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Questions tagged [circuit-design]

a term to describe how a circuit should behaved based on accomplishing a particular task. When designing circuits, one should consider how it works, the target specifications, efficiency, cost effective, code compliant, and ethics.

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1answer
33 views

Kirchhoff Voltage Law in a two port network

In a tutorial about h parameters of a two port network, I find the below snippet in the image unable to grasp. According to KVL, the total voltage in a loop is the algebraic sum of the individual ...
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1answer
34 views

Adjusting the gain on a 4th Order Butterworth Bandpass fIlter gain

I designed a bandpass filter with the TI filter designer tool but I initially designed with a gain of 40 dB. However, I'd like to reduce the gain to 20dB but I'm having issues doing trying to figure ...
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0answers
35 views

How make a pulse acquisition from an electrical meter directly into a raspberry pi?

I would like to acquire pulse informations from a french electrical meter. There is a picture of the outputs of this electrical meter. These pulses vary in frequency and after acquisition, we can ...
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2answers
83 views

Is this IR LED driver circuit with a transistor OK?

I am making a custom IR array board with a custom Arduino (only ATMEGA328 and necessary components.) So please tell me will this be fine or if I need to make some changes. IR LED = 940nm, continuous ...
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2answers
75 views

Design a Circuit with Zero-Order Transfer function H(s) > 1

I know that if I do 2 1K ohm resistors in series, I can just do a voltage divider to get Vout/Vin = R2/(R1+R2) = 0.5. But if I want to get a transfer function of 3, what components would I use?
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3answers
78 views

Can someone explain this constant current load circuit?

I'm currently a rising junior in EE and I was just wondering if anyone could help explain this circuit for me. The purpose for this is because I need to learn how to build a discharger (constant ...
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2answers
70 views

Circuit to tell Microcontroller when Voltage is Low

I would like to trip an input, similar to a button input to an microcontroller if the input voltage to the circuit/microcontroller is below a certain threshold. I have transistors and some zener ...
2
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0answers
45 views

Designing an audio amplifier, problems with bandpass filter

I am trying to build a Audio amplifier for a university project, I think that most of my circuit is done but I have an issue with my filter as my sine signal is not symmetrical after filtering to ...
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0answers
27 views

How do I turn a function generator into a current controlled function generator?

I'm using a custom pulse generator with voltage controlled biphasic (both negative and positive voltage) pulse train output to stimulate a living tissue which is grounded on one side. I need to be ...
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0answers
23 views

which one is preferable encoder or decoder for optimal solution? [on hold]

while study the topic of encoder decoder in the subject of DLD my teacher ask a question that is which one gives optimal solution many of students give answered it's depend upon the circuit design but ...
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4answers
126 views

What is the purpose of using the transistor in the circuit?

Current sensor using an instrumentation amplifier: Image source: Texas Instruments INA139, INA169 High-Side Measurement Current Shunt Monitor, Typical Application Circuit (datasheet page 1) Could ...
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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
377 views

Will love to understand how the circuit works based on this schematics [closed]

Just a pure understanding of the workability of this circuit.
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1answer
46 views

Long Distance High Speed Wireless Data Transfer

What kind of device can I use to transmit data at a rate of 1MB/min up to a distance of 100 miles? If that's not possible, what's the farthest distance to which I can transmit the data.
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2answers
49 views

Exceeding voltage on STM32 Vbat pin

I want to power STM32F429 Vbat pin with an existing Lithium Ion battery on board. However, the maximum voltage on the discharging curve of this battery is 4.2v which is above the maximum operating ...
0
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1answer
43 views

5 V from power bank not constant when supply circuit

Now I'm working on my project which contains Arduino, LCD, electromagnetic lock, 6 channel 5v relay and 500V isolated converter. My project was designed to power by using a power bank. Now I use eloop ...
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2answers
62 views

Load capacitance of crystal

I know this question has been asked many times before, however this question differs in the use of an uneven set of capacitors. I'm replacing the crystal on an old computer. The original symptoms ...
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1answer
25 views

Capacitance to useful signal conversion

Working on a project, where we need to measure the change in capacitance(capacitance change roughly from 0.5 pF at the start, to 20 pF at the end of the measurement). On the variable cap, only the ...
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0answers
50 views

How to findout the value of V(s)/V(e)?

