0
votes
3answers
27 views

Why would a time signal receiving watch have an airplane mode?

I've been looking at radio controlled watches online. I noticed that some radio controlled Casio watches have an 'airplane mode', which disables GPS and terrestrial time signal reception: Now, why ...
0
votes
0answers
9 views

Li-ion battery charging and usage

I have a project in mind based around a Raspberry Pi Zero. The case I am using has slots for two AA batteries so I thought I would use some of the AA sized Li-ion batteries. The batteries I want to ...
0
votes
1answer
20 views

How is a latch different from Schmitt Trigger?

Consider a simple latch (two cross coupled inverters). The positive feedback makes the circuit operate in either of the two stable states if the overall gain is greater than unity. If there is a ...
0
votes
0answers
16 views

How sound waves travel for reverse parking sensors?

Looking at (ultrasonic) reverse parking sensors, they're all installed with a (plastic?) cover like this: Traditional ultrasonic sensors are installed with a mesh: Since plastic reflects sound ...
1
vote
0answers
17 views

What determines the actual power consumption of writing to a microSD card?

I'm currently working a project that will feature writing data to a microSD card. Because my project will be battery powered with a 125mA power regulator, I'm concerned that my write operations will ...
1
vote
0answers
49 views

How important is the direction of a transistor

I am trying to assemble a class D amplifier from a kit. The instructions for the kit do not specify how I should orient certain transistors. The PCB has the outline of white semicircles underneath ...
0
votes
2answers
25 views

AC to DC wall adapter circuit

I'm trying to design an ac to dc conveter (230V ac to 12V dc). Haven't decided on the current yet. It's likely to be around 2A. I want the circuit to be compact and hence I think it is best to follow ...
0
votes
1answer
22 views

SIM900 antenna design

I'm designing a hardware for a hobby purpose involving SIM900. I'm a newbie when it comes to antenna design. I was wondering what would be the best antenna choice to start with. Even though chip ...
0
votes
1answer
24 views

PIC Microcontroller - __delay_ms() no effect

I am newbie to C programming on a pic microcontroller. I am slowly working my way through the various tutorials and literature available to try and apply my knowledge. I am currently trying to blink ...
1
vote
2answers
27 views

Analysis of overdamped series RLC circuit (from “Foundations of Analog and Digital Circuits”)

I'm working my way through "Foundations of Analog and Digital Circuits (Agarwal)" and am, for the first time, stumped. Specifically, they analyze an over-damped, undriven series RLC circuit in ...
1
vote
1answer
23 views

What's the difference between all of the Atmega328p clocking options?

Reading through the data sheet of Atmel's Atmega328p microcontroller, I had heard reference of an internal 127kHz RC oscillator. This being the default oscillator if no external crystal/resonator was ...
0
votes
1answer
26 views

I²C interface between 3V/5V sensor and a 2.4V MCU

simulate this circuit – Schematic created using CircuitLab I have an ultra low power application where the minimum VDD of my temperature sensor (ADT7420) is 2.7V, while I need to run my MCU at ...
-2
votes
1answer
25 views

Why start and run capacitor is used and explain it operation?

What for start and run capacitor used in induction motor why it is not replaced for compensated winding in the motor and why run capacitor is different from start capacitor
-2
votes
0answers
38 views

Charged capacitors in series [on hold]

Two ideal capacitors, C1(=2F) initially charged to a voltage of 5 volts and C2(=3F) initially charged to a voltage of 10 volts, are each connected in parallel with a resistor 5 ohms. What is the ...
1
vote
3answers
83 views

No output voltage on wiper when using pot as voltage divider

I've been trying to teach myself about potentiometers and how they can be used as voltage dividers. I'm still very new to electronics. I bought some Alpha 10k linear pots to use in a really basic test ...
0
votes
0answers
15 views

What is the power consumption of each rails of Broadwell-DE(D1548) in stand-by mode? Is there any document for this?

