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

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Can I connect many SX1272 (LoRa) based devices to a gateway?

Simple question: Is SX1272 chip by Semtech capable of sending data to LoRa gateways? I'm a little bit confused about LoRa and LoRaWAN. What is the difference?
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2answers
16 views

what are advantages of northbridge chipset

What are advantages of having a northbridge chipset in a computer motherboard? And if it has such advantage, why new processor integrate some of its features into CPU?
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1answer
44 views

How to make an Audio Amplifier

I am about to attempt make my first audio amplifier (beyond an LM386 amp). I chose the TDA2030A (dataheet http://www.st.com/web/en/resource/technical/document/datasheet/CD00000128.pdf). Since its a ...
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1answer
43 views

How can I assemble and control two different hands on a watch face?

I want to make a device with two hands that rotate independently of each other, just like the hour and minute hands on a watch. I'm struggling to figure out how to actually design and implement this ...
4
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1answer
126 views

Why is this diode here?

I am building a VU meter. Searching in the Internet and coming up with some things on my own, I ended up with the following circuit First, there is an amplifier whose role is to give the VU meter ...
3
votes
3answers
91 views

Design help! — Play a pure tone into a mic and depending on its frequency a specific LED will light up

I'm still new to electronics and am making this in order to learn more about circuit design and filters. I do not want to use microcontrollers. I want a purely analog solution. I'm trying to make a ...
3
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1answer
79 views

What is a good way of estimating how long a battery will last for powering up a microcontroller

I know this is going to be a broad question, but I'm looking for a broad answer that can get me a ballpark figure. When building a board with microcontroller, what's a good way to estimate how long a ...
2
votes
1answer
249 views

Why would someone prefer halfwave rectifier over bridge rectifier? [duplicate]

The other day, out of curiosity I was measuring the current wave shape of a laptop charger. The wave shape indicated a spike only in one half cycle. I'm guessing half wave rectifier here. One thing ...
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1answer
26 views

how to remove this error “ERROR 152: Port on instance does not exist in entity declaration for instance”?

I am new to Cadence Allegro HDL for schematic design and for my first design i got this error. In 728 page document provided by cadence its is mention as follows, "Open the symbol for the component in ...
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1answer
74 views

How to design a circuit with array of amplifiers? [closed]

If I have a very tiny signal voltage and I want to amplify it 100 times higher with low noise amplifier, how should I design the circuit? I mean for example how should I know that I need capacitors ...
0
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1answer
74 views

Power supply logic design [closed]

I have three power sources that supply voltages from 3 to 9 volts. This will be going into a positive voltage regulator for stable output. If the third source is present it takes precedence over the ...
4
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3answers
120 views

Why is USB type C connector hollow?

If we look, for instance, at a Lightning cable, its connector is shaped like "—", with receptacle being "=". Apparently, this construction contributes to durability, to the ease of use, and lowers ...
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2answers
112 views

Designing USB device [closed]

I want to build a USB peripheral device. The Device is to connect to an Android smartphone with USB OTG capabilities. The smartphone will be a host and will run an app that communicates with my ...
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1answer
65 views

Guide to effecient/neat circuit design (etch and proto PCB)? [closed]

I'm starting to delve into slightly more complex prototyped PCBs and (eventually) will be etching boards. All the guides I've read have been quite basic about the process, but I would like to know if ...
2
votes
1answer
41 views

Parallel bus trace width and spacing

I have been working on designing a PCB for a Z80 computer that I plan to sell a few times for interested people. The Z80 will work at a maximum of 8 MHz and has parallel lines going to a system ...
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0answers
55 views

Where to find maximum current for FPGAs? [duplicate]

I am designing a project using te EP4CE6 FPGA. The problem is i cannot find the maximum current it can draw from each rail anywhere. There is the excel tool for calculating consumption that I cannot ...
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2answers
52 views

How can I determine what type of resistor, transistor and, diode I need?