How to findout the value of V(s)/V(e)? Is it correct? $$\dfrac{Vs}{Ve} = \dfrac{\dfrac{R2 \cdot \dfrac{1}{j\omega C}}{R2 + \dfrac{1}{j\omega C}}}{R1 + \dfrac{R2 \cdot \dfrac{1}{j\omega C}}{R2 + \...
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1answer
79 views

Is this an appropriate smps design? [closed]

I am an engineering fresh graduate with an interest in PCB design. I have been learning KiCAD which is really fun and I enjoy it alot. A friend came to me with the reference circuit attached here and ...
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0answers
135 views

Could i get some circuit design feedback?

I have a computer science background and this is the first circuit I've ever designed. It is a lot of fun designing these circuits, but it also always feels like I'm missing a lot of "obvious" common ...
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2answers
60 views

Looking for reed relays for high voltage commutation

I need to chose a reed relay for connecting a point to high voltage (probably between 7000V:15000V) or to GND signals. System will have 8 channels (pins). Some of 8 pins will be connected to high ...
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0answers
35 views

Current flow on this branch [duplicate]

What happens in this current branch? In circuit analysis how to deal with branches like this?
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2answers
108 views

What is the best method for reverse voltage protection of a microcontroller

When connecting a USB to TTL cable to flash a microcontroller (ESP32), I want to provide reverse voltage protection because connecting the pins in the wrong direction is easy to do and will destroy ...
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7answers
2k views

Is it a bad idea to replace pull-up resistors with hard pull-ups?

On many of my designs, there are ICs which have mode selection or similar inputs that are permanently pulled up or down using resistors. If I replaced all these with simple hard pullups or pulldowns ...
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1answer
44 views

The proper way of using gm/Id plot for designing an amplifier or OTA

For any design of an amplifier or OTA, we are given the specs which we need to achieve including: Gain UGBW or 3db BW Slew rate Power consumption Phase Margin Load capacitance I would like to ...
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0answers
32 views

Best way to ground a pin when Power switch is closed?

I'm using a Particle Electron micrcontroller and powering it by connecting the battery through a power toggle switch. Since I also have a solar panel connected for battery charging, I need to GND the ...
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2answers
46 views

clearing out voltage of a synchronous circuit

I apologize if this has already been answered, but i can't seem to find this question anywhere, maybe because i'm not using the right terminology in searching. My understanding is that most processor ...
1
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1answer
60 views

Interfacing instrumentation amplifier

I would like to interface several LTC6915 instrumentation amplifiers with a microcontroller. I have a schematic which looks something like below image: What I figured out is that the two amplifiers ...
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1answer
100 views

Unusual behaviour between two seperate electrical circuits in a race-car

simulate this circuit – Schematic created using CircuitLab I have designed and created two systems that are currently present in a small race-car. The first one is a circuit to control the ...
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2answers
122 views

How do I design a constant current load circuit?

I'm currently a rising junior in EE and am honestly completely lost... I've been tasked with designing a constant current load circuit to discharge parts of the battery pack for Georgia Tech's solar ...
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1answer
56 views

The boolean expression from a circuit

Would the final boolean expression to the circuit be right? Or do I have to multiply the brackets b(c*d)' out to bc' + bd' simulate this circuit – Schematic created using CircuitLab Edit: My ...
-4
votes
1answer
68 views

logic gates, implementation [duplicate]

Task: Draw an AND circuit with 8 inputs, a circuit which implements the expression a∧b∧c∧d∧e∧f∧g∧h. Condition: Use only NOR-Gates with two inputs to solve this task. Could anyone give me a hint, ...
0
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1answer
58 views

Why connect a 35 V decoupling capacitor to stepper motor driver when using only a 9 V DC supply?

This circuit uses two hybrid stepper motors each connected to a stepper motor driver A4988 and powered by 9 V DC supply to the drivers' MV pins. Both motor drivers have their VDD (logic supply) pins ...
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2answers
84 views

Decoupling capacitor placements and ratings - how to choose?

