General Q&A about the design and function of electronic systems, electric power systems and infrastructure, their theory, and tools specific to those fields. Read these guidelines before posting.
I've heard that a bootloader is code that runs on a microcontroller, and is used to get your application code onto the micro. How does that work? Is there anything special that needs to be done to...
What value pullup resistor should I use for a pushbutton connected to a microcontroller input? I've seen values from 1 kΩ to over 100 kΩ. Some references just say to use 10 kΩ because it's a "goo...
The question: Is there a way to convert from triple-phase 208VAC to single-phase 208VAC? Background: Hi everyone, I am stuck on a project I'm working on. I'd like to convert 208VAC (three phase,...
Recently I have heard this opinion from experienced engineers when discussing PCB design software. The common opinion was that Allegro and Altium are supposedly professional programs whereas Eagle ...
I have no experience designing for Intrinsic Safety (IS), but need to do that now. I have read thru IEC 60079-11, which seems to be the relevant standard for my purposes. The board I need to desi...
Usual values used in doing electronics/power supplies are almost always round numbers: 5V 12V 28V 48V 60V I understand that in some cases IC's are built to accept the voltage directly com...
Although I have done multiple PCB designs which passed FCC and CE equivalents using the MCU's/Multiple MCU's, I have a doubt about how to approach the high speed design using FPGA SoC - main thing ...
We see schematics of varying quality and conventions. What is good and bad? What are the rules and conventions for drawing good schematics? What matters? What doesn't? This question is about sch...
I am looking at various DC/DC converter topologies for a power system I am designing. The most suitable topology for me is one that can perform both step-up and step-down functions, so I am looking...
The premise In a recent video by the pop-sci channel Veritasium, the concept of the flow of electricity and energy transmission in a circuit was discussed. In that video a thought experiment is pr...
The circuit above is used to control a 240W ceramic heater by means of a PWM signal at 30Hz, generated by a microcontroller, with 5V logic. The input is a standard 280W AC-DC external power adapt...
I am analysing a pulse transformer which is required to transfer below communication protocol pulse from primary to the secondary side. The pulse duration is 32 μs and off time available to reset t...
When writing firmware in C for a microcontroller, how can I directly access a memory location such as a hardware peripheral register, given its absolute address? Is there a way to do this safely an...
Hello. I have a grounding problem on my acquisition system. I have read many articles, app notes and whatever but still could not find a convincing solution for the topic. The acquisition system is...
I'm designing a high side current source that can be controlled with a Digital-to-analog and can source up to 100mA with voltage supply up to 36V. By high side I mean one side of load will be alwa...
As we know there exists numerous different kinds of PCB CAD software. The big ones seem to be Eagle, KiCAD, Altium, OrCAD, Solidworks, DesignSpark and probably a few more. When it comes to mechani...
First I noticed that clock begins before chipselect gets pulled low on SPI. After eliminating potential sources I started to suspect the scope. I connected all 4 channels to function generator at d...
One of the ceramic capacitors that I've found(link to the capacitor) specifies the following characteristics at 10 kHz: The difference in value is quite significant, almost 100 fold. Which grap...
I was watching a video from EEVBLOG about bypass capacitors, and he presented a theory that randomly connecting different values of capacitors in parallel can create unexpected impedance spikes: ...
Assume I'm a complete beginner at RF. Is there a way to measure return loss of an antenna, in such a manner that I can reliably reproduce the measurement later on? What I'm talking about is produ...
I know that in transistors there is base, collector and emitter, and in FETs there is gate, drain and source, but what is the fourth grounded connection opposite the gate in this NMOS circuit?
Signal characteristics are: 0 to 3.3V span 0 to 100Hz range( there will be noise superposed on top with unknown characteristics) Output resistance Rout=4700 ohm I want to sample that with a...
I saw that this PCB socket: Is marked as pressfit for non-plated holes. However, can it be used with plated holes as well, or will it damage the plating inside?
RF novice here. If using a superheterodyne receiver for the purpose of FM/FSK modulated signals, I'm wondering if the location of an optional automatic gain control (AGC) circuit is always placed o...
I have a PIC32MZ2048ECG064, a 64-pin 32-bit microcontroller with 512kB RAM. This is not enough for my purposes, I need to extend it by at least 32MB, preferably 64 or 128. I believe this means I ca...
