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

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2answers
47 views

concept for true random number generators

I have an idea. Lets say we have an unpowered TTL set-reset flip flop with both inputs tied to 5v(logic high). When we apply power to the flip flop, it goes into a quiescent state, so there is no ...
2
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0answers
46 views

Antenna Design for specific directions

I am designing an antenna for a device and was hoping to gain some insight in the correct design direction for the antenna. The Idea: A receiver & antenna that fits in a 6" diameter by 3" deep ...
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3answers
76 views

How to determine how much current and or voltage a given circuit “needs”?

My apologies in advance if I make any wrong assumptions. Say you have an outlet that is rated at 120V and 10A. My power adapter for my MacBook says it is rated at 16.5V and 3.65A max. How was it ...
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1answer
33 views

Using a digital signal to turn on and off a vibrating motor

I'm designing a circuit with the IOIO-OTG board and a vibrating motor. The idea would be to have a digital pin on the IOIO board control the state of the motor (either ON or OFF). The motor operates ...
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2answers
43 views

Building a first State Machine circuit - Technical Help

I just learned how to synthesize a diagram of a finite state machine into a diagram of a logical circuit composed of D flip flops, a clock and logical gates. However, I don't really have much ...
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0answers
26 views

Trouble getting push button working in Nios II

To give you an idea of what I'm trying to accomplish, the 18 LEDs on the board are to scroll right to left, then back to the right, and keep looping as such. Where the push button comes into play is ...
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0answers
63 views

What can I do with Cadence OrCAD software?

As the question says, what can I do with the Cadence OrCAD software rather than PCB design and schematics? I didn't understand what the Cadence website is saying. I just downloaded Cadence OrCAD 16.6 ...
2
votes
1answer
45 views

CadSoft Eagle polygon won't reach pads in Molex library

I'm using the Molex 5569 library in CadSoft Eagle. When I create a polygon, it won't reach the pads at all. The problem occurs only with components from this library. Have a look at this screenshot ...
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1answer
46 views

How can I trigger other circuits based on specific values of a 12 bit ripple counter?

I've built quite a few circuits but I've never really designed anything from a "schematics first" approach. Mostly just tinkered with designed and code until I got it right. Now, I want to build a ...
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1answer
88 views

Choosing the right capacitor

I have been told that in order to not damage a battery is better to connect it to a capacitor, to deliver current in a smooth way. This is because we are using a circuit where a peak of current is ...
2
votes
1answer
76 views

MOSFET H-bridge design

given the circuit below to be used as a H-bridge with AVR PWM. Is this a good desing to use? What can you recommend? I already built something like this but without the resistors. ( and so burned ...
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1answer
54 views

BJT Topologies - Design Principles at RF

Here are some rules of thumb I've learned when designing single-transistor BJT amplifiers: High input impedance is good Low output impedance is good Biasing resistors should draw ~10% of the ...
3
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3answers
185 views

custom FPGA PCB Design tips

I am planning to design a custom FPGA PCB. the PCB will contain sensors. I need to read the output of the sensors and process them in the processor. I have completed many projects using FPGA's, but ...
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1answer
64 views

Add male pin headers in DesignSpark PCB [closed]

I've been struggling with this software to find male pin header connectors but I could not find it even on the online database, has anyone an idea ? Thanks!
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4answers
1k views

Will my circuit work?

I have a circuit that I believe will work, but I was hoping someone could double check? Removed image to make room for edit. - Original schematic In my circuit, I use a MOSFET, a photo-interrupter, ...
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3answers
144 views

Are 3-8 input NAND gates common?

