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35 views

What sensors and how many do I need to detect sounds and ultrasounds until 1MHz [on hold]

I need to detect and list all frequencies with an amplitude over a threshold, any detailed answer is welcome. Precision for range : Lower bound can be as low as 10-20 HZ, but my emphasis is on ...
-2
votes
0answers
50 views

Bldc motor and power usage [on hold]

I'm using bldc 5hp (4.1 kw) 48v 2500 rpm motor how much battery capacity (in Ah) is needed for it to run for 5 hours Continuously l (How much capacity of battery needed to drive above motor for 5 ...
0
votes
1answer
78 views

Poor Man's UPS for a Microcontroller

I'm planning to create a Control Box for my Home Solar System which will involve using a microcontroller (STM32F103C8T6) as my control system. This uC will handle my current sensing for power ...
0
votes
2answers
48 views

Time-invariant system question

I seem to struggle with the notations and concepts used in signals & systems. The book states, given that x2(t) = x1(t-T), x2(2t-5) is equal to x1(2t-5-T). This might be a dumb question, but ...
15
votes
3answers
5k views

What does the “capacitor into resistance” symbol mean?

I can't understand the circled symbol and didn't manage to google it. It looks like a variable resistance and a capacitor. What does it mean?
7
votes
2answers
57 views

Is one big via better than multiple small vias when changing power traces and ground between layers?

I'm confused about the via placement in power traces either to change layers as part of routing the main supply or to get to component pins from a layer different to where the power trace is located, ...
0
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0answers
34 views

How does your country evaluate power quality (standard procedures)? [on hold]

How does your country evaluate Power Quality? Do you have a standard procedure available online? I'm working on my final engineering project regarding the development of a PQ monitoring, assessment, ...
0
votes
0answers
47 views

Is VBUS sensing necessary for USB on a self-powered device? [duplicate]

I'm currently designing a self-powered PCB with a STM32L432KCU6 and USB. After having done some research, it seems that it is necessary to connect the VBUS pin for detection purposes. However, is it ...
0
votes
1answer
85 views

How could this circuit be reduced to first order low pass filter?

I was told that the bottom half of the circuit wouldn't matter due to having a corner frequency being significantly higher compared to the top half, or due to time constant (somewhere along this line.....
0
votes
1answer
92 views

Can resistive traces be created on a PCB?

I'm assuming that copper traces on a PCB have negligible resistance. Is it possible to put a trace on a PCB that has some greater amount of resistance? The amount of resistance would not need to be ...
0
votes
0answers
40 views

Clarification on adding capacitors in parallel

I have a 5 metre strand of WS2812B LEDs, at 18W per metre. I also have a 120V to 5V-30A power supply I plan to connect them to. The data pin will be connected to (for now), a PWM pin on an Arduino ...
0
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0answers
39 views

low power high efficient unregulated ac/dc converter

I am needing to graph an ac voltage onto a computer screen. The voltage is proportional to the moisture content of soil. The ac voltage is close to 0 when the soil is extremely dry and around 100 vac ...
0
votes
1answer
67 views

What does an antenna “matching transformer labeled 75 ohm to 300 ohm” really mean?

Shouldn't it be the other way around? (300 ohms to 75 ohms) 300 ohms coming out from the antenna wires to 75 ohms coaxial cable? Where does the 300 ohms comes from? is it because most antennas use ...
0
votes
1answer
77 views

How to make 1uA consumption on Attiny13a?

I'm measuring my standalone Attinty13a (internal 128kHz) current consumption with li-ion accumulator (3.7v, 220mAh). Here is my schema and code: ...
0
votes
1answer
38 views

Problem Powering 13.3 inch LCD Screen with 3.7v Battery

I have been working on a project that involves running a 13.3 inch lcd screen off of a rechargeable battery. I bought the lcd screen and controller board listed below and verified that it was working ...
1
vote
0answers
21 views

DALI deterministic commissioning

I am currently looking into setting up a DALI system with my own programmable DALI master and (over time) a multitude of DALI (LED) lights. The general idea is to use an already existing DALI python ...
0
votes
0answers
33 views

200-400 mah lipo 3.7v to 1.5v with best possible efficiency [on hold]

how do i step-down 3.7v 400mah lipo to 1.5v @ < 100ma as efficiently as possible?
0
votes
0answers
40 views