I am new with Broadwell-DE based designs. Questions: What are the power consumption of each rails of Broadwell-DE(D1548) in stand-by mode? Is there any document for this? I have checked the ...
1
vote
1answer
39 views

Will this AC-AC SSR work for a safety start / stop switch for a power tool

I'm modernising an old bench saw, and I want to replace the switch it has with a safer one, so that the tool will not start if the power is disconnected and then reconnected. The usual way to do this ...
0
votes
1answer
17 views

IR2110 Mosfet Driver - Separate VSS and COM (power-logic ground)

I want to design a low budged class D amplifier based on the IRAUDAMP1 and I have a quick question. Will there be a problem if my Logic ground and Power ground pins from IR2110 are sparate (never ...
0
votes
1answer
41 views

AC Voltage to Spark Plug

To get a spark plug to fire I read that it requires approximately 12,000 Volts. If I have an ac generator giving a RMS Voltage of about 10 Volts (pretty small) what do I need to do to get the spark ...
1
vote
1answer
21 views

help on making a bluetooth proximity device [on hold]

i want to make a small bluetooth proximity sensor. simply a small button like device that only serves as a bluetooth connection to my phone, and when my phone gets out of range of said device it will ...
0
votes
2answers
40 views

Is this address decoding circuit correct?

The problem is to design an address decoding circuit for two 4Kx8 RAM chips at the 2050H . We have 16 address lines. So, for 4Kx8 RAM we need 12 address lines to address the memory. Remaining can be ...
0
votes
2answers
22 views

Dual shaft servo motors? Do they have another name?

I am trying to find a servo motor where the shaft protrudes through the other side however I haven't been able to find much online. I am wondering if I have the term right though. Am i right searching ...
0
votes
2answers
30 views

accurately move an object in linear steps with electro motor

How would you tackle the problem of moving an 1-2 kg object in a linear fashion from point A to B to C and than back to point A and so on? Points A,B,C are fixed and require high accuracy. This image ...
2
votes
1answer
68 views

Removing QFN vias

I've used the footprint wizard to generate QFN package, the result: My question is, if it's OK to remove the vias since I want to put some components to save same room?
2
votes
1answer
129 views

Go around short circuit protection

I recently bought a lithium-ion battery that has a built in protection for short circuit. I want to power a thermoelectric cooler with it. But when i connect it to the battery it seems that the ...
1
vote
2answers
48 views

Calculation Inductance Voltage in book 'Practical Electronics for Inventors'

I'm curious is calculation in screen right? I assume Voltage from 2-3 sec must be -0.2V, because dI/dt=(-1)-1=-2A, not -1A. Am I right?
1
vote
2answers
27 views

Total power from 2 different solar panels

I was thinking about solar panels for a while and a question popped into my head which i still can't answer nor test it, and i want to know if this would actually work: If I get a 2x12v solar panels ...
-3
votes
0answers
34 views

component label wm [on hold]

I have a missing component on a PCB that I need to add, I do not know what it is but causes the board to function the same as the ones with it present. It is labeled WM103C on the board. Can't see ...
1
vote
4answers
69 views

Why aren't there any 3-phase domestic power-outlets, or any interest in 3-phase for household (mains) power or anything relatively low-power?

Since I discovered what 3-phase electrical power is on Wikipedia, I have noticed that it's associated with very high-power applications. I have not been able to find anything on the subject of 3-...
0
votes
2answers
29 views

Measuring switched mode power supply efficiency accurately for high currents

I hade implemented a switched mode power supply: * 1.2 kW * Input: 12 VDC, 100 A * Output 5 VDC, 240 A I need to measure it's efficiency (power loss/total power) by accuracy of 1%. In other words: I ...
0
votes
1answer
34 views

how to store data in arduino

is there are an Arduino module that can store excel data which can be use for comparison the present data by sensor.i want to built a prototype that can use combination between 2 sensor which can ...
1
vote
0answers
25 views

No output for C++ GPIO code for beaglebone black

could anyone tell what could possibly be wrong in the following C++ code for enabling and setting pin no 49 (p9_23). I am directly checking the output on multimeter. ...
-1
votes
0answers
4 views

MATLAB,Signal Processing [migrated]

Is it possible to convert a PDF to .mat file for processing in MATLAB? I have ECG signal in PDF format.I want to process it in MATLAB
-1
votes
2answers
37 views

How holes and electrons in the diode gets back to their original position when it is turned off?