If I have, for example, 4-8 (or more) inputs that I need to AND together (or even NAND or OR) should I look for larger input devices like the 7430 NAND or is common practice to daisy chain multiple ...
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2answers
85 views

Simplest possible oscillator (with some constraints) [closed]

I'm interested in finding an oscillator circuit that meets the following constraints: Runs on 9 volts or less Periodicity 100-1000 Hz or so Non-sinusoidal oscillation No inductors 1 transistor or ...
1
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1answer
35 views

Analyzing/designing positive feedback amplifier

I've been searching all around to find a tutorial on analyzing/designing a positive feedback amplifier, especially a single transistor in common collector mode, but with no luck... So, lets say I ...
2
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3answers
458 views

Logic design to circuit — how is it generally done?

So I've designed this CPU with purely logical components (basic logic gates), now how would I go about converting it into a circuit? I know that logical gates can be implemented using transistors, but ...
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2answers
155 views

Resistor required for capacitor?

I'm currently working on some simple circuits to learn about circuitry, and being a Physics major I have a pretty good grasp of the mathematics and concepts, but I'm a little confused about ...
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1answer
87 views

Topology for a DC-DC step up converter for a single AA battery with 50V 10mA output

I need to design a very compact step up DC-DC converter for the single AA battery (input voltage 0.7-1-5V) with an output of 50V 10mA. The load should drain in a typical case about 2mA, but in certain ...
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votes
2answers
84 views

How many people might have been involved in the design of the Macintosh SE? [closed]

It is really difficult for me to know how many people were in charge of the development of this electronic wonder. When I'm struggling to properly comprehend transistors and how they work, these ...
1
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2answers
224 views

High EMI PCB track under transistor or diode package

Can a high EMI PCB track under a transistor or diode package (in this case TO247AC) be a problem? To get a better understanding: Is there any advantage on putting these tracks on the other side ...
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1answer
101 views

Low-cost Up-Down Servo solution

I have a small project and I'm interested "upgrading" to a more produce-efficient design. Please note I'm no electrical engineer. I want to move a small servo (like this one ...
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3answers
111 views

Should I use CMOS vs. TTL?

Now, I know that this question has been asked so many times that it seems like I'm trolling, but I must point out that I couldn't find the right answer to this question anywhere. So yeah, CMOS and ...
0
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1answer
52 views

fpga verilog dual access

I need to write to a register from 2 sources.. in this case, a pci host and a microcontroller. The 2 will never access the register at the same time (basically once the PCI is done , it hands it ...
2
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2answers
96 views

How to design a LIFT simulator using FSM(Finite State Machine)

I want to design a LIFT with the help of Finite state machine. There are four floors. So I took them as 0, 1,2,3 and correspondingly the states. The 0,1,2,3 buttons are present inside the lift. If ...
2
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2answers
147 views

Designing shortwave radio receiver

I was building a receiver circuit ( superhet) for shortwave radio, primarily for 20m ( 14mhz) band. The circuit uses 3N211 or 40673 mosfet for mixer. However I have only these components available at ...
2
votes
2answers
72 views

Dynamic Logic - Transistor Sizing

If we have a circuit in dynamic logic: What should the size of the charge transistors (Qe and Qp) be? I know that increasing the size improves the speed but also increases the dissipation, and that ...
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2answers
83 views

Designing with ARM SoCs [closed]

I want to learn how to design and develop boards for SoC systems (i.e. i.MX from Freescale). This can be real useful to me because there are countless things I could do with the possibility to design ...
2
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1answer
256 views

Reducing Undershoot and Overshoot in a custom voltage regulator?

I'm trying to build a voltage regulator that takes in a reference voltage and an unregulated voltage (to power the components, and this voltage is always greater than the reference voltage) and ...
1
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2answers
338 views

Current limiting voltage regulator to power 12VDC fans

I'm building a ventilation system that will blow air into the back of our parked SUV. Creating a plastic fan enclosure and installing the fans is no problem, but the electronics... well, that's a ...
0
votes
1answer
58 views

Power analysis after placement and routing of ASIC

How can I procure the files stating the details of power consumption of the chip after PNR in SOC Cadence Encounter?
3
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2answers
87 views

How does this shunt regulator work?

