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Questions tagged [design]

The process of creating electronic products, including components and end-user devices.

0
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2answers
39 views

Alternative to alternating relay? or help?

I'm using a littelfuse relay shown in the link to switch motor directions. I'm sending a pulse to the relay switch of 0.02s in order to switch between the L1 and L2 contacts. The pulse seems to be too ...
0
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1answer
35 views

Help needed for HV DC/DC converter

I need to design a boost converter that outputs ~20 mA DC and an unloaded voltage of around 68-100 V. The inverter will be part of a Zener diode analyzer. I built it on the idea of the Joule thief (...
1
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4answers
99 views

Circuit to convert 24VAC digital signal to 5V DC digital signal

I am designing a circuit to convert 24VAC signal to 5V DC signal. The 24VAC signal is designed where 24VAC is on and 0VAC is off. The signal needs to be fed to an MCU which is 5V DC. The circuit ...
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0answers
21 views

Graphene yarn used in stator design [on hold]

Can a current be induced in graphene yarn if used in a stator to replace the copper windings?
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1answer
90 views

Designing a RAM, using 4x2 chips, with a 8 address capacity

This is a typical exam question, and I've seen some very helpful posts about, but I still have a lot of doubts. Given an integrated circuit of certain dimensions, for this example a 4x2, I have to ...
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2answers
113 views

First pcb design is it safe?

I have designed a pcb board (2 layer) that deals with high voltage 220VAC and it also converts it to 5VDC and 3.3VDC. So, because it is my first design and I deal with high voltage I want to be sure ...
1
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1answer
38 views

LED current source circuit design concerns

TL;DR: Read the bulleted list below. I am designing a simple constant current source to power up some LEDs inside arcade buttons. My project consists of 20 of these buttons. Every button is ...
0
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0answers
40 views

JFET Voltage Divider design question

I've been trying to get this question done for a couple of days now and no matter how much I try I've been unable to get it done. Your help in this question is greatly appreciated.
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0answers
12 views

What is sthe difference between acoustic photon and acoustic phonon? [migrated]

In the book Biomedical Photonics Handbook, 3 Volume Set edited by Tuan Vo-Dinh, it is written : Brillouin Scattering is caused by the interaction of the photon with the acoustic phonon. As the result ...
6
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4answers
1k views

MOSFET W/L ratio limits: what's (un)reasonable?

The answer to this question is probably process-dependent, but what are the limits of the W/L (gate width/gate length) ratio for MOSFETs? I don't know what is in the realm of the insane. I saw a ...
0
votes
1answer
60 views

What to do with unused pins for this ADC?

For my senior design project I'm using this ADC (HMCAD1511) https://www.analog.com/media/en/technical-documentation/data-sheets/hmcad1511.pdf I'm only using one of its four analog inputs - what ...
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votes
3answers
68 views

PCB Trace Widths? [duplicate]

I am designing a circuit board using proteus 8.1 , does anyone know how to calculate trace widths for the PCB tracks , it may need to handle a high current so it’s important this is all calculated , ...
4
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2answers
138 views

What step have I missed designing this differential amplifier?

First time posting on EE.SE and I hope this question isn't too broad. This will be a long post. I should also point out: I'm asking the process and not the solution the problem. I've did create a ...
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1answer
90 views

I have a college senior design question [closed]

I'm in my second to last year of mechanical engineering. So next year I'm going to be going into senior design. For those that have gone into any engineering course and have done senior design ...
1
vote
3answers
57 views

Single Cell Battery Protection ICs

I'm designing a product that will be powered by a single 18650 cell. Specifically, I am basing my numbers off this cell in particular: Samsung INR18650-25R It has a typical full voltage of 4.2V ...
3
votes
1answer
98 views

What determines Nixie tube digit stack order?

I recently watched a video of Nixie tubes being built and another user had asked what determines the stack order of the digits in front of the anode. I searched around trying to find the answer but I ...
0
votes
1answer
37 views

Low power design, choosing correct buck-boost converter for LiPo battery

I want your opinion on subject considering low power applications. I want to build basic loraWan tracker with Murata Lora module(3V3), and I want to use LiPo battery. What Im struggling with is power ...
3
votes
3answers
182 views

How to provide version numbers to hardware schematics / PCBs?

