Questions tagged [analog]
Analog circuits have a range of voltages, rather than just two as in digital logic.
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2answers
37 views
Increasing drain current, decreases common-mode level
The basic idea behind the CMFB setup is that increased output common-mode level feeds back into the gate-source of the triode devices and causes drain current to increase and hence output CM level to ...
1
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1answer
36 views
Multiple Analog input for one channel ADC with Amplifier drivers?
I have a concept of using a one channel ADC for three differents analog inputs sources.
My question is: should I worry if the the analog inputs have differents inputs impedance, one is very high ...
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2answers
71 views
How to calculate the voltage divider resistor for transistor?
How do I calculate the voltage divider resistors (R1 & R2?)
I have found that the relay resistance is 1150 ohm.
Ic = 20.8 mA, hfe = 290, Ib = 71 µA.
I'm using a BC847b transistor. The ...
2
votes
2answers
69 views
Using a capacitor instead of inductor in a switching regulator, and viceversa
Contextualizing more:
In a switching topology, and I am butchering it now, the inductor gets "charged", and eventually will keep an amount of energy "just enough" required for the load. This is ...
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1answer
46 views
Inverting OP AMP SLEW RATE
I'm trying to do a question that requires me to design an inverting op-amp in multisim and find the slew rates in different scenarios using the OPAMP_5T_VIRTUAL operational amplifier model found in ...
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1answer
52 views
Digital transmission of composite video [closed]
As the tittle suggest, I was thinking about making a wireless composite video transmission between a small camera (such as those sold for flying fpv) and a receiver. The two main specs it must have is ...
1
vote
1answer
48 views
Feedback Circuit schematic to Control Theory block diagram?
I'm studying analog electronics circuit with feedback.
I see that, during analysis, a useful abstraction over the schematic is the block diagram in control theory style, but I stuggle in deriving it ...
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0answers
17 views
Piezo position sensing [closed]
I'm wanting to develop a MIDI drum pad using 4 piezo sensors, what methods/algorithms are available to detect the locate the origin or the vibration?
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0answers
56 views
What are the Ai-Thinker ESP32-CAM's analog pins?
I am a hobbyist and nowadays I am playing with Ai-Thinker ESP32-CAM. I decided to make battery powered stream cam. So I want to measure battery level. And I need analog pin to measure it. But I could ...
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1answer
47 views
Single MOSFET current source (JFET like)
Is it possible to build MOSFET current source similar to JFET current source like this:
simulate this circuit – Schematic created using CircuitLab
With MOSFET it should be something like this:
...
4
votes
2answers
568 views
What makes “quality” analog AV cables better than cheap cables? [closed]
I want to upgrade my retro game setup from a mix of composite and RF to a mix of S-video and component, with some composite for the really old stuff that doesn't support S-video. How can I distinguish ...
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0answers
29 views
ADC Measurement on Automotive Circuit with Arm MCU
I'm trying to develop a circuit capable of measuring voltage on 6 different automotive pins at 12V nominal. I'm hoping to use the integrated SAADC in the nRF52832. I've done some research into ...
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1answer
28 views
Signal conditioning for 2SMPP-03 Pressure sensor
I am wanting to develop a circuit that accurately measures 15 Omron 2SMPP-03 sensors within its full range of -50KPA to 50KPA. Could someone give me a head start or refer me to some information on how ...
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2answers
48 views
Resources on Noise Circuits
Back when I was taking an RFIC design course, I was pretty disappointed by the noise part of the class, specifically calculating the output-referred noise voltage, noise figure of an amplifier, etc. ...
2
votes
1answer
35 views
What is the difference between differential rail-to-rail, push-pull rail-to-rail and rail-to-rail OPAMPs
I'm loking for an rail-to-rail OPAMP to my project. I need a OPAMP that fed by a 12V and a -5V power supplies can generate an output voltage near these values, at least, near the positive 12V, the ...
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0answers
25 views
Wire shield when using connector for strain gauge sensor
I have made strain gauge sensor with 1 strain gauge. Thet gauge is in "bottom" part of Wheatstone brigde (one strain gauge terminal is signal, second is connected to ground).
