# All Questions

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5 views

### Is EMC compatibility required for non-consumer devices?

I'm working for company X on some devices for smart building (lightning, energy management etc). These devices are owned by a company X and installed in other companies buildings (shops, restaurants ...
5 views

### How to buffer balanced (XLR) audio signal while forwarding phantom power

Background: I have a condenser microphone, which requires +48V phantom power from my mixing desk. The microphone has a source impedance of "<200 Ohm" as per manufacturer. As you may ...
3 views

### Replacing 10uF tantalum capacitors with X7R in ADM2587E circuit

I'm working on some device with isolated RS485 based on ADM2587E transceiver with integrated high frequency isolated DC/DC converter. This IC is a bit tricky if you need low EMI, because DC/DC ...
9 views

### 7E8 to 7FH on the CAN bus

I am new to the field of automotive electronics and am currently trying to understand the working of the CAN bus. I understand that when we connect a CAN bus logger to the OBD2 port in a car we will ...
16 views

### Controlling 3 wires at the same time

Can I controll 3 wires at the same time by transistors, if I connect their bases?
9 views

### Reliability Testing of Complex circuit using Arrhenius Linear Acceleration Model

I am interested in conducting accelerated life testing on a complex amplifier PCB with multiple amplification and filter stages. Doing some research and reading I have identified the UG-311 Analog ...
25 views

### How to increase the output current of a dual supply (virtual ground) circuit

I need to build a dual 5 volts power supply capable of 200mA output current. I've seen designs using TLE2426 and BUF634, but they cost too much for my project. Is it possible to use a simple OpAmp ...
11 views

### Choosing the right Over-Voltage protection circuit

TLDR : Ideal supply voltage of a device is 12v DC (labeled near jack). User may mistakenly provide anything from 3 to 24 DC (or maybe 220v AC). how to protect the circuit against Over-Voltage ? how to ...
12 views

### How Prepreg types and number of plies affect mechanical and thermal properties of the PCB

What are advantages and disadvantages when using a single ply of 7628 type prepreg as compared to say 2 plies of 1080 or a similar prepreg. I'm primarily concerned about any mechanical and/or thermal ...
27 views

### Scale dB SPL based on mic sensitivity

I have a measurement performed using GRAS 46AE microphone calibrated at 410mVrms at 114dB (250Hz). I have a .wav file recorded and performed stft and obtained the magnitude. Now I would like to scale ...
44 views

### How many UART lines should I connect between module and host

I have an LTE module (quectel bg95) that gets AT commands from a host esp32 (esp32-wroom-32ue) via a UART connection. And in the ESP documentation AT manual to send AT commands I should connect: RXD, ...
72 views

### What ASIC/MCU is in my keyboard?

I disassembled my unbranded USB keyboard to find out what ASIC/encoder/MCU is inside. The chip is (as expected) covered, like the following example: How to find out which chip is underneath?
43 views

### Basic voltage/current regulation with MOSFET, cannot fully close current controlling MOSFET

I tried to decrease value of Rg resistor on the gate of the MOSFET (the one on the right) but then the MOSFET does not open enough and i get low currents trough it, i have this setup on breadboard and ...
26 views

### Transconductance value in LTSpice

I am trying to work out how to specify the transconductance value or Kn for LTspice. I have a part I can't find a suitable model for so I'll need to create one. I've tried this before and got values ...
24 views

### Find my Amplifier Voltage Output to match my Sub Rating

I have two amp with a sub connected to each one and I was wondering how to check what's the wattage output to make sure I don't blow my subs, since they are two exact same pair I'll just use one for ...
40 views

### DPDT Polarity Switch

I am trying to connect a USB relay to actuator, so when I press button 1 , motor goes up, when i press button 2, polarity is switched and motor goes down. I am trying to achieve this with a DPDT relay....
43 views

### Looking for the solution for very close board interconnect using pin headers

Here's how it looks like The small board with potentiometer is mounted above another board. I used Connfly 1.27 pitch headers with 1.7 mm body height, cutting its body to approximately 1 mm. But ...
43 views

### The purpose of solar MPPT?

I already know what a MPPT is supposed to do. It's basically a buck/boost converter connected to a solar panel that finds the ideal power output by changing (boosting or lowering) the voltage of the ...
16 views

### Wiring diagram & data sheet for a BLDC motor controller for electric scooter

We are working on an electric scooter (moped) project. We have added a PCB to it. The scooter is using a generic BLDC motor controller. Can someone help us with the data sheet or wiring diagram for ...
88 views

### Is scavenging parts from consumer electronics for own commercial products, a good idea?

I have a product that I'm trying to bring to market. For prototype I pulled a camera PCB from an old webcam. It so happens that because my volume of production is low it is actually three times ...
80 views

### Diode Transistor Logic gate

Could anyone explain me the function of that part indicated by the arrow below, and what happens if we operate the circuit without that part.
30 views

### DC step-up converter, slecting 2 different Vout with SPDT switch

I want to modify a DC-DC step-up converter that uses a single potentiometer that sets the voltage to use a single SPDT switch where I can select the output voltage during operation without turning the ...
14 views

### TPS3619-33 (Backup-Battery Supervisor) overdrawing current at the VBAT path after a few runs

I've been having a few problems in integrating the TPS3619-33(Backup-Battery Supervisor) into a product that I've been working on for quite a while. After installing a new TPS3619 into the board after ...
40 views