I have one hardware design developed for a customer. We are also selling the same for some more customers with small modifications I would like to know how to provide version numbers for these ...
-5
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1answer
128 views

verilog code for 2bit * 2bit multiplier [closed]

There will be two 2 bit inputs (0 to 3 in binary), binary multiplication is to be done on these inputs, the output should be a 4-bit binary number, this output will be fed to a 7 segment display on an ...
1
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2answers
114 views

Advice for 25-50 Mbit SPI lines - PCB design

I would like to ask some advice for my layout design. I am working on a layout design. The designed PCB will be a Beaglebone Black (BBB) extension card. It is a four layer PCB with the following ...
1
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0answers
60 views

What do TA, TG and M mean on the scheme?

I have a electrical scheme but I can't get what do TA, TG and M mean? Can anyone explain me? P.S. I am a programmer, not an electrical engineer, so maybe it's a trivial question.
1
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0answers
32 views

Are GX12 connectors in common use? Is there another name for them?

I have a project where I need to send NeoPixel data from an RPI "base station" to a neopixel art project. Both the base station and the art project are enclosed already. Length is short, just a few ...
0
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0answers
21 views

Positive current source into negative supply

I am trying to use an LM334 as a constant current source on a power supply output. Because I want to have true zero output, and the LM334 operates at Vmin of ~1V, I want to put a TC7660 charge pump ...
0
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0answers
56 views

What would be an appropriate oscillator crystal for an STM32F042C6T6 given the following circuit?

I am building the circuit for a CAN interface for Linux following the schematics for the CANalyze hardware. I have sourced every component for the build except the crystal oscillator. The schematic ...
2
votes
1answer
120 views

Reasons for choosing a transistor instead of an op-amp as a buffer

I have often seen circuits for guitar pedals that use an emitter-follower configuration as the input and output buffer (see example below). If an op-amp can provide a greater input impedance / lower ...
1
vote
1answer
52 views

How to optimze a coil for needed voltage?

Faraday's law for a coil is : V = A * M * N Where: V = Peak output-voltage A = Area of the cross-section of the wire M = Rate of change of magnetic flux in the coil N = Number of turns of the ...
1
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0answers
18 views

CST Studio Space State Matrices

I am new to using CST Studio and I am trying to figure out how to see the state space matrices (A,B,C,D) of a designed antenna to describe its radiation pattern in other software. Any help on the ...
6
votes
3answers
2k views

Is it ever bad to run an IC VCC trace next to a ground plane with 1mm clearance?

Since my last board flopped, I looked at it again and noticed a ground loop (because the DB9 casing completed the loop). Now I adjusted my board so that there is no loop of any kind. Instead, I'm ...
0
votes
2answers
141 views

Is this speaker crossover design correct?

This is the schematic for 2-way crossover, the speakers I want to use are: Woofer: https://thomann.de/pl/harley_benton_15tb065_b4.htm?o=2&search=1537173360 Tweeter: https://thomann.de/pl/...
0
votes
1answer
83 views

Horn antenna for radar sensor

I have InnoSenT SMR-314 and SMR-334 radar sensors that have quite wide horizontal radiation pattern of over 100 degrees (see datasheet on page 3). I would like to make the sensors far more directional ...
5
votes
1answer
141 views

Flat Yagi antenna Enclosure

So, I was annoyed that my Yagi antenna was enclosed in a plastic-tube, which lets it roll around and fall off the table occasionally, but without its enclosure the elements hooked in anywhere. So I ...
0
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0answers
194 views

Using a comparator in tinkerCAD circuits

For anyone familiar with the TinkerCAD circuit design tool I am trying to create a simple circuit for an 'LED chaser' pattern (this is what I have seen it called elsewhere). In order to create this ...
3
votes
1answer
128 views

Why build very similar diesel-electric engines in both AC and DC traction versions?

