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

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4
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3answers
64 views

Is circuit design based on min/max values good practice?

Time and again I am arguing with a colleague of mine about the question above. When I design a circuit for mass production (> 10k/a) I want to make it robust against every possible variation of ...
0
votes
0answers
40 views

Static electricity motion sensor

Is it possible to make an efficient motion sensor using only transistors?I tried this with a couple of NPN and PNP transistors and then with a MOFSET .When someone walked by , a LED would turn on , ...
1
vote
3answers
73 views

Capacitor voltage influence

I have edited the question to make it easier to explain what I am asking for.To make it clear , I have deleted the part with the 555 timer. I have a question regarding the following : I know that ...
-4
votes
0answers
29 views

Design of Six phase induction motor [on hold]

I want to design Six phase induction motor using Finite element analysis (FEA), here i have to use ansys maxwell software. my question is how can i start also for from which particular section ?
3
votes
1answer
58 views

Splitting a big Power Trace to several smaller

I would ask if i can layout a big trace and split it into many smaller ones (see attachement) I need to run a trace capable of handling ~5A. But the trace would be too thick to fit between the pins ...
0
votes
1answer
54 views

How to restrain this soft latching power switch from eating too much current?

I am designing a two buttons soft latching power switch for a project involving a raspberry pi, li-ion cells I salvaged from the battery of a broken laptop, and a power booster from adafruit. I ...
0
votes
0answers
40 views

Adding a regulating circuit to supply 3.3v

Background I wish to power my circuit with a 18680 battery. My circuit actually has two parts: 1) a 18650 charger and power booster for USB at 5V, and 2) a Bluetooth LE module (running at 3.3v with ...
0
votes
0answers
26 views

How to design DC- DC converter in matlab [closed]

I am doing my project where i need to analyze the dc dc converter for an photovoltaic system. what are the way in which i need to analyze and need to do mathematical modelling and prove in mat lab. ...
0
votes
1answer
29 views

Altium de-highlighting nets after using 'Find Similar Objects…' command

I can't work out why Altium is doing this, or how to undo it, or how to make it stop doing it. It happens when I use the 'Find Similar Objects... ' option; all of objects that it hasn't found are ...
3
votes
2answers
48 views

Need help modifying a motion detector circuit

I'm working with my son on a 4-H project, and we have great ambitions, but very limited knowledge. We're looking to use a motion detector to switch off the current to electromagnets that will hold ...
0
votes
1answer
60 views

How do I design 5-to-32 decoder using 2-to-4 decoder?

As there are 32 outputs in 5-to-32 decoder so I will have to use 32/4 = 8, 2-to-4 decoder. But then I have total 16 inputs. As I want to create 5-to-32 decoder so I need only 5 inputs, what do I do ...
4
votes
2answers
70 views

Design question regarding high current wires running below PCB

I am working on a layout that will look similar (not final) to the illustration below. There are three high gauge wires (red) 3x230VAC passing directly below the PCB (isolation touching the PCB) that ...
-4
votes
0answers
67 views

Analog Circuit Design

I posted this yesterday and it was deleted so first of all, let me apologize if i gave the impression that i was trying to get you guys to do my homework for me. i most certainly wasn't (sorry I'm ...
3
votes
2answers
337 views

Complexity vs Space in Schematic

I got a screw terminal with the following pin configuration: ...
0
votes
0answers
42 views

Help Designing Microcontroller 2xRj45 (RS232) + 1USB-Serial

I am trying to design a microcontroller that will have 2xRS-232 RJ45 ports (not PoE, just serial communication) and a 1xUSB Type B female (for 5V power and programming). I am not exactly sure, but ...
2
votes
2answers
234 views

In a 74HC14 Schmitt trigger IC, unused inputs/outpus

I have a 74HC14 Schmitt trigger IC. I only use one of the I/O pairs, and everything else is not used. I understand that in TTL logic the unused the inputs should be set to either high or low to ...
3
votes
2answers
142 views

How to find a way to detect if a device was opened or not

I'm making a device which is inside an enclosure and at this point of the project it's relevant to understand if the enclosure/box was opened. I was trying to understand if I can try to figure it out ...
1
vote
1answer
73 views

