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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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23 views

Multistage Audio amplifier with gain 175 [on hold]

I need to Design the audio amplifier with following specifications . I am going to design for the first time and I don't know what sort of transistor should be used how should I start . Any tips . ...
1
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0answers
27 views

What are suggestions for designing a circular electromagnetic accelerator? [on hold]

I am currently planning to build a circular electromagnetic accelerator, think a particle accelerator that is accelerating a macro-sized projectile instead of an elementary particle. My current ...
0
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0answers
57 views

Circuit that averages voltage

Suppose we have an oscillating signal V(t) with V(t) >= 0. I'm looking for a circuit that averages this signal over a given time so that I can read out the average value directly using a simple ...
4
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1answer
119 views

Why is this component that looks like a capacitor with ground lines in this circuit diagram different from a polarized capacitor? [duplicate]

What is the component that is represented with two horizontal lines like a capacitor with three Ground Chassis lines connecting them and a + at the top and a 10μ label. See picture below (top right ...
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33 views

Finding the right multiplexer for my project?

For my project, I am cycling through IR emitters, turning them on and then off. For every emitter, I'm also cycling through all IR receivers, collecting their analog data. I want to use a multiplexer ...
0
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0answers
16 views

How to design ping pong datapath with logisim & FSM [on hold]

I am trying to design a ping pong game on logisim using state machines but i'm kinda newbie to FSM and logisim in general. I know logic(MUXes,Boolean Logic,Karnaugh map and evaluation,gates etc) ...
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0answers
30 views

Using XBOX controller as RC Car transmitter - basic circuit help [on hold]

To summarise as per moderators request: 1.Is there a better way to achieve the circuit pictured below? 2.How do I find a resistor with a value of 109ohms and a resistor 8.8Momhs for a voltage of 3....
0
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2answers
36 views

Full Adder Circuit

This circuit is based around the SN74HC283 4 bit full adder. What purpose does the resistor network serve? Will this circuit work without any resistors, i.e. using raw inputs and outputs? ...
1
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1answer
32 views

Feedback on a simple Motion activated motor circuit

I have been working on a Motion activated Motor which uses PIR sensor to detect the motion. The idea is when PIR detects user in front of it motor should start running and when the user moves away ...
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0answers
56 views

Light sensor using transistor

I am trying to create a light sensor circuit using 2N3904 transistor but current is not passing through RL what is error in my circuit?
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0answers
91 views

First PCB project design critique requested (RF) EDITED

This is my first ever RF PCB project and it'd be great to receive some guidance to make this project 'first-time-right'. It's purpose is to transmit and receive signals at two different frequencies: ...
1
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2answers
65 views

If I need to find an MOSFET spice model with a particular length and width, where do I start?

I was using a 180nm NMOS and PMOS but now need to use an NMOS with about L=.36u and W=100u. I have two models but I dont think I can just change the length and width to any value. How can I check if ...
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0answers
63 views

How do you plan and check if a device will be compatible with every other device it will encounter in the field?

Hello I have a question that hopefully I can clearly state my question well enough. I work in television broadcasting and simply take off the shelf converters that take various signals and convert ...
0
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1answer
38 views

use of the mass as in-circuit conductor

In some applications, such as dynamo-powered bicycle lights or torches (the old-fashioned ones with a metal barrel) the mass is truely integrated in the circuit. That is, the wiring does not form a ...
0
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2answers
71 views

Does connecting LEDs in parallel use more current then connecting them in series in my circuit?

Sorry if this is a dumb question, I need a sanity check on this stuff. Is it possible to give LEDs varying current, without sacrificing efficiency? Basically I have 4 LEDs which could all use ...
0
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0answers
44 views

Monitor a phone line but appear to be on-hook?

I'm having trouble debugging a program. The program opens the modem and watches for Caller Id. If a name or number is in the FTC Do Not Call (DNC) Reported Calls Data database then I go off-hook, ...
5
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2answers
124 views

How are instrumentation amplifiers constructed on the semiconductor level?