True zero offset current DAC

Is there a current DAC which has 0 current (< 1 nA) for an input code of 0? I am driving an LED, so would it make sense to use bipolar supply rails (where a negative output would reverse bias the ...
0
votes
0answers
8 views

Pulsing issue in HV push-pull MOSFET switch

I am trying to pulse a high voltage push pull MOSFET switch HTS-201-03-GSM (behlke make) to drive a non inductive resistor load. The low voltage and high voltage side is galvanically isolated to 30kV. ...
0
votes
1answer
41 views

Adapting two-way radio tactical throat mic (laryngophone) to cell phone or laptop

I've ordered one of these: https://www.amazon.com/gp/product/B074Z1LDY2/, a tactical throat mic (and earpiece speaker) which is intended to be used with Kenwood two-way radios (and other compatible ...
0
votes
1answer
27 views

Is this circuit for Piezo Transducer and corresponding resistor values correct?

I want to drive this piezo transducer (https://www.mouser.com/datasheet/2/670/cpt-9019s-smt-1310960.pdf) at 3V and 4kHz with STM32F0 microcontroller. This is a follow-up to my previous question (Is ...
1
vote
0answers
24 views

How to receive multiple RS-422 inputs concurrently and combine their sentences into a single file?

I'm trying to gather RS422 signals at 4800 baud and 9600 baud from 5 different sources. The sources are all constantly streaming, but I want to log all five of them in a single place. What would be ...
1
vote
0answers
32 views

Drift in output voltage of load cell

I used one of these scales and after a few months the reading started drifting up: after hitting tare to get to zero, the reading would show 2 grams, then slowly go up to 10 g in one minute. I ...
-3
votes
0answers
48 views

The Current Number of CPU and GPU Cores, Going Forward Time [on hold]

I have a thought on why, the number of Cores in CPU in the consumer markets are always the same ? Core pairs like below; Intel: i3 (2C, 4T), i5 (4C, 8T), i7 (6C, 12T, and other variants), i9 (8C, ...
-2
votes
1answer
30 views

Verilog Case Statement Help

Hello I am having trouble with the syntax for case statements. I am using Verilog to make a counter using a 7 Segment Display. I keep getting an error on the following line. ...
1
vote
1answer
90 views

Solder won't flow into metal contact

I want to solder a wire onto this metal contact, but the solder wont flow into the contact. I have my soldering iron on 300 degrees Celsius using a chisel tip using 60/40 rosin core solder. I sanded ...
0
votes
1answer
18 views

Adjustable undervoltage switch module [on hold]

Is there any reade-to-use solution for adjustable undervoltage switch? I have a very simple circuit consisting of: Battery (3.6V) > Battery charger module (protection of deep discharge of 2.5V) > ...
1
vote
0answers
69 views

What is the meaning of 1N, 2N, 4N, 6N (and probably others) in the semiconductors name? [duplicate]

There are many discrete semiconductors with names like 1N4148, 1N4007, 4N35 or 6N137... And they can be produced by many manufacturers. So it looks like it is not a marketing names. Looks like 1N are ...
0
votes
1answer
68 views

Feeding microcontroller and linear actuators (motors) with the same power supply

I have already made a diagram using a motor controller. The details of the actuators are: Input voltage: 12VDC Max Load: 750N(168.607lbs) Stroke Length: 16 inch Travel Speed: 12mm/s Duty Cyle: 25%. ...
0
votes
0answers
25 views

si4713 in I2S mode

We have been trying to run si4713 chip on i2s mode, but no success so far. Has anyone run this chip in i2s mode ? Can someone share PCB design for this ? Here is the reference doc Adafruit Si4713 PCB ...
0
votes
0answers
21 views

Using Verilator for Co-Simulation

I want to simulate a home-brew CPU written in Verilog along with some "peripherals", like a "VGA monitor" and a keyboard, written in, let's say, Javascript. From my understanding, here's some possible ...
2
votes
2answers
36 views

Avoid voltage peak / static discharge freezing arduino

I am building a speed-testing stand for electric wheelchairs with an arduino nano + rotary encoder. The wheelchair is put on cable caddies, which turn the rotary encoders via a belt. The setup itself ...
0
votes
0answers
24 views

