circuit help

  1. AverageMoss

    How to detect 24VAC as 5VDC input for microcontroller?

    Hello, I'm working on a little side project for my home thermostat. I recently bought a nest smart thermostat to replace my old "dumb" thermostat and ran into an issue with the wires. I don't have enough wires to accommodate all of the thermostat functions. Running new wiring is not an option...
  2. A

    Need Help for fixing/improving boost converter design

    I'm pretty newbie. i designed a boost converter as hobby and need some help about that. not sure if it will work. how can i fix or improve the circuit. i aimed 5 Vin and 15V 10A max out and use 555 for generate pwm signal for mosfets. But i know 555 can generate max %50 duty cycle and it means i...
  3. M

    Oil well ignition module

    Help! I have an old natural gas engine that I have designed a Capacitor Discharge Ignition module for. The module uses a pre-made boost circuit that takes 12vDC from a truck battery / solar cell and boosts it to 350vDC that I then route to my ignition circuit. This worked great on the bench...
  4. S

    Modelling this circuit

    Hello Leute, I've been having a hard time with my school project and wondered if you could help me. My task is that I have to modell a circuit of wireless charging (seen on the picture). For help I was given this Wikipedia link and later on I was told by my teacher that my main goal should be...
  5. M

    Help! Triac operation for AC motor

    Hello everyone and greetings. I have got my hands on this massage chair that has all it's functions working all right except for the up down mechanism. As soon as it is started the main assembly moves up and hits the upper limit switch but the drive motor does not stop and starts to vibrating...
  6. ShinyFace

    Mini automated solar powered lamp

    Hi everyone, I'm trying to build a solar powered lamp that automatically turns on when it gets dark for my grandfather. He has already purchased a small solar panel connected with micro USB to a light bulb that has to be switched on, but I wanted to automate this by connecting a photo resistive...
  7. K

    Clock edge detector using capacitor and resistor problem

    I have watched recently this video: At the end of it he describe a way to make edge detector by using capacitor and resistor. The thing is i don't see it being discharged in any way. Would't it make it impossible to charge again and in consequence make current flow through the resistor and make...
  8. justaskingonce

    7447 does not show correct numbers on 7 segment dispaly

    Im trying to put a bcd input into a 7 segement display, but as it only shows the numbers 4 to 8 correctly, in all other numbers all of the segments are on, does anyone knows why? you can see the binary input on the right video...
  9. C

    Please help!, What is it designed to do?

    Can anyone tell me what this is??? What is it designed to do? And how new is it perhaps?
  10. E

    I need help with coil gun circuit

    Hello, I have been making circuits as a hobby for 2 years now mainly focusing on trying to make a coil gun, and tried and failed 7 times now, and I am in desperate need of help with the circuit, if you see anything wrong with my diagram please respond as soon as possible. I bought most of the...
  11. 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...
  12. IgnacioMorac

    Crowbar Circuit To protect Sensor for overvoltage

    Hello partners I come to you to help me determine what resistance values or what other components I need to be able to design a crowbar circuit that protects my sensor against overvoltages. My intention is to take care of my sensor for voltages above 40V. So I started to design this crowbar...
  13. M

    Problem integrating a TL072 audio mixer circuit on stripboard

    Hey! So I've been trying to build a modular synth on/off for the last year or so, and one of the most simple projects I thought I should start with is a mixer circuit. I found a really simple circuit schematic and shortly after got it working on breadboard, with absolutely no problem at all...
  14. M

    Help! Identify the IC

    Came across this IC from my car dash. I believe it to be the microprocessor and need help identify it. The IC in question is the one marked IC15 (the biggest one) in the image below. Additional, would appreciate if anyone could guide me as to finding out the logic stores in the IC. Thanks in...
  15. Gralf

    Help! Replacing button on PCB.

    Hello all! New homeowner here, and our house has what I am told to be a pretty nice Gas Fireplace. Which would be great except that the up key on the remote control doesn’t really work. I don’t really want to fork out the $100+ for a new remote (new homeowner and father!!) and I am pretty...
  16. M

    LG Mh6342 control board repair.

    Hay guys, I'm in a grind with this LG microwave control board. It had a gentle but sevier death. Upon inspection found leaked capacitors, two damaged optocouplers , a blown inductor and a pitted IC- LNK 364DN. I changed the caps and inductor. I changed all the parts, although had to jerryrig the...
  17. KaputFPV

    Mosfet array for low voltage and low current

    (I am quite new to electronics and pcb design.) (necessary files are attached, tell me if you need something else ) ------------------------------------------------------------------------------------------------------------------------------------------- Hi everyone, I am making a MOSFET...
  18. Ron2020

    Wiring Headlight and turn signals for a simpleton

    Greetings, My current project is trying to wire a headlight and two turn signals to a motorbike using a 12v rechargeable battery. There are no existing electrical parts of any kind for lighting aside from what I’m doing currently. Complete custom job. I need advice: What I have is: A switch...
  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...
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