All Questions

0
votes
2answers
29 views

Unit Gain Op amps not working LM2904p

I am trying to use the LM2904P as a voltage buffer. i am using a volt meter at the output, and i get 10v when it should be 2v. This is pretty much what my setup is. - is In1- and + is In1+. i dont ...
4
votes
1answer
33 views

Best way to crimping the outer tabs of a Crimp Terminal Contact

I'm trying to find the best way to crimp the JST VH series crimp terminal contact I'm using my Knippex tool to perform the crimp Now I always get good results with the inner tabs, but the outer tabs ...
-1
votes
0answers
30 views

Using analog hall effect sensor with a non-inverting schmitt trigger

I have an analog hall effect sensor (i.e. UGN3503UA) that I want to convert to digital by using a non-inverting schmitt trigger. The issue I am facing is that when I connect the output of the hall ...
2
votes
0answers
41 views

simulate a motor with resistor and inductor

I want to simulate a motor with a resistor and inductor. It means I want to connect a resistor and inductor to 1-phase or 3-phase instead of a motor. For achieving this goal I have to measure both ...
-1
votes
3answers
90 views

multimeter temperature accuracy

I have tried searching for an answer and looked online, but I'm just getting more confused. I have a DMM that measures temperature with a thermocouple lead, with a resolution of 1 degree C (shows 020)...
0
votes
2answers
30 views

Connecting an Arduino to Raspberry Pi

I'm trying to connect an arduino with 3 sg92r servo motors on it and an RPI with and lcd and the serial of the arduino connected to it. They are both connected to a power supply with 9v/1A and 5v/2....
0
votes
5answers
98 views

Why do you use a buffer when the whole point of op amp is to amplify signal?

This might sound like a dumb question but I just learned about buffers and learned that they have same Vin and Vout from the amplifier providing nearly identical Voltage source value to the next op ...
2
votes
1answer
45 views

Electrical circuit design questions

So I was wondering if there is any site or papers that has fun electrical circuit questions, such as placing the right components on a circuit to make it work, make the light dimmer/brighter by using ...
0
votes
0answers
6 views

Can I configure pairing for HC-05 and Arduino, and use the HC-05 without Arduino after? [migrated]

I have a system that is outputting data via its serial, and I need to relay that data to my PC wireless-ly. If I were to setup an Arduino and HC-05 at the system's side to relay the data, that would ...
0
votes
2answers
35 views

Hold-time Violation and timing diagrams

I was wondering what the output of capturing flop looks like, if there is a hold time violation from capture flop. Can anyone explain with a timing diagram?
2
votes
2answers
55 views

Triggering buttons on a remote with a Raspberry Pi

I would like to control my AC with a Raspberry Pi. My system is similar to this one, although it is an older model from 2004. Currently the system has a wired controller. There is no bluetooth, wifi, ...
1
vote
1answer
40 views

Zero-R Resistor on XTAL pins

Looking at the schematics of the STM32F4-Discovery board page 28, whose screenshot is attached below.. there is a Zero Ohms resistor 'R25' which is shown in the circuit with the Crystal. And there is ...
1
vote
0answers
23 views

Strange powerplane layering issue in designspark

I'm trying to order a 6 layer PCB from a fab but they are asking me to resolve an issue with the file and I'm a bit stumped on what to do about it. The second layer of the design I have designated as ...
1
vote
0answers
20 views

Signal Attenuation TVS and series resistor

This question is in regards to signal attenuation on high speed data lines like RS-485 (and any others as well). I'm new to the signal world, so please bear with me here. Are there some useful ...
2
votes
2answers
79 views

Why is my radio circuit not functioning correctly?

Ive built this circuit and it hasnt functioned correctly it picks up a humming which im pretty sure it is my power supply Can someone explain why this isnt operating as a radio? and maybe assist me ...
1
vote
2answers
1k views

Does anybody know what this IC is?

I tried different search keywords combinations, but I couldn’t find a datasheet, nor a hint of what this IC could be. Maybe someone who’s familiar with it could give me a clue. The IC is on a board ...
1
vote
0answers
12 views

How to calculate or show in matlab/pspice the DC component from a circuit simulation?