Finding SNR from a Matrix Equation

So, my question is really straight forward. If I have a equation like this, $$Y = HX + W $$ where, X is the source signal vector, H is the channel gain matrix and W represents AWGN vector. I would ...
2
votes
1answer
55 views

Repurposing PWM output for D- of USB

I'm currently designing a self-powered PCB with a STM32L432KCU6 MCU on it. I want to use USB, but D- is already used for a different purpose. According to the datasheet, D- and D+ have to be ...
0
votes
1answer
39 views

Charge-Pump Cap Power Dissipation in Voltage Converters

Here https://www.maximintegrated.com/en/app-notes/index.mvp/id/725 and here https://www.analog.com/media/en/technical-documentation/data-sheets/ADP3603.pdf The same calculation for the power ...
0
votes
0answers
13 views

Serially Programming STM32 Using ESP32

I have a PCB on which sits an ESP32 and STM32. I want to use ESP32 to perform OTA on STM32 and for that I would like to serially program the STM32 using ESP32. I have a serial connection between PA9 ...
5
votes
2answers
241 views

Insight into cavity resonators

Modes of a waveguide As shown in the link above, they show how these modes work for various values of m, n, and p. However, where is the antenna/ source of radiation placed within the cavity? From ...
0
votes
2answers
40 views

Interconnect 5v - 3.3v

Is this correct to connect 5v outputs and 3.3v inputs ttl logic via an open drain transistor and an internal pull-up resistor on the digital input? I suspect the 5v part can influence to the 3v part ...
0
votes
0answers
27 views

Which is best board or microprocessor for high frequency sine pwm generation for motor drive [on hold]

I'm building variable frequency drive for induction motor based on sine PWM modulation technique. I developed a code for atmega2560 which provided a decent 3 phase waveform. But the frequency is ...
0
votes
0answers
34 views

How to interface between arduino and commercial triac control board [on hold]

Question: How to interface to the board described below. Context I am working on some new LED-lighting for my home. I want to repurpose the human interface from the existing installation – a wall ...
0
votes
0answers
30 views

How can I read a Calypso CD21 contactless smart card? [on hold]

I'd like to read a Calypso contactless smart card, model CD21 by STMicroelectronics, and dump its raw content, but my NFC ACR122U reader doesn't even detect the card. Can that type of card be read/...
0
votes
1answer
89 views

Is running two voltage regulators in parallel safe?

Components Battery (7.5V 6A Max) D24V25F5 (5V 2.5A step down) U3V50F12 (12V 5A step up) Raspberry Pi 3 (5V 2.1A-2.5A) Motor (12V 3A stall) (Using H-Bridge) Would the setup be suitable? I much ...
0
votes
1answer
41 views

What transistor setup to use for level shifting to create a logic ENABLE signal (for DC-DC converter module)

I want to create an ENABLE signal driving a Murata OKI-T/3-W32P-C DC-DC converter, where the P stands for Positive Polarity of the On/Off Control line: the line has an internal pull-up, which means ...
0
votes
1answer
28 views

AC Simulation in Power supply simulators

I would like to design a boost converter using LM3481 from texas instruments. To de the job, I have selected TINA TI circuit simulator, where the average model of LM3481 is given. So I have used this ...
0
votes
1answer
49 views

Ultra Miniature Coaxial connector what does 50ohm stand for

In my current project I designed a PCB board for the ESP8266EX chip. Instead of making an onboard antenna, like in the datasheet described, I have placed this connecter. The goal is to be able to ...
-2
votes
1answer
32 views

Ultrawide band bandpass filter

Please suggest how to design ultrawide band bandpass filter in ADS (Advance Design Software) using distributed Microstrip transmission lines.
0
votes
0answers
31 views

Wireless i2c communication [on hold]

I have an existing device that communicates over a cable via i2c. I want to remove the cable and make the device wireless. Is there some sort of RF between Arduinos/Teensy 2.0s that can be ...
0
votes
2answers
71 views

NTP Time calculating

I have this code and i use in my device. ...
0
votes
1answer
30 views

Audio jack adaptor

Can I connect two headphone to each other using a female to female connector and setup communication between the headphones?
0
votes
1answer
46 views

crystal stability gone wild on higher speed microcontroller

I made a board with AT89LP52 (higher-speed brother of AT89S52) and at the crystal connection I used a 22Mhz crystal with 5pF NPO ceramic caps grounded. The circuit itself works along with the ...

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