltage regulator?
I'm trying to build a voltage regulator that takes in a reference voltage and an unregulated voltage (to power the components, and this voltage is always greater than the reference voltage) and ...
2
votes
2answers
70 views
Why does the “top” transistor in a cascode not set the current?
This has been bothering me for some time. Why is it that the overdrive voltage of the bottom transistor in a cascode controls the DC current, and not the Vgs of the top transistor? Similarly, in an ...
1
vote
2answers
132 views
How can I add three AC signals?
I have three light sensors which outputs appropriate AC currents with respect to light intensities. I only have one pin left for my ADC IC that I have on my board so I can't sample three sensors using ...
2
votes
1answer
123 views
post equalising technique &opamp circuit
I have tried to construct this circuit in LT spice as to compensate the imperfect of DAC of my DDS function generator,for my case fs=125MHz,thus C=6.6pF, and the result as shown :, how do I verify it ...
5
votes
1answer
21 views
ADuC812 needs DAC value written twice. Is that normal/common?
A while ago I had a project that involved Analog Devices ADuC812 microconverter.
Amongst assorted on-board hardware, the device had two very helpful DAC converters, that could source 0-5V on their ...
-2
votes
2answers
115 views
Calculates the volts from CS5530 24-bit AD converter
I have this circuit (Power supply is 5V):
The problem is: How to convert the values to Volts? I get the digital value in 24-bit from spi interface, but I don't know the minimum and maximun voltages ...
4
votes
3answers
453 views
Understanding a circuit for reading current passing through human bodies
I found on Instructables this circuit that is used to detect when two conductive pads are touched at the same time by a person (or, in that particular example, a chain of people).
Used in ...
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0answers
43 views
How to find bias so that OP amp output range is max?
I have a question about (d): I just know that the maximum output may be \$V_{BP2}+|V_{ov7}|\$ and that the minimum may be \$V_{BN2}-V_{ov9}\$.
Can anyone help me?
By the way, I want to check the ...
1
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1answer
65 views
Field programmable analog array
I know and use FPGAs quite a lot between my microcontroller and external interfaces and learned to value the flexibility of this setup.
Now I am wondering whether such a thing exists for the analogue ...
5
votes
4answers
651 views
How are positive and negative feedback of opamps so different? How to analyse a circuit where both are present?
In an opamp, feedback on the positive input places it in saturation mode and the output is of the same sign as V+ - V-; feedback on the negative input places it in "regulator mode" and ideally Vout is ...