### Does a TVS diode provide adequate protection for an LCD screen powered from a car 12V outlet?

I fitted an LCD screen in my car and I want to power it, along with other devices, directly from the car's battery. The other devices are specifically designed for automotive use, but the screen, a 10....
53 views

### Voltage follower output current

We know that voltage follower will have a nonzero output current. How do I solve for this value? Let's say I am using an LM358 op amp to implement the buffer (unloaded), do I just use the Output ...
22 views

### Diagnosing short inside Nintendo Switch [duplicate]

My Nintendo Switch suddenly wouldn't turn on or charge. Nothing on the screen, no reboot/reset trick I have tried worked. I often used a normal USB-C instead of the official charger, which might have ...
57 views

### STM32 gets stuck in While loop

I am new enough with STM32 programming. But now I am working with a environmental parameter monitoring module based on STM32F401RE development board. Now I am facing a strange problem. When I try to ...
27 views

### tag replication circuitry

I found a question to practice so I can increase my experience in RTL design. I am trying to come up with a generalized design which can support all these requirements. Here are the details: Black-box ...
87 views

### The effect of grounding a simple circuit?

Suppose I have a simple DC circuit consisting of a battery of voltage V (no internal resistance assumed), and a resistor (resistance R) connected in series by conducting wires. Because the wires are ...
29 views

### How to calculate the maximum Torque for a PMSM Motor?

I have a cheap BLDC/PMSM Motor from Ebay. I don't have any further Information, only a sticker: "A2212/10T 1400KV". I connected my oscilloscope to 2 phases of the motor and I have seen that ...
34 views

### How to calculate C for an AM demodulator?

I have read this equation from Savant's book that is used to calculate the capacitor for a demodulator: I've tried to calculate my circuit with this equation, but it didn't work. Then I tried to ...
45 views

### Input protection for instrumentation amplifier

There were a few concepts mentioned in the Input Protection Basics from A Designer's Guide to Instrumentation Amplifiers, page 5-5 that I don't quite understand: Why direct transient to power supply ...
52 views

### Inductor time variable current

At t0<0 the current through the inductor was 0. simulate this circuit – Schematic created using CircuitLab At time t0 we introduce a current source and a resistor to the solenoid The current ...
22 views

### What is the setup/hold time of the RMII receive interface of the TI DP83630 phy chip?

I'm interfacing the TI DP83630 phy chip to FPGA over RMII interface and need to write the timing constraints. I'm having difficulties interpreting the receive interface setup and hold time from the ...
29 views

### Using Quickfield LabelMover to extract specific local values at coordinates

Quickfield Student Edition I've attempted using Quickfield's LabelMover Serial Analysis to automatically get local values of interest at a set of different specific coordinates, but I couldn't find a ...
36 views

### spectrum of trapezoid with unequal rise and fall times

What does the spectrum of a trapezoidal waveform look like when the rise and fall times are unequal?
59 views

### Maximum rate between ADC-FPGA link for Igloo 2 vs Max 10

An ADC has a source synchronous output interface and is to be interfaced with an FPGA. The ADC can communicate using single ended CMOS, DDR CMOS and DDR LVDS. How do I know what is the fastest rate ...
44 views

### Split voltage interconnection

I have these circuits: Their goal is to protect the +vcc and -vcc pins of an opamp. They limit the voltage to +30 V (-30 V) and 25 mA in normal conditons. The 1200 ohm resistors act like 25 mA load ...
64 views

### How to make second sinusoid look like first one?

I am using Multisim 11. I am making doppler emitter. I want the red square wave become a sinusoid and to be like the green one: This is how a part of scheme looks like: Red "sinusoid" is ...
26 views

### Bi-directional Logic level converter/shifter

I'm trying to build a bi-directional Logic level shifter, to convert 1.8 v to 3.3 v. I'm having difficult choosing/finding a n-Channel MOSFET that will work with the voltage levels (I will not be able ...
20 views

### VHDL CODE Error (12006): Node instance “ ” instantiates undefined entity “ ”

I am having issue with the following vhdl code. ...
30 views

### mush instead of signal stm32 nucleo-l053r8

Generating a triangular signal. The "printf" line is commented out. If the "printf" line is uncommented, instead of a signal, mush. How to fix it? (stm32 nucleo-l053r8) ...
21 views

### DALI addressing of multichannel driver

I am trying to set up an Arduino as DALI-Master for multiple light sources. As a starting point I made use of this excellent project. There is also a gitpage with a good overview of the available ...
100 views

### Being scammed for buying IC from Aliexpress [closed]

please could someone identify this chip? I was ordering IC MCP4921E, but I got this IC instead
42 views

### Motor resistance and inductance

When I want to model a electric motor as a plant, the transfer function is: $$G(s) = \frac{1}{Ls + R}$$ And this can be used, to automatically set the optimal current control gains of a PMSM motor. ...
47 views

### How come usb power banks tend to be much larger than cordless tool batteries?

I have a 10000mAh battery pack for charging phones/tablet/whatever but I also have some cordless tool batteries which can be used in an inverter to power a usb charger similar to the power bank. The ...
40 views

### Microcontroller randomly resetting when BLE module is enabled

I'm new to programming on microcontrollers and I'm currently working on code written by another person who I unfortunately can't contact anymore. The issue I'm facing right now is an STM8L052R8T6 ...
49 views

### DC motor gets stuck when it hits the end of its track

EDIT: Solved, I'm not sure how to mark it as solved though I don't really know what this phenomenon is called so if this question has been asked before I apologize. Basically I have a dc motor and it ...