I'm using Sommer CICADA ...
0
votes
1answer
26 views
“Cross simulation” between analog and digital
I was interviewing for an analog/digital design engineering team and the guy said that my first task on the job will be to run cross (or crossing) simulation between analog and digital section, what ...
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1answer
67 views
Hardware specification terminology
I have a hardware specification document of a product attached below.
I am able to understand the following parameters:
Input voltage - This is defined for the range of input voltage
Resolution - ...
1
vote
2answers
32 views
Explain how this astable chain(?) circuit works
The circuit below fades on and off a cascading series of leds in an alternating fashion.
I tried reproducing it on a breadboard with 5 leds to try to understand it how it works, and got all sorts of ...
-3
votes
1answer
71 views
Working region of NPN BJT
I have come across the following circuit where a BJT works as switch when I apply 23 volts to base using a 100k resistor.
A 3.2 mA constant current source is connected to the collector of the BJT ...
1
vote
2answers
90 views
Negative Voltage Converter
I need to generate a negative voltage of approximately -12V from a 12V power supply. I read about ICL7660A that performs supply voltage conversions from positive to negative for an input range of +1....
0
votes
2answers
84 views
modify schematic to work at 5V (solar panel sun tracking system)
I have this schematic and I want to know:
if it will work at 5V (my solar panel is 5V-6V)
modifications required to command (clockwise/anticlockwise rotation) the motor directly with the final ...
1
vote
1answer
33 views
Function of RC circuit in a bistable multivibrator using op-amp
What is the purpose of the RC circuit in a bistable multivibrator?
Can't we obtain the same result, if the trigger input is supplied directly (bypassing the RC circuit)?
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1answer
105 views
Whats the cheapest protection circuit for this test equipment?
I am designing a piece of test equipment that has a DAC output. The test equipment might be used to troubleshoot UUTs that are damaged or malfunctioning. Therefore I want to add a protection circuit ...
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0answers
40 views
Line level audio output from headphones level output
I am new to analog audio interface design. I am trying to get a line level output from a amplified headphones level output. I want both of the output to work at the same time in order for the user to ...
0
votes
1answer
51 views
Changing the full scale deflection of an analogue volt meter
I've bought an old pocket style (think of an old pocket watch) analogue volt meter and the full scale reading is 6V.
I would like to change this to 3V, however I have opened it up and there is no (...
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1answer
67 views
Transfer Function of an Op-Amp Circuit
This circuit looks like an active high pass filter but without a second series resistor.
What is it really?
What is the transfer function Vo/Vi?
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2answers
86 views
Calculating base-emitter current of a BJT, with emitter connected to ground (no resistor)
Much like the circuit above, most BJT amplifiers use an emitter degeneration resistor to stabilise the bias. It's relatively straightforward to calculate the base and collector quiescent currents. I ...
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0answers
32 views
Gain and output impedance in a differential amplifier
When looking at a differential amplifier:
Why does gain increase when the output impedance is increased?
For example, replacing a differential amplifier biased with resistors for an active load (...
1
vote
1answer
85 views
Best practice on providing AVdd and DVdd from single source
I generally work in a purely digital world, however I'm working on a design at the moment that requires a separate power supply for analogue and digital components. What's the best practice from ...
1
vote
2answers
83 views
Electric field near dynamic loudspeaker at resonant frequency
Background
I am driving a cheapo 8 Ohm speaker with an LM386. The LM386 circuit is nearly identical to the one in the datasheet shown below, except Vin is AC coupled through a 10uF capacitor and the ...
2
votes
3answers
133 views
Potentiostat Drift
Firstly - First post so let me know if I have done anything wrong.
Okay, so I am tying to get this biased potentiostat to work. I have attached the circuit below. I am using the following sensor:
...
0
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0answers
46 views
I have two inputs which are switching between 12V and a GND. I want to have a wire where I always have 12V and one with where I always have GND
As in the title.
Assumptions :
The inputs are switching at the same time.
If one is 12V the other is GND and vice versa.
I have tried coming with a solution on my own : using an OR port (diodes) to ...