I'm curious as to exactly how in-amps are designed at a transistor level. They're often shown as being made of three op amps, but due to how specifically the amplifiers are being used I expect that ...
1
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3answers
74 views

How to replace relay with N-Channel Mosfet

I have this simple circuit which uses a relay to charge and discharge a capacitor. Now instead of a mechanical switch, I want to use an electronic switch such as a N-Channel Mosfet. How can I ...
0
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1answer
43 views

LED switching: Circuit reacts unexpected

I have my current circuit in LTspice and am trying to simulate it. The idea is the following: I have a UV LED (360 nm) which I want to switch off in at most 6ns. For this I have my LED in parallel ...
1
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1answer
37 views

Back up power supply for microcontroller and servos

I currently have a simple circuit which lets me control a servo using an arduino and have everything working, but I need the servo to go back to the default position in the event of a power failure, ...
0
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1answer
53 views

RF Design / Calculations - 433.92MHz, PCB antenna, values of capacitors

I'm doing a RF remote control project using a PCB with microcontroller and with simple onboard antenna layout as transmitter and a 433.92MHz receiver RWS-371F-6 model. Here is the datasheet of the ...
0
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1answer
16 views

Wiring a TCST2103

Any TCST2103 (optical sensor) module I bought is wired so the signal is HIGH when triggered and I need the direct opposite. Tried to find a place in the module to match the opposite voltage, but seems ...
3
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2answers
889 views

Test pad's ESD protection

I design a module with onboard test-pads. I put ESD protections to all out-world connections like sockets etc. But I want to ask that; should I put ESD protections to test-pads and ISP socket inputs?...
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0answers
83 views

Problem with PCB making

I have followed a process to make a PCB, whose link is given below. I have followed the every process as mentioned with correct proportion of chemicals. But, unfortunately, this didn't work (traces ...
0
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1answer
55 views

Trying to have NMOSs in parallel while passing current through only one at a time

If I wanted to have a bias current I1 going through M1 or M2 and I want M1 to alternate between on off (M1 on/M2 off, M1 off/M2 on) would this work? I simulated this with spice and for the first ...
1
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0answers
54 views

Current splitting in nA,pA range till 100 kHz frequencies

This relates to my previous question of current splitting. Current splitter/divider in nA/pA range possibilities I read about some circuits on current copying (current conveyor). However, the ...
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0answers
58 views

Do photodiodes break KVL?

I know what you are thinking, but hear me out. Let's do KVL in this loop: simulate this circuit – Schematic created using CircuitLab We get: $$ -V_{PD}+I(R_s+R_L)-V_1 = 0 $$ Now we solve for ...
0
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1answer
95 views

Current splitter/divider in nA/pA range possibilities

My objective is to realize a current splitter which could split current from a wire A in the range of pA, nA equally to wire B,C. I was initially sure what this type of circuit would be called, but ...
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0answers
20 views

What is the voltage across a photodiode bellow the Saturation Limit?

This is the equivalent circuit for a real photodiode: simulate this circuit – Schematic created using CircuitLab Source. I added a Bias Voltage based on Figure 1-9 (a) of the Opto-...
0
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0answers
8 views

2 fuse wonder, should they work as one? [migrated]

I have a circuit with 2 15 amp breakers. They don’t act, individually they both have to be such off to shut off the circuits. Am I looking for an outlet with two devices? Example switch and outlet?
0
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3answers
51 views

Minimizing reflection coefficient of a low-pass filter

I'm trying to figure out (with not a lot of success) as to what I need to consider when I want to minimize reflection coefficient below a certain point. I'm trying to design a low-pass shunt stub ...
0
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1answer
31 views

How to measure load detection for ballast output 18W

I have a high performance ballast of only 18W and 36W. I would like to do a detection circuit whenever the UV light tube does not have any light out, an alarm/signal can be triggered to replace the ...
0
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2answers
59 views

How are capacitor voltage ratings chosen

I'm reading a user document of a dev board. On page 12, there is an explanation of the power management subsystem. The board VBUS and VBAT lines have a decoupling cap rated at 6.3V, whereas the output ...
0
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1answer
44 views

how to make different grounding

yesterday when i ask about driving circuit, someone told me that it is a little use in optocoupler when i use the same ground everywhere. because so far (iam a green hand in electronic) i just connect ...
0
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1answer
112 views