I'm trying to build the following circuit Given my solenoid draws 1.4A, how do I determine what type of resistor, transistor, and diode I should use? What if I were to change my power to 9V? I'd ...
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2answers
36 views

SPICE Programs worth learning for [closed]

I was wondering what are the professional SPICE programs for simulating analog circuits in the industry now. For example, where the big companies like Atmel simulate their microcontrollers, or a ...
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0answers
33 views

wheatstone bridge pressure sensor configuration

I'm a student working on a pressure sensor that requires voltage amplification in order to read a 0 to 5V output on an ADC input for a PSoC CY8CKIT-042-BLE pioneer kit. Voltage supply is 5V DC In ...
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1answer
60 views

SX1272 - LoRa - What is the minimal schematic (needed capacitors/resistors) to use that device?

I'm interested in SX1272 by Semtech. It's a LoRa modem. I'm not the best at reading datasheets. Maybe it's because of my poor English. I wonder what is the minimum schematic of such a chip? What ...
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1answer
113 views

Building a low-cost oscilloscope and a function generator [closed]

I want to build an oscilloscope and a function generator as a graduation project in my university. Cost should not exceed 125$ or 250$ if the project has more additional features. I will display ...
0
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2answers
55 views

where i can find allwinner library for eagle

I work in a project using Allwinner a10 CPU and eagle software i did't find the library I already tried to searched in google and github many time for Allwinner a10 library for eagle software but I ...
6
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2answers
113 views

MOSFET Circuit Design and Thermal Considerations

I'm a newbie at EE, and just I wanted to verify that the design I came up with for a MOSFET circuit that drives a 12V 500mA water pump will work. I'd also like to confirm I can run the N-Channel ...
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0answers
26 views

Colpitts dimensioning for high leakage sensitivity

I've got the following problem: having a coil with inductance L=22uH with equivalent series resistance R, how would you design this Colpitts oscillator in order to make its oscillation amplitude ...
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1answer
114 views

Is this memory card circuit designed properly

I'm looking to build a reusable memory card for my SRAM as the cost of the chips can get up there. I'd like to be able to plug this into other projects (mainly with a W65C816S as I work with it) both ...
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1answer
61 views

How to pick capacitor dimensions

What are the tradeoffs and design considerations for capacitor dimensions? Specifically, I need to select 2 electrolytic capacitors (C2 and C3) for a car voltage (noisy 12V) to 5V converter. Here's ...
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1answer
50 views

Are those calculations for primary coil of a transformer correct?

The calculations in this question are based on my previous quesion: How many turns do I need for the primary coil of a transformer? Marko Buršič said : "B_max shall be between 1.3T and 1.6T, but not ...
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2answers
59 views

Series RL Circuits in AC

Could anyone help me with this question I just want to know how the schematic looks like ?
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2answers
233 views

I2C not working on my first PCB design

I built a simple sensor board connecting a RFDUINO to two I2C components. A ADXL345 accelerometer and a MPR121 Touch controller. The board also includes an RGB LED, vibration motor and Li-Po ...
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3answers
87 views

Should HDL languages be taught before software languages? [closed]

I'm a Computer Engineering student and learned the basic sequential programming languages (C/assembly/Java) way before I was even introduced to HDLs. Thus, my whole programming logic was based upon ...
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1answer
38 views

How to drive an LED for status using Card Detect pin?

There is a Card Detect pin on most SD Card connectors, it gets pulled to ground when SD card is inserted. My question, is there a way to drive an LED as a status indicator using this GND signal. I am ...
1
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1answer
51 views

Necessary things in LPC1343 basic development board

I have finished my LPC1343 basic development board,just based on specs from datasheet and some referred from microbuilders.eu. I'm unsure if the board design is good or not so I've attached my ...
1
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0answers
51 views

Layout recommendations for an older DC/DC

I'm currently working on getting an old voltage regulator chip from TI to work. The TPS65530 is an 8-channel DC/DC Converter and thus quite crowded. I have not been able to find a reference design ...
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0answers
27 views

Chebyshev filter design.