Improving a processor design in VHDL

For a project at my university we have to improve the design of a processor (more specifically, the Plasma CPU. The design is generated based on a description written in VHDL. We have to identify ...
1
vote
3answers
106 views

PNP Transistor Leak

I have a problem with a circuit that should be simple but has caused me some annoying problems. Summary: I need a switch that closes when the power is off and opens when the power is on. My solution ...
0
votes
0answers
52 views

LED Matrix design in Logisim to display a count sequence

I've built quite a large circuit (at my level) that generates outputs d3, d2, d1 & d0. d3 and d2 are generated by a multiplexer / OR gates and d1 / d0 are generated by an 8-1 MUX. These outputs ...
0
votes
0answers
85 views

Tantalum Capacitors to Electrolytics Capacitors/Ceramic Capacitors

I'm trying to reduce costs from my design and one of the things that I'm thinking about is changing the Tantalum capacitors to Electrolytic ones with low ESR. P.eg. I'm applying one Tantalum ...
0
votes
1answer
102 views

D.C power supplies, regulated linear power supply question

Design giving the necessary ratings and characteristics the necessary for the transformer, bridge rectifier capacitor and regulator , a 12v , 2A regulated power supply . the available mains supply is ...
1
vote
2answers
123 views

How to design blinking LEDs circuit using analog elements only?

I want to design a circuit to blinking three LED in a row with 2 second delay for shifting/changing using analog elements only (using Resistors, Capacitors and Transistors and without Micro ...
0
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0answers
19 views

Circuit to integrate BeagleBone Black with Pressure Regulator

I am using BeagleBone Black as controller to control a proportional pressure regulator (Festo VPPM-6L-L-1-G18-0L10H-V1P-S1) which is the actuator of my project. The pressure regulator has an input ...
4
votes
2answers
134 views

Advantages of depletion mode FET devices over enhancement MOSFETs

I've grown the impression that JFETs and depletion mode MOSFETs are not used very much nowadays, especially in new designs. I know that they need different bias networks, especially as discrete ...
1
vote
3answers
171 views

How does one approach designing an amplifier using BJTs to drive an 8 ohm speaker?

For a lab class we were assigned a final project where we have to design an amplifier using BJTs, diodes, and capacitors (MOSFETs are not allowed) in order to drive an 8-ohm speaker. The requirements ...
3
votes
1answer
74 views

Where do these values come from?

Looking at an ATMEL SAM4E and I'm looking at the schematic checklist published by Atmel for the SAM4E and the schematic for the SAM4E-EK developer board. SAM4E checklist SAM4E-EK Design files ...
0
votes
2answers
108 views

Dual rail switching PSU critique

I am looking for feed back on the following power supply design. This power supply is intended to have 2 outputs: 24V @ 500mA and 32V @ 850mA. When the power supply is in standby, J1 pin 1 is @ 0V, ...
1
vote
1answer
73 views

Is my Rigowksi Coil turns calculation correct and how to calculate the sensitivity?

First, I would like to show my calculation. Please correct me if I'm wrong. Suppose the maximum induced voltage in the coil is 250mV and the current to be measured is maximum 1000 A. So, the current ...
0
votes
1answer
92 views

How to Design Arduino Voltage and Current Sensing Shield

I am trying to design an Arduino shield that measures raw voltage and current of a small refrigerator (115V, 60W). I have an Arduino Mega board. To one of the ADC inputs I have connected a (non-split) ...
3
votes
3answers
504 views

How do integrated circuit design companies create their datasheets?

Especially for something like a microprocessor. I assume the majority of information is "auto-generated" or we'd see a lot more typos and errors. A laughable scenario keeps popping into my head ...
2
votes
1answer
106 views

JFET biasing problem

I tried solving this problem, however I feel like there's something missing, I am asked to bias a N-channel JFET with using this provided data: Idss= 12 [mA] VDD= 12 [V] VP = -5 [V] VDS=VDD/2 ...
16
votes
6answers
2k views

New to PCB design - why doesn't auto placing components exist?

