1. M

    [Please Help] Polarity Protecting a Jimmy-Rigged "TronicalTune Plus"

    Hi all! First post here, please excuse the lengthy read and thanks in advance for any help you can offer. For background, I'm a hobby-level tech nerd, mostly with audio equipment though... tends to be a bit modular, haven't designed many circuits. Super handy with a soldering iron, quick...
  2. IgnacioMorac

    Can I Turn On an XBee, ATMega328, RTC DS1307 and Catalex microSD adapter

    Hello partners I am an engineering student and I am doing my graduation project. I try to send information from the Photovoltaic Panel to the computer. In order to do this, I made a design of a circuit that can measure the voltage of a panel that is generating between 25 and 44 volts. This...
  3. jm_sanz

    Estimating junction temperature from top case of SMD MOSFET

    Good afternoon to everybody. First post over here! :D I am working on the estimation of junction temperature from top case temperature measurement. I have seen that manufacturers avoid the characterizing the molding this resistance which is crutial for this purpose. From now on I will take...
  4. S

    Shocked by beginner circuit kit

    I was trying to visualize a beginner circuit problem on my breadboard and I plugged in my circuit, touched a resistor and got a nasty shock. I am a cs student playing with circuits to build some logic gates so I really am a complete beginner. Why did this happen? How can I prevent this from...
  5. HazenAL

    Minimal Parts LED driver

    I want to design a LED driver that is compact and uses mostly SMD components. It will run 1 LED at 700 mA and 3 V, and be user dimmable with a PWM signal (0-100%) as well. Additionally, It will plug into a USB port to run off of 5 V. My question is that which design will yield the least amount...
  6. Y

    What is this component?

    Hi everyone! I'm wondering what component is this? It is crunchy when you turn it like a sand inside and i think it needs a replacement. It doesn't control the power output properly. It is the two large object near the red led (one of it is crunchy)
  7. T

    Need help finding right parts to power 3.7V 8000mAh battery to charge via USB-C + output DC 12V

    I am trying to power an Odroid C4 board right now. Part: 1. Using a 3.7v 8000mAh Lithium battery (https://www.amazon.com/8000mAh-7565121-Battery-Rechargeable-Connector/dp/B07S84TSFH) Expect: 1. Need to be able to charge the battery using USB-C 2. It needs to output DC 12 V to connect to...
  8. T

    Lighting Project Advice

    Hello, Im planning to do a very simple project but getting quite confused about where to start as I've done parts of it before but not brought everything together in one piece. Any advice on where to start would be great and I can expand my knowledge. Project Aims Simply put a box containing...
  9. E

    Buck Converter from 48V to 5V

    I am using Arduino and Controlling FAN which works on 48v. so i am using 2 power supply smps in my design. One for Arduino that 5V smps and another for FAN that is 48V smps. I want to use single power supply in my design that is of 48Vdc. I was looking for a buck converter that will take 48V as...
  10. E

    Feeding load with two 220V AC power supplies to reach uninterrupted power supply.

    As shown in the diagram, I am trying to connect two power sources to load. The battery source is for emergency in the case of power outage of the wall source. I want the switching to be instantaneous with no interruption of power. What is the best solution to this problem? Is there a board...
  11. froilan.1

    Speaker Power Specifications

    Hey guys. I'm newbie to this forum i don't know if this is the right forum if not pardon. I'm here to ask what is rhe specifications of this speaker i can't see specifications at the back but i taken some pictures i am planing to rebuild this one. this speaker is from my deceased father. thank...
  12. Dinesh6252

    Can i use a 13s bms for a 7s project? And how?

    I have a 13s bms laying around and I want to use it as a 7s bms, is there a way to do that?any suggestions would be greatly helpful.
  13. jcarlson023

    DC Switching linear regular design question

    Hello, I am fairly new to electronics design (I have a mech e background), and am designing a board that requires dropping 12v to 5v with a large current requirement (up to 8A@5V). In a bid to save on BOM, I took a shot at creating my own design vs buying one off the shelf, using the...
  14. Genosphere

    Guidance for Electrical Power Project - 4160V motor needs starting (simulating utility company?)

    Hello all, this is my first post here so be gentle. Currently enrolled in an Electrical Engineering program and finally finishing up next year. I have 7 years of avionic and airframe experience in the aerospace industry and more hours around automotive junk. I have worked plenty with coding, CAD...
  15. L

    How do i implement a dual role power system via a USB-C port for my custom PCB.

    I currently have a custom PCB design using the PIC16F1937-CN. The custom circuit gives an output voltage via the usb to an external device. I would like to charge my circuits battery with the same usb port which is currently not the case. It has another port for charging the device. What design...
  16. A


    hi to all i have a question about the AM signal power in am modulation in attach file i have derive the power of am signal but ther a term <m(t)> is the mean value of message i can ignore this term generally or in the case where the m(t) have zero offset? thank you George
  17. S

    RMS Voltage change of MLCC Capacitor with Frequency

    Hi all. So I know that the impedance of the capacitor changes with frequency. However, stumbling across a document by KEMET and their new stacked MLCC capacitors which allow higher ripple current, https://www.mouser.co.uk/datasheet/2/212/1/KEM_C1105_KONNEKT_KC_Link_C0G-1855982.pdf There are...
  18. J

    Current control for a battery charge

    How can I control the current that is supplied to a battery? I need to balance current consumption to avoid some parts of the system run out of power. My system is described in the attached file. I have a 12V input which goes into a Boost regulator to get 48V. Those 48V are used to feed a...
  19. T

    Circuit Analysis

    For Question 2.1, is the power 500W or 100W ? Do we need to apply the passive sign convention rule for power in whatever cases? Also, i’ve Learnt that we can check answers by balancing power in a circuit. But the power in this kind of circuits don’t balance out, but it is still valid. So when...
  20. A

    Touching live wires on high voltage line.

    Hey everyone :) I'm working as an automation engineer and I've always asked myself why people say, that for example birds, can sit on power-lines, because they aren't touching neutral/different potential and no current is flowing. I can't really get this explanation into my head, because...