hello, I am really stuck with this question, I was wondering if anyone could help me with it? like I am not sure which way is best to approach it
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3answers
49 views

Analog filter resistors and capacitor tradeoffs

I am designing a filter to obtain a dc reference from a signal, and I am thinking about using the schematic below for a cutting frequency of 1 Hz: simulate this circuit – Schematic ...
6
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5answers
510 views

Tradeoffs when choosing the op-amp package: quad vs dual vs single

Let's say as an example that I need to use four op-amps in my project. I don't have any super strict requirement of space and price. Which are the parameters to take into account when choosing the ...
1
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1answer
116 views

Modern jack-of-all-trades cheap OPAMPs? [closed]

I am trying to design my first "big" project, and I have to choose the OPAMPs to use. The problem is that I am feeling overwhelmed by all the possibilities. I feel tempted to just stick on the LM741 ...
0
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1answer
22 views

multi channel buffer

What is necessary to drive two op amps (tl071 for instance) from one piezo guitar pickup, which of course is a very high impedance source? Result being, one very high impedance source creating two ...
2
votes
1answer
157 views

Is there any science (or trick) to determining a replacement op amp?

I have a "mature" circuit design that calls for an LF411 op amp. I've built it up with a through-hole PDIP and it works just fine. Now I'm designing an SMD PCB for the circuit so I have the ...
0
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2answers
53 views

Connecting Analog GND and Digital GND of ADC

I'm trying to make a simple line tracing robot, however I couldn't figure out how to connect AGND and DGND of A/D converter(MCP3208) on a simple perfboard design. I need some guidance how to smooth ...
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1answer
47 views

Connecting Sensors To A Production PCB

Background: I designed a simple board a while ago using a ATMEGA328 and a ESP8266. The idea is that the ATMEGA deals with sensor data and the ESP8266 deal with the whole online bit. I did a initial ...
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1answer
62 views

Why is ground shared between primary and secondary side in LT3750 circuit example

LT3750 is a capacitor charger controller IC. The sample (typical application) circuit in its datasheet shows an otherwise isolated secondary side sharing a ground with the primary side. A PCB layout ...
0
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1answer
45 views

Finding Optimal Resistor Combination for Desired Equivalent Resistance

My question is simple, though I'm not sure how to succinctly word it in the title. Often times when working with circuits (as a student) we need a specific resistor value, but only have resistors of ...
-3
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1answer
112 views

School Project : To determine Eq. resistance of a cube whose each edge has a resistor, say R [closed]

Background I am a high school student, we are supposed to submit a Physics Project, individually. Since I have never done any Electrical Project/Experiment before, I came up with the idea of making a ...
2
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2answers
60 views

“window utilization”

I would like an explanation of the importance of window utilization in transformer design. I understand that it is the ratio of area occupied by windings to total area available for windings on the ...
0
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2answers
75 views

Inverter Design - What DC input voltage for most efficient DC to 120VAC inverter

I have seen several online circuit diagrams for a DC to AC inverter. Commonly many inverters use a transformer to step up 12V to 120V. I understand that inverting from DC to AC requires additional ...
0
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1answer
35 views

Comparator power dissipation

I want to calculate the LM339 comparator power efficiency, so I thought the best way is to calculate the output RMS power and the Power dissipation and the quiescent(DC) power then will get the input ...
3
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3answers
155 views

Narrow active band pass filter design

I'm trying to design a filter that allows through a 1kHz sine wave, based on my university lecture notes I have the following transfer function for a multiple feedback band pass filter: $$A(s) = ...
0
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1answer
33 views

Power normalisation of a signal

I have two signals, say a and b. Signal a has power of 6 Watt. Signal b is summation of signal a and noise n and has power of 7 Watt. I want to normalize the signal b in a way that its power is equal ...
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1answer
40 views

Maximize power to RL with LM741 output

I have to design a circuit that maximizes power to RL which is a resistance representing a speaker attached to the end of a LM741 op-amp. This is a non-inverting op amp in the circuit, and I just need ...