Differential pairs, such as for ethernet or a CAN bus, can be designed to be loosely coupled or tightly coupled. For a loosely coupled differential pair, the odd-mode and even-mode impedances are ...
I have recently finished designing a buck-boost converter for a job that uses a split (+/-) input power supply. Load power is taken equally from both positive and negative input supplies and, the ...
I'm supporting a piece of legacy hardware that routes the SPI bus through a set of headers to an expansion board. Since the expansion board doesn't actually use the SPI bus, we simply ignored the ...
I have seen many engineers talk about ESD protection but I had never seen its effects myself. I made many small DIY projects and I have used bare hands to touch ICs and their pins,but nothing got d...
I need to design a simple flyback converter like this: - I want to control duty cycle from another circuit such as an MCU but, I'm unsure how to proceed. My requirements are: - Input voltage 125 ...
The particular IC I ran into this issue with was DS3231 RTC. The pin configuration shows: However, the datasheet specifies To my knowledge, 'N.C' appears on ICs when it is decided to use a cer...
I can't get my CAN bus application (ISO 11898-2, classic "high speed CAN") working and I'm receiving various CAN error frames. These error frames manifest themselves as sequences of 6 bits with my ...
I have seen pi-filters using chokes, ferrite-beads, and plain inductors as the L-element What are the main differences between them? when use one or other?
I have a handheld ARM Cortex M based device, which has a USB input port. The product is battery powered and there is no metal chassis. We are going through CE testing, and are having ESD issues a...
Which are the parameters I should looking for when picking a flyback diode to be placed across a generic coil, such as a relay? That is: a coil with plain on/off functionality, for example a 24VDC ...
Simple thing that I realized I should know but do not -- when is an MOV preferable to a TVS diode (with some associated network to really make it work, in both cases)? Is it even something to routi...
What benefit has a differential amplifier when measuring the signal from a sensor that is remotely located such as in this example: - Why can't I use an arrangement like this: -
My scenario is this: radio equipment controlling an overhead crane inside a steel mill. Specifically it is used for transporting melting pots. With the current, unfortunate installation, the antenn...
I was looking at different transistors, especially MOSFETS and I saw that N type MOSFETs seem to be way more popular to be used in circuit design. Is there a reason for that, or am I mistaken?
I am trying to analyse what is controlling the load current in the below Darlington configuration. Is it the base current of transistor Q3 which is controlling current through R14 / emitter curr...
One standard used for spacing conductors based on voltage is the IPC-2221. This standard differentiates spacing requirements for inner and outer conductors. Does the IPC minimum separation betwee...
I am designing a PCB with somewhat limited space. To save space, I am placing some vias on component pads. However, I am not sure if this is a good practice in PCB design. As far as I understand, t...
I was hiking around the Berkshires in western Massachusetts yesterday, and came across this metal panel where some power lines were crossing a ridge: The panel is a few meters wide, and appe...
Modern CAN transceivers like MCP2561FD that support CAN FD with high baudrates come with an optional feature called SPLIT, which is to my understanding a reference voltage output pin used to give a...
When using through-hole ("THR") connectors on a multi-layer PCB, I frequently notice problems with the ground pins, when these are connected to the ground plane(s) through various "thermal relief" ...
In all descriptions of how (non-FET) transistors work I've seen, there is an inherent symmetry: There's either an n-doped layer between two p-doped, or a p-doped between two n-doped, and the descri...
Whenever declaring a variable in C outside a function at file scope or when specifying it as static, it gets assigned a life time known as static storage duration. Meaning it will be accessible thr...
Hi guys so recently i was looking for a mosfet and a gate drivers and between a lot of their specification the rise/fall time and Turn-On/off Delay Time sometime it called propagation. My question...
[Disclaimer. This is not for an academic class. I'm self-studying.] I’m reading an introductory book on DSP for audio and computer music [Steiglitz 1996, ISBN 0-8053-1684-1 p. 287]. One of the ...
A taper pad is a resistive attenuator that maintains impedances on both ports and provides a specific amount of gain-loss ($A_{12}$): - I have derived formulas for each resistor (that I know to ...