The circuit design software I have seen has the ability to automatically route traces etc. on a PCB. But why doesn't this software have the ability to automatically place components on a PCB say to ...
0
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0answers
39 views

Hack Quartz Clock Movement with Chronodot

I'm working on creating a clock design that will use an off the shelf Quartz Crystal Clock Movement. I know they are not all that accurate and was thinking of a way to make it more accurate. My ...
3
votes
2answers
256 views

How to create a frequency doubler circuit using only flipflops/ Digital elements?

First things first, is it even possible to scale up the frequency using only digital elements, atleast approximately? Though a frequency divider circuit can be designed very easily with flipflops. In ...
1
vote
1answer
59 views

How do you design a circuit to implement the Bipolar Line coding Technique?

Bipolar NRZ http://www.tutorialspoint.com/data_communication_computer_network/images/bipolar.jpg In this technique alternate 1's will have alternate polarities and 0's will be zero itself.
4
votes
2answers
70 views

Design Considerations for Raspberry Pi Expansion Boards

I am venturing into the space of designing expansion boards for Raspberry Pi's. I have done this for Arduino boards but RPi's are a different beast. From personal experience I have already had ...
1
vote
0answers
52 views

Critique and dos/don'ts for an H-bridge PCB design?

Honestly have no idea if this is something this site was made for, but I have a couple of questions about my design, mainly it comes down to "Will it work?" and "Why would it break?". JC1 and JC2 are ...
3
votes
1answer
146 views

Sequential Traffic Light Controller

Just for clarification: I'm just looking to see if I'm on the right path for this project and to figure out what the best plan of attack might be. I'm trying to simulate a sequential traffic ...
0
votes
2answers
395 views

Designing an 8 x 3 memory chip given 2 4 x 3 chips

I'm working on a problem that asks me to design an 8 x 3 memory chip given 2 4 x 3 memory chips. I'm not sure how to approach this problem. I've looked at the textbook and found various online ...
1
vote
1answer
297 views

Micro and Nano Memory, Calculate Reducing Bits?

I ran into a question: in digital system with micro-programmed control circuit, total of 32 distinct pattern operation signal is ...
1
vote
1answer
146 views

“zero voltage drop diode”…Really?

In my research for this question, I found this by a new user that hasn't been seen before or since. His low investment here and the "say goodbye to traditional bad stuff" language makes his answer a ...
0
votes
1answer
77 views

Is it permissible to use fractional aspect ratio W/L for MOSFETs?

I am designing a 2-stage op-amp (Miller compensated). For compensation, I am using a nulling resistance R in series with the compensation capacitance C, with the resistance implemented using a ...
0
votes
4answers
126 views

How to detect reverse-polarity post-mortem?

Original - Apr. 13, 2015 There are many questions here about preventing reverse-polarity, most of them ending up with a series FET that is driven by the opposite supply rail: (shamelessly stolen ...
3
votes
1answer
97 views

Regulator circuit design

I need to design a regulator for my thesis, but I really need help, Please! The topic: - A temperature regulator for a small fridge Some details: - the regulator has to control a peltier element ...
-2
votes
5answers
131 views

Is sequential logic really required to solve some types of problems? [closed]

Can all digital design problems theoretically be solved using only combinational logic, or are there specific examples that have to be solved sequentially? I read that sequential logic is only ...
0
votes
0answers
26 views

Are there any sound design guidelines for high-loudness piezoelectric sirens?

This is a somewhat tricky question so if the title is not clear please correct it. I have disassembled a siren used for auto and home alarm. It was originally driven by a digital circuit with lots of ...
1
vote
2answers
77 views

Designing a MOSFET current mirror circuit

This is the design problem: This is a brief of my design for W and L of the transistors and R: I've connected the upper voltage source to ground and made the lower one equal to 0.4 V to make ...
1
vote
1answer
43 views

How to setup PCB to correct for signal integrity issues after boards are made?

I have a board layed like the in the image below. I have a microcontroller that generated clk1, which feeds into U1. After 8 clock cycles, the clock passes through to U2 and does this 30 times. It's a ...
0
votes
1answer
61 views

Fail Safe for circuit, when input is removed

I have built a circuit which inverts the signal of a ULN2003A, it is in turn connected to a relay. It is possible for the ULN2003A output to be disconnected from the external circuit as it is remote ...