I am building a circuit with 2 hybrid stepper motors each powered by a stepper motor driver A4988 and both drivers are connected to an Arduino UNO R3. Before soldering the components together on a ...
0
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4answers
111 views

How can Ohms law be used to calculate the resistor value for an LED when multiple voltage/current pairings give the same resistance?

Say I have a 9V supply, and I want to power an LED that requires 3V and 0.02A. From what I understand, I need to add a resistor that will drop 6V, and reduce the current to 0.02A, and I can calculate ...
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2answers
98 views

Trouble with engineering project - 555 timers

I'm currently finishing my GCSE engineering project and I am attempting to use a dual 555 timer circuit as a timer. I am using a schematic I copied off Kitronik Alarm Project Kit, but when simulating ...
2
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3answers
457 views

Inductor and capacitor for energy storage instead of battery

I am trying to see if it would make sense to use a LC network to store small amount of electrical energy (500 mWHr or less) as an alternate of a 3.3 V battery. What I understand is that L and C are ...
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0answers
47 views

Not understanding current direction for this specific circuit (very basic question)

For the following circuit, I am for some reason just having troubles with understanding why the current (circled blue) moves in the up direction across the capacitor. Or for example, this following ...
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2answers
58 views

LEDs sharing negative output from driver issue

I am having an issue with the above circuit when LED DRIVER B has 0 PWM and LED driver A is being driven by a signal driver B is supposed to be off but the leds from BANK B are still lit dim. I ...
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2answers
110 views

drawing a circuit, nand gates

Task: Construct an AND circuit with 8 inputs, a circuit which implements the expression a∧b∧c∧d∧e∧f∧g∧h. Condition: Use only NAND-Gates with two inputs to solve this task. Could anyone explain to me ...
2
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1answer
48 views

How to determine the best resistance for a weak signal Twin-T notch filter?

I am designing a 50/60 Hz Twin-T notch filter for a weak (biomedical) signal output from an instrument amplifier (InAmp) to be chained to another active low pass ...
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4answers
129 views

Is there a preferred order in which to apply (analog) filters in a chain?

I'm working on a project where a very weak signal need to pass through a bunch of filters. However, I am seeing quite a lot of different ways in which the order of the various filter stages are ...
4
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1answer
1k views

When do you need buffers/drivers on buses in a microprocessor design?

I was browsing Microprocessor Interfacing Techniques and found this pharagraph: The microprocessor's buses must connect to every memory and peripheral input-output chip in a system. All MOS ...
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1answer
32 views

Solve setup time violation when CLK is same as data input in shift resistor

DSTM7 is same as push button 1 and DSTM8 is same as push button 0. I want shift resister shift when either button is pushed. For example, when push button 1 is pushed and DSTM7 has a pulse and shift ...
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0answers
38 views

How to optimise this dual (bidirectional/bipolar) opamp+BJT voltage controlled LED driver?

I'm working on a dual, voltage-controlled LED driver circuit, where one LED's brightness indicates positive voltages at the input, and the other LED indicates negative voltage. The purpose of the ...
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2answers
63 views

Circuit diagram question - microcontroller input protection

I'm new to electronics, and I would like someone with more experience to look at my diagram. The circuit consists of: a 5 V regulator (from a 12 V input) that powers the microcontroller a pull-up ...
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3answers
547 views

Contradiction:Maximum Power Transfer and High resistance of load

Whenever we load a circuit, there's a drop from the open circuit voltage \$v_{oc}\$ due to the internal source resistance or Thevenin's resistance\$R_{th}\$. So we need to have an \$R_{load}\$ that ...
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1answer
66 views

Transistor latching circuit

I have made the following circuit from a few online sources, it is very basic but uses two NPN transistors to make a latching circuit that toggles when either push button goes to ground. My Falstad ...
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2answers
52 views

How protect analog input connected to thermistor through long wires

I'm developing a data acquisition board for 8 thermistors hooked up through 3 feet wires. The board is gonna be installed inside a package unit air conditioning. In there, we have compressors, fan ...