circuit help

  1. Ayuu90

    Room Noise Detector

    Helloo does anyone know how to explain this circuit in detail, like what each part is meant for or is there any theoretical equations needed?
  2. Ayuu90

    Room Noise Detector Circuit

    Helloo we have trouble replicating this circuit, from what I read before its missing a diode for C4 to discharge its signal, although I'm not sure what kind and where to place it
  3. lukxa

    Dual switch with two outputs and constant third

    Hello everyone, I made 3 fans for resin 3d printer enclosure. 2 of those are main fans to take air out of chamber and third one is inline fan to push air further down the pipes. I have 2 switches and want to wire 2 main fans to those switches so one switch controlls one fan. How can I connect...
  4. Tomarnes

    Help - Is this PCB board burnt?

    Hi Got asked by a friend to try and fix this «speaker» but for me it looks like the circuit is burned. Is that true? I also have no experience in fixing and soldering a pcb board, so should i just throw it away? Thanks for your time!
  5. D

    Does this work? This circuit uses an op-amp and a transistor to detect and cut off the loud noises.

    1: Microphone: The microphone is connected to the non-inverting input of the op-amp, which is pin 3 in this case. 2: Potentiometer: The potentiometer is used to set the threshold level for the loud noises. It is connected to the inverting input of the op-amp, which is pin 2 in this case. The...
  6. R

    Why am I getting an unexpected voltage on the collector of my transistor

    Hi, I am working on a project that requires some hardware design but I am very much an amateur when it comes to circuits (software eng by trade), and I'm getting some results that I can't wrap my head around. Here is the circuit I will be referencing in my question: This circuit worked for...
  7. 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...
  8. 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...
  9. 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...
  10. 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...
  11. 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...
  12. 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...
  13. 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...
  14. 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...
  15. 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?
  16. 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...
  17. 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...
  18. 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...
  19. 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...