8
votes
1answer
176 views
Can anyone explain the point of this dual PNP/NPN set?
I like to consider myself fairly experienced in Electronics Design, but upon being contracted to review this schematic I'm a little stumped. This is basically the output stage of a boost power supply:
...
1
vote
1answer
45 views
PTC thermister value
I am trying to find out specifications of a thermister on which "10P" is printed. Its resistance at room temp. is 18 Ohms when the circuit is power off. How can I find out its specifications?
This is ...
3
votes
0answers
30 views
MOSFET pinchoff reduce current
I understand that in an n channel MOSFET as Vgs increases, electrons are attracted towards the gate forming an n channel. These electrons are responsible for the conduction of the MOSFET. As Vds ...
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0answers
24 views
Reading analog signal of metal detector using arduino
I would like to tap into analog signal of Garrett AT MAX metal detector (ínfo) and read the value using arduino analog in. Schematics for the metal detector can be found here
It seems to me that the ...
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0answers
47 views
What is maximum symmetrical output voltage swing in this case?
I'm pretty new to Electronics and hence the following doubt. I could not understand how the authors reasoned out the swing limits for this problem ((b)-part only)
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1answer
31 views
SIMPLE digital control over 555 timer frequency and PWM?
I'm looking to create a sound generator with only simple ICs and components. I believe the 555 timer IC is a good candidate to be at the core of it, but I cannot for the life of me find out how best ...
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2answers
47 views
Metal detection with a coil matrix
I have an 8 x 8 grid and would like to detect where on the grid I place a metal object. I'm currently working with the TDA0161 metal detection IC, and so far have the following setup with detection ...
7
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1answer
679 views
What kind of display is this?
While investigating analog technologies I discovered these images of a quadraphonic 8-track player. All 8-track players I've seen before use analog voltmeters as displays rather than square graphical ...
1
vote
1answer
51 views
Sinusoidal voltage source not being sinusoidal in LTSpice
I'm trying to obtain the output resistance (resistance from collector node) of the following circuit
By inspection, it should be the output resistance of a common emitter amplifier with degeneration
...
1
vote
1answer
105 views
When to use analog PID
So I am building a rather simple constant current load to test power supplies. I am using an INA138 for high-side current measurement with only 5V power (and I have reasons for that, unfortunately) ...
1
vote
1answer
176 views
What's the catch with these JFETs?
I'm designing a low-noise, high-bandwidth (100 MHz) pre-amp using JFETs. The choice for JFETs was because it needs to operate with large source impedances (>10 kΩ).
I spent a while looking for a ...
0
votes
1answer
43 views
Does direct GPIO communication between 2 microcontrollers requires pull up/down
If I want to use GPIO pins of two microcontrolles as a mean of simple communication (e.g. reporting an event by sending 1 or 0), Do I need to enable internal pull up or pull down resistors on any of ...
0
votes
1answer
46 views
VHS(C) tape speed issues - how does the speed change for different modes?
I have a VHS-C camcorder that has a lot of trouble keeping constant speed for the main tape motor (even with the battery fully charged). Most of the time it's way too fast (similar to fast forwarding),...
5
votes
2answers
1k views
Can a zener diode with a higher power dissipation be used in place of the original one in an audio amplifier?
Following my Marantz PM-68 repair question, I would like to change a faulty zener diode used in the amplification stage.
I don't really understand the purpose of this diode but I guess it's used for ...
0
votes
1answer
32 views
CMOS switch with “negative” current
In a project, I need to swap the polarity of a 12V power/signal and GND wire combination electronically.
The current flow is between 7 and 28 mA.
I'm using a DPDT relay for this - the input wires are ...
2
votes
2answers
205 views
Device to loopback mic to headphones
I have an issue with my headset. I can’t stand not being able to hear myself speak. I’d like to build a passive device to loopback the mic to the headphones that would be plugged in-line between the ...
1
vote
2answers
47 views
vestigial sideband modulation [closed]
If we are given the following equation of Vestigial Side-band Modulation, what values will I put in the equation?
$$ H_0(f)=\frac{1}{H_i(f+f_c)+H_i(f-f_c)} $$