When diode is turned on the holes and electrons gets mixed that is the holes will also appear largely on the n side and electrons also appears on the p side but when turned off how electrons and holes ...
0
votes
1answer
38 views

Laser power necessary to cut/etch paper

I want to cut/etch (would be satisfied with just etching, though prefer both) paper with a laser. I have on hand several laser diodes salvaged from various disk drives and a 633 nm 10 mW CO2 laser. I ...
0
votes
2answers
29 views

Conservation of flux linkage

What is conservation of flux linkage ?? Please explain with suitable diagram. I understand charge conservation and textbooks usually say that flux linkage conservation is analogous to that, but they ...
2
votes
2answers
157 views

How to read 1/4 audio jack data sheet?

I am trying to layout my own pcb for a guitar amp similar to but I am confused how the IN symbol that corresponds to the audio jack is supposed to be connected. Switchcraft Inc. RN112BPC I am ...
0
votes
2answers
37 views

Does propagation delay in an opto isolator sum with switching time in a FET?

Optoisolators such as the Vishay VO3120 list a "propagation time delay time" of 0.4 microseconds. Common FETs such as the IRFZ44N list a "Turn-On Delay Time" of 12 nanoseconds. Normally I use the ...
2
votes
3answers
171 views

How does a transistor behave when the gate is disconnected?

On an n-type transistor, if a voltage above a certain threshold is applied to the gate, current can flow from source to drain. On a p-type transistor, if a voltage below a certain threshold is ...
0
votes
2answers
63 views

What Makes a Radio Transmitter Powerful?

I've been doing research on radio transmitters, and though I understand how the signal is generated and how data is transmitted, I still can't understand what defines a radio's transmitting power. How ...
0
votes
0answers
37 views

Chinese CH340 Arduino Uno - Burning stand allone chip [migrated]

I followed regular tutorial and I was able to burn boot-loader on my standalone ATM328 chip, but because I'm using this CH340 UNO and example is with regular UNO, I can't just remove the chip from ...
0
votes
1answer
35 views

Solar panel powered regulated output voltage collapses after short run-time

I have a PWM DC motor controller for a water pump. Input voltage 24 V large solar panel (the ones you get on houses). The PWM has a L7812 so outputs 12 V max. Pump 12 V, 0.9 A. Everything starts ...
0
votes
4answers
39 views

HF transformer fed fed diode rectifier not working

As part of my pure sine wave inverter, I have a DC - DC subsystem in which a signal stepped up through a HF transformer is put through an uncontrolled diode rectifier to get a DC output which I am o ...
-1
votes
2answers
37 views

USB3 activity detection

Some USB hubs have status LED that shows activity. Let's say, I want to make a USB3 cable with status LED that would indicate any activity on the bus (changes of differential voltage). Is there a way ...
1
vote
0answers
38 views

Current across high speed mechanical switch contact even if it can’t be measured?

If I am cycling a mechanical switch at a frequency higher than the bandwidth of a current amplifier and biased using a DC source, is current actually flowing across the contact? The following ...
1
vote
2answers
61 views

Battery powered Arduino on a breadboard

I am trying to run a low-power, battery powered Arduino on a breadboard. I followed these instructions exactly: https://www.openhomeautomation.net/arduino-battery/ I uploaded the "Blink" sketch to ...
3
votes
1answer
153 views

2 ideal inductors in parallel

Would 2 ideal inductors in parallel carry currents according to current division even if the excitation is DC? I am asking this because my spice simulation is showing they will carry equal currents, ...
0
votes
0answers
37 views

Time delayed circuit for car

I'm trying to make some kind of time delay circuit. After I turn off the relay, that lamp is lighted for another few seconds. My idea is shown in schematic below. I have 2 questions: What value i ...
0
votes
1answer
39 views

Shrinking drill hole size in Eagle

The last time I did a successful PCB, the drill hole size relative to the component pad size is rather huge to the point where when I entered the soldering stage, the component wires were not ...
0
votes
1answer
29 views

MCP2221 USB To UART Programmer

I am very new to the electrical design and had a very basic question. I am trying to program a Atmega328p using the MCP2221 interfacing chip. I picked this chip due to it being the only converter I ...

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