All Questions

Filter by
Sorted by
Tagged with
0
votes
0answers
7 views

IOT - Communication Link

I have an IOT Smart Home project which consists of a central gateway and modules (end nodes), modules and the gateway ...
0
votes
1answer
4 views

VHDL process' sensitivity list

I do not understand the precise role of the sensitivity list in a process in VHDL. For instance, consider an architecture with 3 input signals: a, b, c. I read that if we write: PROCESS (a, b) we ...
1
vote
2answers
33 views

Is MOSFET active device?

The i-v characteristics of MOSFET lies in the first and third quadrant. Therefore it should be passive device acc to me. But I have read that it is an active device. Can somebody tell what is wrong ...
0
votes
0answers
31 views

What is the circuit formation in this electric blackbox?

It should be a simple question from my exercise book, but I could not find the solution for some reason. As illustrated, in an electric blackbox, there is one switch, one 3-volt battery, three 1-Ohm ...
0
votes
0answers
24 views

is there any mico controller with below specs [on hold]

Best Micro controller with 16bit ,QUAD SPI ,inbuilt ADC,3 SPI with minimum 4000 samples with low power consumption
1
vote
1answer
23 views

Why is Rc parallel to RL?

Consider this biasing circuit While determing the AC load line, the author takes Rc to be parallel to Rl. How is it possible since the two resistors have different nodes?
1
vote
0answers
16 views

Slew Rate, Settling Time, Bandwidth, Rise Time - High Speed Transimpedance Amplifier Design

I'm in the process of designing a Transimpedance amplifier for an analytical instrument. The sample waveform (hand-drawn) is attached in the attachments. The requirement is to amplify a pulse kind of ...
0
votes
2answers
10 views

Two Mifare cards: could one be readable and the other not?

I have an RFID keyfob which is used to access my building. The access is not otherwise authenticated (everybody just touches the door with the keyfob and enters) so I was wondering whether I could use ...
0
votes
0answers
14 views

Switching Top and Bottom Layers in Altium?

I was doing a 4-layer PCB, but after submitting for a quote I realized it would be much cheaper to make a 2-layer board and I didn't really need a 4-layer board for the time being. When I was trying ...
0
votes
2answers
26 views

I2C bus communication Issue

I have connected 3 sensors and they are connected to the I2C line of ATMEGA2560 as shown in figure. In normal condition, they are working fine and providing accurate sense value. But, when one of the ...
0
votes
1answer
27 views

Optimum placement, PCB routing for bypass/decoupling capacitors and ground loops

I've seen various answers regarding routing of decaps, wondering which method is optimum for better power distribution and noise immunity: Another question is, will this routing cause ground loops? I ...
-1
votes
1answer
36 views

Can Lead Acid and Lipo batteries be connected together to achieve higher resulting current?

I have a lead acid battery setup which has 3x12V 12Ah batteries connected in series resulting in 36V 12Ah output. I also have 3 LIPO batteries (1x11.1V 3300mAh, 1x11.1V 3000mAh and 1x12.6V 4500mAh). ...
0
votes
1answer
22 views

Can anyone tell me how to find permittivity of a dielectric sample using a rectangular waveguide

Im trying to find the material paramters of a dielectric sample using a waveguide(X band) employing the Transmission/Reflection technique. While performing simulation in CST, how to properly orient ...
0
votes
1answer
30 views

DMG4800 MOSFET running hot (while Si4804 runs cool)

I'm working on a BLDC control system for a micromotor, and have been using the Vishay Si4804 MOSFETs in output stage. Due to availability issues, I ordered Diodes Inc DMG4800LSD-13 for a second board,...
1
vote
0answers
21 views

Change motors priority after power off [on hold]

I have a ventilation system which works with two fan, one of them is active and another one is standby for example for failure case. I want to switch between this two fan after each power of.(when ...
0
votes
2answers
58 views

Generating square wave to be inputted into a MCU

There are signals like below picture inputted to MCU STM32f103: (Offset DC about 800mV, Vmax = 2.4V, f = 66 Hz) I want to change it to a squar wave from 0V to 3.3V being accepted voltage range for my ...
1
vote
3answers
43 views

Arduino oscilloscope voltage divider design

I'm building an oscilloscope with arduino, but I have some questions about how to design the input voltage dividers without ground. The problem is the oscilloscope only needs one input to measure ...
-3
votes
1answer
44 views

What is 0.693, and 1.1, and 1.44 in IC 555 Calculations

I tried a lot to figure out but could not find any answer to this question anywhere. For calculating pulse width in a standard IC 555 astable and monostable configurations we use the following ...
0
votes
5answers
64 views

How are electric water heating elements isolated?

