Analog circuits have a range of voltages, rather than just two as in digital logic.

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super heterodyne receiver - problem [on hold]

As a part of my project, I have 2 problems: What type of frequency discriminator is used to find what frequency I am receiving from a band of frequencies between 64KHZ to 240MHZ. what is the ...
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0answers
50 views

ATTiny85. How do I use the reset pin as an analog input or digital output?

According to this datasheet, the ATTiny85 has 6 I/O pins if we include the reset pin. I used five of them to charlieplex 18 LEDs and I need another one to use as analog input. Would it be possible to ...
2
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2answers
91 views

Designing a stiff voltage source using an emitter follower

simulate this circuit – Schematic created using CircuitLab I am new to electronics, and I am trying to do Exercise 2.2, page 67 of The Art of Electronics. Use a follower with base ...
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4answers
105 views

Simplest possible way of latching the voltage peak?

I have an input signal like this. I wish to display the highest voltage for a period of time with LED. So I need to retain the highest voltage until the next new highest voltage comes. I tried D ...
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2answers
69 views

Converting mark space ratio to DC

I have a pulse which varies between 500 Hz to 100 kHz where the quantity I need is the mark space ratio, I'm not interested in the frequency here although it must affect the design. What I've come up ...
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1answer
44 views

Analog PWM generator from 0%

I have to prepare easy analog PWM regulator which can operate from 0% (0V). I know that one 555 can't do that... Do you know any circuit that can handle that?
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37 views

where i can find solution manual to Foundations of Analog and Digital Electronic Circuits? [closed]

its link on amazon is http://www.amazon.com/Foundations-Electronic-Circuits-Kaufmann-Architecture/dp/1558607358/ i have google for hours and cannot find its solution manual, so where i can get its ...
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1answer
63 views

Compromise needed combining virtual grounds

This is a long story for which I hope my proposed solution to a problem I've created will be a stable one. But op amps can surprise you, so let me explain. The circuit is large and complex, so I'd ...
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16 views

Flex sensors and pinoccio Interfacing

So I'm planning to interface these flex sensors https://www.sparkfun.com/products/10264 with a Pinoccio: https://pinocc.io/ Since the onboard ADC accept voltages till 1.6 volt and i need to ...
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2answers
113 views

Why does an op amp need to be powered before applying the input signal?

I was taught that a power supply needs to be applied to an op amp before an input signal. I understand that doing that in the wrong order fries the chip, but why?
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1answer
57 views

Direct interfacing of analog MEMS microphone to microcontroller ADC

I would like to sample the output of an analog MEMS microphone with an ADC embedded in a uC, sampling rate up to 1MHz. I don't care too much about signal quality (as I'm more interested in ambient ...
0
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5answers
158 views

Simplest analog circuit to compare two song signals?

I am trying to build a simple analog circuit that compares how similar two song signals are. One signal is the song sung by me, for example, and the other signal is the reference song signal. Since ...
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1answer
32 views

How do I find the corresponding level of those audio samples?

I am trying to self-study this problem for a future exam. The writings in red are solutions to the question. I have a problem in number part e of the question where they find the corresponding level ...
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1answer
98 views

What does lumped element mean?

Can anyone explain me the meaning of lumped element and lumped circuit abstraction in detail. What does lumping or discretizing matter mean?
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2answers
95 views

PFET to turn on/off system power

I have a Raspberry PI board connected to some external circuitry, and am using Microchip MCP23008 I2C GPIO expander chips to control external LEDs and motor circuitry. One important part of this ...
1
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2answers
77 views

Pressure gauge with analog output [closed]

I have a circuit that needs to electrically output a pressure value and display it using analog dial gauge. First I wanted to use regular round ammeters but they don't look like "real" pressure ...
0
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1answer
33 views

Are NTSC and PAL affecting display rate

I understand that the NTSC TV signal is 30hz and PAL is 25hz, but if NTSC and PAL are TV signal standards how could they affect display rate(Hz) for input devices e.g. when you connected and old game ...
2
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1answer
55 views

Question related to Cascode Circuit

I am trying to solve the following question related to cascode circuit. Where T5 has Vbe=0.7V I have answered the questions as follows. - Explain how the circuit works? The circuit has a DC ...
2
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5answers
107 views

Calculating output impedance of Vbe multiplier

I am trying to calculate the output impedance of the following Vbe multiplier, simulate this circuit – Schematic created using CircuitLab I have calculated the Vout = 4.2V and now I am ...
2
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1answer
46 views