I'm investigating battery monitors and I'm looking at TI's BQ76930 to take care of an 8 cell 24V LiIon. They provide the datasheet for their evaluation module (PDF warning) which includes the board ...
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0answers
93 views

Designing an efficient PSU

I am designing a PSU capable of producing 5 watts @ 5V 1A. The design will power about 12 RGB LEDs (totaling about 400mA @ 5V) and a audio class D 1.4 W amp. Space is no issue but efficiency and cost ...
4
votes
4answers
753 views

Why peltier elements have smaller heatsink on cold side?

I have seen in nearly all configurations that Peltier elements are mounted with huge heat sinks on hot side as compared to tiny ones on small side. Is this just a way of explaining the need of heat ...
2
votes
5answers
184 views

Heat sink, how much does fin and base width matter?

I have lot of aluminum sheet 0.5mm thickness at home, normally heat sinks that I have seen had 1mm thickness. Now I am wondering should I get that sheet welded as heatsink or do I absolutely have to ...
4
votes
2answers
201 views

Would a better heat sink be tall or wide?

If we have a heatsink and want to improve it's efficiency would it be better to increase its width or height? What should be the strategy on installing a fan as well? If we increase height and ...
0
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1answer
56 views

Should same sized peltier elements be cascaded?

I learned that peltier elements give better cooling on cascading but need to be growing in size towards the hot side. I have 4 peltier elements of 40×40×35mm and I am planning to make a portable ...
2
votes
2answers
165 views

Designing a low voltage UPS

Preface: I am designing a UPS such that if the AC main fail the device can continue to run for at least 10 days. My goal here is to make a design that can last years off a non-rechargeable battery. ...
11
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4answers
2k views

Make a custom plastic case

I have worked on many electronic DIY projects like MIDIbox (http://www.ucapps.de/), it always was fun and working but at the end, the problem was that I ended with a cool gear, but in a poor casing, ...
2
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2answers
98 views

How to completely turn off device when float switch is open

Background Below is the circuit I designed to open a solenoid valve after a delay from C2 (represented by L1). S1 is a float switch which closes when a resevoir goes below a given level. The reason ...
1
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2answers
99 views

300W Boost converter design

I am designing a boost converter. I know maybe the specs I want would suit better in another topology like Half-Bridge or Full-Bridge but the boost topology is simpler and inductor winding is simpler ...
1
vote
2answers
144 views

Designing a voltage follower that can provide up to 5A of current to a load

I'm trying to dabble in analog circuit design, but I honestly am a complete newcomer in this area as my strengths are in CS. Sorry if this question sounds stupid, but can anyone help me with designing ...
3
votes
3answers
228 views

Electrical issue with USB ? Hi-speed device not working on own design

Disclaimer, I'm a SW guy, so please don't take anything for granted, and I would appreciate explanations in layman's terms :) We have a custom design based on ...
3
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4answers
506 views

Design vs reality and what to do when they differ

I've been trying to focus a bit more on Analog circuits lately and found that my design and actual results often don't match up exactly. An example is a Pierce oscillator I built a while back, the ...
2
votes
2answers
152 views

CPLD: my first project

First, I posted similar question on CPLD/FPGA users forum, however, they do not seem to be as active as StackExchange. So, I hope it will help me to get going with CPLDs and also will be useful ...
19
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7answers
2k views

One large microcontroller, or lots of small microcontrollers?

I'm used to doing basic and straightforward things with microcontrollers, relatively speaking. Things such as driving LEDs, running motors, basic routines, GUIs on character LCDs, and so on, but ...
0
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2answers
147 views

Value of inductor

I need to wind an inductor with a value between 47uH - 200uH. I have a 10 mm (in diameter) ferrite core from an RF choke used in an old radio (probably lossy ferrite). The core is 3 cm long (I also ...
1
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2answers
126 views

Designing effective usage time from 12v car battery

Need a little power design help: I have a project I'm working on where I have measured that I will use approximately 14.4Ah over 24 hours. This is quite the load for a small timelapse setup where I ...