From what I've seen and understood, electric water heating elements are usually copper tubes/pipes with electricity running through them to heat up the surrounding water. I'm not sure if the ...
0
votes
0answers
9 views

Problem setting registers (SPI) [NodeMCU fw, nRF24L01+]

I can read registers somewhat fine, but when I try writing to a register in the nRF24L01+, it either crashes and I have to pull it out of the board, or the register becomes all 0s, and I can't reset ...
0
votes
3answers
59 views

Why is it not possible to create electricity by forcibly putting electrons into the system and closing the loop?

Why is it not possible to make a device operate by forcibly putting electrons into the system, closing the loop, and having electron repulsion do the job of making charge flow? Making electrons flow ...
0
votes
0answers
36 views

why wouldn't a 9-60DCV 20A PWM motor control work to control a 12v 20A wiper motor [duplicate]

I have a question regarding controlling the speed of a wiper motor with a PWM vs wiring in a rheostat in the positive side. I have a 110ACV-12DCV 20A converter going to a 9-60DCV 20A PWM motor ...
1
vote
0answers
41 views

How would 'Electronics Right-to-Repair' legislation affect Electrical Design? [on hold]

Electronics Right-to-Repair has been in the news in the last few years. Some legislation has passed in the automotive industry and it is gaining some traction in agriculture. There's been pushes in ...
1
vote
1answer
46 views

Where will the grid-tie power go if it's not connected to the grid? [duplicate]

What will happen to the extra power that the grid-tie inverter is producing if the demand is less than what the load needs? I have this planned system that I will be implementing soon. The good thing ...
1
vote
1answer
32 views

Current Sensing Design

while using MCP1630 in switch mode power supply design, in the datasheet they gave the input bias current of the "current sense pin" what are the considerations the designer should take while ...
0
votes
4answers
71 views

How do thermal tapes transfer heat despite their low thermal conductivity?

I found myself needing to attach small heatsinks to Mosfets and CC power regulators. Also some high-power diodes. Today I have learnt that thermal compounds, even best in the market, are dozens of ...
0
votes
3answers
55 views

Help choosing a transistor to drive an LED strip from a Raspberry Pi

I'm sure this is a very simple question, but as a (near) complete beginner in electronics I would really appreciate a little help in choosing a transistor to switch a 5v LED strip from a 3V RPi GPIO ...
0
votes
1answer
32 views

Battery life impact with fast charging

Typically fast charging reduces backup time and life. Now a days almost all handsets are coming up with different fast charging capabilities. I'm currently using Galaxy Note9 which has fast charging ...
0
votes
2answers
59 views

Is the direction of an electric field opposite to the direction of a current?

I consider electricity to be an observation of the property of electron mobility. If electrons go the opposite way of the electric field, what is the connection between the electric field and an ...
0
votes
2answers
88 views

Why is information not doubled in this context?

Regarding the following section from a text: Why is information not doubled but increased 4/3 times? Can you give an example to clarify what is meant here? What is meant by information here?
0
votes
2answers
53 views

Bipolar Transistor Inverter Circuit Analysis

I have been trying to understand this question and I'm just not sure what equation to use for the collector current. I'm not sure if I need to be using an output voltage function of time? All I have ...
0
votes
0answers
41 views

Mapping two buttons press as a 3rd button

I got a cheap controller with only 5 buttons. I thought about soldering a few more in parallel so that pressing any of the additional buttons would trigger some other two buttons simultaneously. Then ...
2
votes
2answers
74 views

What is a readhead?

I found this term many times on this website : https://www.renishaw.com/en/rgh34-incremental-encoder-system-with-rgs40-linear-scale--6450 It seems to be something related to a sensor or a transducer, ...
0
votes
2answers
41 views

How does a computer address ddr 4 sdram memory?