DC-DC Buck Converter Issue

I made the below discrete two transistor buck converter. When NO load the output shows 5V nicely. Even a small 100mA load, the output voltage drops down. How to overcome the issue? Actually I need ...
0
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0answers
8 views

spectre save command - usage

I did look at save command documentation in Spectre user and reference guide. But it still looks confusing to me. I am specifically looking for commands to do following two task: 1) probe all nodes ...
0
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0answers
30 views

Wanted low cost impulse generator for TDR tests of short distances

In this video: https://www.youtube.com/watch?v=9cP6w2odGUc A simple cheap circuit is described to get 2nS rise times for use in ringing cables for a TDR test. I started thinking that there might be ...
1
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1answer
44 views

In this semi-ideal photodiode, what would be the physical interpretation of this current?

A real photodiode can be expressed as a circuit made of several ideal components, it looks something like this: simulate this circuit – Schematic created using CircuitLab I copied it from here ...
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0answers
38 views

phase shift oscillator circuit

I'm planning to construct a phase shift oscillator circuit. I simulated it using multisim and i got the sine wave with values I wanned (you can check the pic). then i assembled the circuit on a ...
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0answers
28 views

How to detect source presence using LTC4412?

I'm using 2 power sources as shown in below picture. The status pin is suggested to pull HIGH to VCC(which can be the adapter input). As mentioned that Status pin OUTPUT is LOW when Wall adapter ...
8
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2answers
2k views

Need help with a circuit diagram where the motor does not seem to have any connection to ground. Error with diagram? Or am i missing something?

I'm following a really simple electronics instructable found in this link: https://www.instructables.com/id/Vibrating-Timekeeper/. I've been studying the circuit provided but can't figure out why ...
2
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0answers
53 views

D-Class Amplifier Design Verification

I have an internship coming up working with comparators and amplifiers, so I wanted to take on a side project involving both of those components. Designing a D-Class amplifier seemed like a great way ...
0
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2answers
80 views

Circuitry to measure sub-nano ampere current [duplicate]

Is there a well known methodology to design a IC circuitry to measure sub-nano ampere or even pico ampere currents within a very short delay of nano seconds? The SNR could be assumed to be fairly good ...
0
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0answers
58 views

Headphone Jack Detection Mechanism?

I am trying to build a circuit that turns on a speaker when headphones are unplugged (so it like how our phones detect when our headphones are connected). To do this, I was thinking of simply using ...
1
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0answers
43 views

Snubber for Relay Contact Switching Resistive Load

I am working on a redesign of some circuit boards and am looking for a way to save space and potentially switch to surface mount parts. Some of the largest through hole parts in use are for an RC ...
0
votes
1answer
53 views

Circuit with a single buzzer but multiple L.E.D and switches

I need to design a circuit that has three LEDs, each LED has its own push button switch, but there is only one common buzzer. Goal: when a push button is pressed its corresponding LED should glow ...
0
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1answer
39 views

Simple Circuit: light source seperated from signal source?

Forgive me for the simple question! How would I create a circuit for a light that is switched on when another light is switched on? Basically I want to use a more powerful source for a new light ...
0
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1answer
48 views

Use of internal PCB ground plane as ESD baseplate/EMC reference plane of product in plastic enclosure

I am designing an electronic product which will be housed in a plastic (non-conductive) enclosure. There are a number of, mostly shielded, I/O cables (Copper 10/100/1000Mb/s Ethernet, USB 2.0, RS232, ...
5
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3answers
5k views

How do I measure a voltage greater than 5 V with Arduino? [duplicate]

I want to measure a varying voltage with an Arduino and real time data plotting has to be done. But the supply voltage will be 10 V and the Arduino is not supposed to have more than 5 V. Is there a ...
2
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1answer
51 views

Electrical circuit design questions [closed]

So I was wondering if there is any site or papers that has fun electrical circuit questions, such as placing the right components on a circuit to make it work, make the light dimmer/brighter by using ...