Based on Pspice I'm simulating this RL full wave rectifier That gives the next voltage and current output at the showed probe point The idea is to extract the DC component of the current or voltage, ...
0
votes
0answers
14 views

Proteus-How do I connect 5 inputs to get 4 outputs with a dipswitch?

I'm having trouble with making a schematic; I have 5 inputs and 4 outputs (dipswitch and 4 leds) basically depends on the first input (then on the other 2 inputs) which led is going to turn on. The ...
0
votes
1answer
21 views

Soldering Iron and Electrostatic Bracelet Connection

I have a DIY soldering station and I want to ground the soldering iron and I also want to use a electrostatic bracelet connector for the soldering station. Can you please help me how to connect the ...
0
votes
0answers
18 views

NRF24L01+ transmission problem

I'm trying to make the modules work on 2 arduino nanos but it just doesn't work.The serial monitor just prints random symbols instead of the "Hello".I tried everything I could find on the internet but ...
-1
votes
0answers
26 views

link dot matrix LEDs with tiny dc electro motor [on hold]

I wanna link every single dot matrix LEDs with tiny dc electro motor can you guide me how should I do that ? have any one done that before ? thank you all
1
vote
2answers
38 views

Shield grounding location for an STP cable in a balanced system

If a balanced source or driver is coupled to a differential balanced receiver via a balanced STP cable as shown in the hand drawn illustration below: in such case I have read that grounding the ...
1
vote
0answers
25 views

3s lipo battery 11.1 volts for rc planes [on hold]

I recently bought a 3s 11.1 volt lipo battery and a charger and a voltage tester, now when i plug the battery to the voltage tester its showing "2cs", and on the balance charger 2nd led is green , 1st ...
1
vote
1answer
29 views

Mosfet Gate-Source Zener

I want to confirm this circuit is going to work and ask how to calculate the zener voltage. The load is going to be driven by 30 volts, and the gate voltage is the same 30v, through an optocoupler.
2
votes
0answers
15 views

Hexagonal hatched polygons Altium

I'm recently trying to design a flex PCB. I haven't been able to find any specific tutorials on how to do this in Altium. But I did find Altium blogs detailing some of the best design practices for ...
0
votes
1answer
22 views

AVR DMX Transmitter outputs constant squarewave, not the form of a DMX packet

I'm using an ATMEGA328, with an external 20MHz crystal and fuses set by avrdude as -U lfuse:w:0x46:m -U hfuse:w:0xdf:m. I want to send DMX with it. Using the code ...
2
votes
2answers
25 views

R_on for inverter gate

What \$R_{on}\$ do I use to calculate the delay for an inverter gate? In my class we came up with two definitions of \$R_{on}\$, one for saturation and one for triode. Is there a certain mode I ...
0
votes
0answers
29 views

Circuit protection problem driving high side MOSFET continuously

I need to drive a high side N-channel MOSFET continuously. The circuit is essentially a passthrough, and the only thing I want to do is turn this pass through line on or off (usually if not always on)...
3
votes
3answers
78 views

Arduino analog input read peak-noise

I am using the NRF52832 and code it with arduino. I am reading A0 to get a signal from a sensor at 1m cable length. simulate this circuit – Schematic created using CircuitLab If I disconnect ...
2
votes
1answer
36 views

Common ground on a switch mode power supply

I've got a switch mode power supply and I have a question on the grounding of the PCB. Documentation on the PSU can be found here: https://docs-emea.rs-online.com/webdocs/1621/0900766b81621ef9.pdf ...
1
vote
0answers
29 views

Feedback signal consumed in VHDL

Hello I'm new with VHDL and I'm trying to implement a JK latch in VHDL using this RTL schema: Where the "latch_rs" is written as follow: ...
0
votes
1answer
30 views

Switch ON/OFF in MAX1709

I am designing a project where I'm going to use the MAX1709 step-up converter. There is a possibility to switch the converter ON/OFF with the help of ONA/ONB inputs, but according to schematic in the ...
1
vote
1answer
47 views

Noise quantification from sampled data

If a sampled voltage signal \$y[n]\$ is composed of its offset \$\bar y\$ plus noise \$x[n]\$; i.e. \$y[n] = \bar y + x[n]\$, are both following equations for the RMS value of the noise component \$\...
2
votes
0answers
48 views