I'm reading Wikipedia on GE Evolution Series diesel-electric engines. The series includes ES44AC and ES44DC models. Looks like they are very similar but one uses AC traction and another uses DC ...
16
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5answers
2k views

Possibilities for allocating memory for modular firmware design in C

modular approaches are pretty handy in general (portable and clean), so I try to program modules as independent of any other modules as possible. Most of my approaches are based on a struct that ...
1
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3answers
106 views

How to turn on/off a converter using OpAmps

I am designing a controller board for turning a DC/DC Converter on when the voltage level is below 24, and turn it off when it's above 29. With this circuitry I'll be turning it off above 29V. I can ...
0
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0answers
85 views

Is it possible to find out current consumption of circuit design before giving it for manufacturing?

I want to measure the current consumption of my PCB design before giving it to PCB manufacturing. Is it possible..? If yes than what are the tools..?
1
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1answer
113 views

UART pins interfacing with Barcode without handshaking signals

I am concerned about bar code interface with LPC1768/LPC1769 controller.. If I use only UART-TX, UART-RX, GND pin of controller only to interface with barcode scanner module which has UART or RS232 ...
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2answers
168 views

KiCAD How can I install every library in existence? [closed]

I'm trying to learn KiCAD and it seems that every 5 minutes I cannot find a component and substitute a different one (e.g. substitute lm317 for a lm338) This works all right in the schematic part but ...
2
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3answers
118 views

How do I power a device with a 4-directional 4-pin connector? I have an idea and I would like you to point out what's wrong with it

Let's say I have a matrix of square 12.7 mm cells. Every cell is a connector to which an independent little piece ("little piece" is a building block) may be connected. Actually, it's a little puzzle/...
1
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0answers
86 views

Are there commonly used equations for short-term overpower of wirewound resistors?

If I have a wirewound resistor rated for 250 W that might need to dissipate, say, 400 W for several seconds, is there a commonly used equation for finding its temperature rise or time to failure under ...
0
votes
2answers
65 views

Custom Tab-Shaped Plug

I'm designing a device that plugs into a base and am looking for clip-like part that will take a metal tab and transfer a small current (5V) to an LED in the device. The user should be able to pull ...
0
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0answers
51 views

How to design inductor for non-isolated boost converter?

I am trying to design an inductor of 500uH for non-isolated boost converter from following data. Input voltage Vin=330V DC, Maximum duty ratio Dmax=63%, Switching frequency Fsw=30kHz, Saturation flux ...
1
vote
1answer
55 views

Current to voltage converter with signal at non inverting terminal

I'm studying the following current to voltage converter: The output should be: $$V_{ADC2}=-Z \, I_Z - V_{WE2}$$ with \$Z=\frac{R}{RCs+1}\$. Why there is the input \$V_{WE2}\$? What is its role? ...
0
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0answers
13 views

Segmented Display With SMD Pads? (Not Thru-Hole or Half-hole SMD) [duplicate]

I'm looking through a product design, and I've seen these SMD / sticky segmented displays LCD being used. They are not hand-soldered, the segmented display appears to use some conductive sticky pad ...
1
vote
1answer
120 views

Capacitive fluid level sensor design and insulation

This is a question regarding the measurement of a fluid level (in my case water) using a capacitive sensor. Capacitive sensors are a common topic, but I have one specific question: It is necessary for ...
1
vote
1answer
27 views

Can I estimate what CPLD I need?

I'm planning to design a driver for VGA connectors, and for testing purposes I have an evaluation board of one CPLD. Concretely, the board is the Digilent's CoolRunner-II with the Xilinx's XC2C256 ...
0
votes
1answer
24 views

DC motor selection criteria: number of poles

I’m designing a system to measure an arbitrary motor torque curve. As an active load, I’m searching for a brushed DC motor that is able to withstand some degree of torque and speed as well as comply ...
0
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1answer
41 views

ADC Circuit Review

I'm building a PCB centered around an AD7608 (datasheet) with an ADG714 octal switch (datasheet) to minimize the number of wires required. I seem to be having sporadic problems (e.g. odd levels on ...
7
votes
2answers
602 views

Choose MCU with long life cycle [duplicate]

Given specific requirements one usually has a very wide choice of matching microcontrollers. Other than avoiding tags like "not for new designs" and such, is there anything one can do to ensure that ...
1
vote
1answer
124 views

STM32F103C8T6 custom design check

Following the failure of my first board design, I designed the following STM32F103C8T6 board. I only routed the fundamental parts of the board(MCU,caps, crystal, regulator etc.) This is a 2-layer ...