Free spice Model to simulate integrated circuits design

I am using ltspice and I would like to simulate integrated full custom circuits for educational purpose. I found the NMOS4 and PMOS4 models but there are not enough since there are too ideal there ...
2
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2answers
78 views

General impedance converter

Can anyone give an explanation about general impedance converter? This question might not be specific enough, but I will appreciate if someone could share as much as possible about this circuit.
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1answer
98 views

Understanding source and return current flow on PCBs

I'm looking for advice and tips related to PCB board layout and signal+ground trace/track routing. I'm designing a 2-layer analog-only PCB that has several I/O signals leading to and from other ...
0
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0answers
21 views

Precise power metering for small motor

We have a system that contains a DC motor (3 W nominal power, but generally running much lower) powered through an H-bridge from a single cell Li-Ion battery (range approx. 3.0 to 4.2 V). The motor, ...
3
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3answers
96 views

Using step-up converter in metering instrument?

I am designing a pressure calibrator (my first Real project), which is supposed to measure from 0-200.00 mmWC (20000 counts) using Silabs C8051F350 (inbuilt 24-bit Sigma delta ADC). Sensor used is a ...
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2answers
68 views

Input voltage for LM4862 audio amplifier

I just started working on an embedded side project that requires me to pump .wav files through headphones. My main microcontroller is a PIC32, and my audio amplifier is an LM4862. For the DAC ...
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3answers
62 views

Turn a load on with a pulse of power, keep on until (NO) button is pressed

I have a device that sends a pulse +12V when access is confirmed. I would like to keep a relay live until a button is pressed to close the circuit. This is used to start up a cars (acc) and allow it ...
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2answers
86 views

Need an optocoupler for getting directly proportional output galvanically isolated from the DC input

I want to use an optocoupler to linearly step down a DC voltage which willy vary from 0V to 400V. That is, I want the output to be directly proportional to the input and I want it to be galvanically ...
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2answers
85 views

Simplest possible oscillator (with some constraints) [closed]

I'm interested in finding an oscillator circuit that meets the following constraints: Runs on 9 volts or less Periodicity 100-1000 Hz or so Non-sinusoidal oscillation No inductors 1 transistor or ...
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1answer
68 views

Automotive Sensor - Excessive Ripple Noise

I'm designing an automotive oil temperature sensor based around a 3-wire RTD. This is my analog circuitry: U1 and U2 provide a 1mA bias on the RTD which is measured by U3 and gained up by U4. R5, ...
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1answer
95 views

How to eliminate early effect in constant current source

When designing an differential amplifier it is important to have a precise constant current source (which I will abbreviate with CCS). It helps to keep out signal injections from the supply rails. A ...
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1answer
49 views

BJT small signal analysis, ignoring current sources

Question for you. Currently 'm in the middle of studying for an analog II exam. I've got the following midband small signal model: When analyzing for midband gain, more specifically VB2/VPi1, the ...
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4answers
76 views

sinusoidal frequency doubling

In a project I'm working on, there is a need to supply satellite navigation receiver with signal from very precise external oscillator. Device, part of which receiver is, should be able to convert ...
0
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1answer
49 views

Board or product to drive 15 PWM/analog outputs from USB/serial connection

Ok, Let me explain: I would like to drive 15 analogs (0-12V) signal from my computer (based on user interactions/other not-so-cool stuff). This hardware has to be controlled over USB or Serial port ...
2
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1answer
71 views

Lower Voltage LED organ

I am interested in adapting this Jameco kit schematic to my own needs. I have run into an issue though. I am not sure how to lower the voltage requirements. This circuit is built for 12V, I would like ...
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4answers
460 views

How can one make an analog voltage memory circuit?

I am looking for a circuit that can, on input, remember a certain voltage and output that voltage indefinitely even after the input has been taken away. The circuit should not change its output until ...
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2answers
85 views

Voltage limiter is shutting down completely when tripped

What the circuit is designed to do The following circuit is designed to accept a rectified (low frequency) sinewave input of amplitude 0-30V, and filter it through charging a capacitor until its ...
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1answer
85 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 ...
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1answer
50 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 ...
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2answers
233 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 ...
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0answers
65 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 ...
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1answer
82 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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1answer
62 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 ...
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2answers
69 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 ...
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70 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. ...
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1answer
85 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
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1answer
154 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
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2answers
238 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 ...
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1answer
76 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 ...
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95 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 ...
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3answers
113 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 ...