High SNR FM demodulation

So I need to demodulate the FM signal from a sensor with highest SNR possible, at least 70-75 dB. IF is 10.7 MHz, max. deviation is 200 kHz but I can change those values if needed. Baseband signal ...
0
votes
1answer
61 views

PWM with ADC - ATMega16

I want to write code where I move the wiper of the potentiometer clockwise so it applies PWM on a pin, and when I move it counter-clockwise it applies PWM on another pin. I could do it with Arduino, ...
1
vote
0answers
40 views

Sideband Production

I am trying to understand exactly how sidebands are made. I've seen the math, but I'm looking for more of a component-level understanding of how they are made and what properties of the mixer ...
1
vote
3answers
68 views

P-MOSFET failures

simulate this circuit – Schematic created using CircuitLab P-Mosfet Datasheet The goal is that 5V (or logic high) appears on U3 when there is logic low on U4 and logic high on U2. That 0V (or ...
1
vote
1answer
25 views

Combining two led strips with separate controllers

Out of practice and have forgotten basic principles but would like to combine two led strips to one controller so they operate in sync. Have combined output from sensor into control box but outputs ...
1
vote
2answers
37 views

Connecting two wires to a DC 12v port on a controller board with 4 pads for a monitor

Sorry, the question was difficult to word. Basically I recently bought a controller board for a monitor and the DC cable I got wasn't correct. So until I get the right part, I just want to test the ...
2
votes
0answers
26 views

How to connect a MEMS Microphone Breakout - INMP401 to a RN-52 bluetooth module?

I intended to use a INMP401 (MEMS MIC) to capture audio and stream it via bluetooth using an RN-52 bluetooth module (RN-52). The RN-52 has inputs for differential +- signals. The INMP outputs ...
3
votes
1answer
48 views

Large dynamic range current sense 1uA - 100mA

I am looking at large dynamic circuits and came across an interesting project by ETH Zurich called the rocket logger - https://rocketlogger.ethz.ch/ I am a little confused by their current sensing ...
2
votes
1answer
38 views

Design ethernet switch for multiple devices on pcb?

I'm working on a pcb design with a Raspberry Pi CM module and a microcontroller with ethernet capacity. The goal is to connect the devices to the internet. I'm currently using a normal ethernet ...
1
vote
0answers
52 views

Charge a 12V marine/boat battery with AC

need to build a diode bridge to recharge a battery (car/boat type) from a boat engine that gives 12V AC. I thought of doing something like this: simulate this circuit – Schematic created using ...
1
vote
0answers
43 views

What's the actual cause of unbalanced combinational logic?

So far when I find timing issues, I try to pipeline combinational logic. It always works. Today, my Quartus Compilation Report show up -ve slack values. I double check it with TimeQuest Timing ...
1
vote
0answers
38 views

+/-10v Op-amp output with DAC

I'm using the OPA227 configured as a differential amplifier to generate a +/-10v signal from a DAC. In the diagram above, VREF = 2.048, and DACOUT swings between 0 - 4.096. The resistors values give ...
1
vote
0answers
14 views

RN4871 auto pairing

We are developing an application which needs the BLE Peripheral to be automatically paired with the smartphone when the smartphone is near the BLE Peripheral. We are using RN4871 Microchip BLE Board. ...
1
vote
0answers
35 views

Simplifying logic circuit

I've been trying to simplify a combinational circuit and wanted to know whether there was any simpler way of solving such questions. Do we have to find all the outputs and such or we can use a simpler ...
2
votes
1answer
25 views

MQTT Broker vs Server

I am trying to learn MQTT technology. What I understand so far, is that MQTT is based on a 'Broker' that does the 'Publish and Subscribe' of messages and topics. I wonder if it's another name for '...
0
votes
0answers
13 views

Half-wavelength coaxial balun: R=U/I=4R?

My quastion is according to half-wavelength coaxial balun 1:4. Why does the input current split into two equal parts (twice larger voltage and twice smaller current )?
1
vote
0answers
38 views

Connecting the secondary side of ignition coil to earth

I have an ignition system used for some application. During the testing I found that spark plug is producing EMI due to spark occurrence and high voltage is traveling through the wire. So to ...

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