I want to be able to manual address a 4gb ddr4 memory stick. looking at the datasheet for ddr 4 there are only address pins from A0 to A17 which is 18 bits, 2^18 = 262, 144 address spaces. So how does ...
0
votes
0answers
37 views

Flyback Isolation Transformer Alternative

I am using the mEZS84801A as a reference design as shown below. It uses the MP8007 PoE chip. I have modified and tested this PoE system successfully and my camera be powered and it can run at 1 ...
-1
votes
1answer
38 views

Battery (e.g, LA, SLA, L-ion) usage recommendation

For the same Capacity requirement, which of the below options is better? 1. Single battery with full capacity (AH) 2. Multiple battery (in parallel) with total same capacity (same AH). For example, ...
0
votes
1answer
24 views

How to calculate the max transfers per frame and the remaining bytes in USB protocol?

Could someone explain the attached table and how the values are calculated? (the table is taken from the official usb 2.0 specification page 42). What I could understand is just the relation between ...
0
votes
0answers
23 views

Sprinkler Controller Wiring (Power) [migrated]

I bought a new Rachio 2 controller and the power has black, white, and ground wires but there are only black and ground coming from my electrical box. My old controller (Irritrol) had the black and ...
-1
votes
1answer
39 views

Looking to make a large surface area 13.56MHz antenna with short range

I wondering about the feasibility of making a 13.56 MHz antenna that would occupy the entire rack of a shelf (5'x2'). The range would need to be small so that it only identifies entities that are ...
5
votes
3answers
255 views

Strange-looking FM transmitter circuit

I found this simple FM transmitter circuit: I built it an it works rather nicely. There are many simple FM transmitter circuits on Google, most of which look basically like this: These work by ...
1
vote
2answers
62 views

P-N Diodes in series. Is my solution correct?

I have attempted to work out a solution on a short question relating to p-n diodes. Is my solution correct? The question (from a past paper) : From the question I understand that there are two ...
-1
votes
1answer
30 views

Connecting LiFePO4 battery to existing UPS (uninterrupted power supply)

I want to install LiFePO4 batteries with the UPS in the link. Can you please guide me how to do it? The UPS has built in charger and that's what i am confused about. http://www.aptinverex.com/...
-2
votes
1answer
74 views

What type of connector is this for a 24V battery and charger and where can I get them?

I need to identify this connector so I could order it. I also need to find a place where I can buy them.
1
vote
2answers
57 views

Will a 2.4GHz WiFI/Bluetooth antenna create noise in my sensitive EEG measurement circuit?

I'm designing a circuit for doing EEG measurements and I want it to be very compact. As a result, the WiFI+Bluetooth antenna (2.4GHz) will be sitting half an inch above the electrode inputs. Will this ...
0
votes
2answers
50 views

Increasing output current of DAC

I have an application where my Arduino is controlling a mcp4725 DAC for a design replacing a sensor on an old car. The DAC provides the analog output voltage, .25V to 4.9V to the computer. I recently ...
0
votes
1answer
50 views

Resonant Circuits do all capacitors count towards resonant frequency?

I am trying to design a variable frequency oscillator for use in a superheterodyne FM receiver and have been reading First Steps in Radio (http://www.arrl.org/first-steps-in-radio). In this example a ...
1
vote
1answer
120 views

Why are laptop computers usually powered around 20V DC?

Most electronic devices use 3.3V, 5V (all USB devices), 9V or 12V (very often for electronic music gear), and we usually all have dozains of such wall adapters at home. Even desktop computers have ...
0
votes
1answer
26 views

dimmer on input of stepdown transformer for amp regulation?

If have a step-down transformer designed for low voltage high amps, and I put a dimmer on the input will that allow me to lower the output amps? I don't care about voltage as it will be negligible, I'...
0
votes
1answer
67 views

First metal detector by Alexander Graham Bell, how did it work?

Alexander Graham Bell developed a similar device (metal detector) to attempt to locate a bullet lodged in the chest of American President James Garfield in 1881; the metal detector worked ...
-4
votes
0answers
48 views

Constant current source with capacitor [on hold]

What will be the plot of Vout wrt time? This is the solution I came up with.For t>0,I cannot understand which capacitor voltage to consider.

15 30 50 per page