circuit design

  1. isagollo

    Human Electrical Current Circuit Touching Hands Transistor NPN

    My project purpose is that when you hold hands with a friend the passage of electric current through a circuit is enough to turn a buzzer or the ISD1820 voice recorder speaker. My first idea it to use the circuit below as reference, but I have no idea which transistor I should use to have...
  2. HDJG

    Power management for 6 axis robotic arm

    Hello Guys, Im currently in the process of designing and then building a robotic arm. And now im designing the electronics for it. They should be pretty simple "i hope". I've attached a picture of the circuit that I am currently designing on, and maybe you notice im not an electrical engineer...
  3. N

    Humidity sensor (HR202L) Help for a uni project.

    Hi there, I am trying to create a circuit to measure humidity in the air. When I try to interpret the values obtained, they do not correspond to the table of values that the manufacturer of the HR202L provides. Could someone explain to me the possible errors in my circuit or my calculations...
  4. UCanDoIt2

    Power Circuit Design - Car powered Apple AirTag

    Overview - I would like to install an Apple AirTag in a vehicle and have it gets its primary power from the vehicle's 12V battery. In the event that the 12V Battery is disconnected, I would like for a backup 3V Battery to continue to provide the power required to run the AirTag. Approach -...
  5. scorpio20

    Can some please create a circuit diagram for this board.

    This is an 8 function led strip light adapter and i want yhe circuit diagram of it can some one please help me out.
  6. Adi999xx

    Need Suggestions for my project

    I have an adjustable power supply of 150W.I want to power two peltier modules of 12v/6amps and 12v/3amps and two fans each of 12v/0.72amps. Please suggest me an efficient way to power all devices.
  7. M

    Troubleshooting Differential Signal Issues with DS26LV32

    Hello, I wanted to reach out to this wonderful community to seek some guidance regarding an issue I'm facing with the DS26LV32 and DS26LV31 ICs on my board. I believe your collective expertise and experience can help shed some light on this problem. In my current project, I am utilizing the...
  8. Aadek

    Battery pack help

    Hi I'm having some issues designing a circuit for a project I'm working on. It's a 48v Ebike battery but im including USB C charging so i can charge my phone on the go and i was thinking of including the option of charging the battery pack via USB C in case i dont have the normal charger for...
  9. Topad

    Zener Diode voltage regulation

    Hi All, I have two designs using a zener diode for volatge regulation at 24V supply volatge. I like to know which is a better design to go with. Please see attach image. The load device is an active buzzer, that uses 15ma at 4v. Design #1: I have a shunt zener regulator using a resitor that...
  10. S

    SI5389 Clock Synthesizer reference schematics

    Hi all, I'm trying to implement a IEEE1588 Network Synchronizer using SI5389 Clock Synthesizer from Silicon/Skyworks. However, I'm not able to find a reference design for the above and need schematic designs. Would be of great help if you share a design if any to get an understanding of how I...
  11. A

    Driving RFP30N06LE N-Channel MOSFET with TC4420 MOSFET Driver

    Hi all, I'm trying to drive a RFP30N06LE N-Channel MOSFET with TC4420 MOSFET Driver. The MOSFET is used to switch a [1W LED][1]. The input to the MOSFET driver is provided by the 5V from an Arduino Nano. But my circuit is not working: it seems that the VDD somehow leaks to the input of the...
  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

    Asynchronous counter that counts from 0 to 13

    Hello everyone. I'm having troubles with my homework. This is the description: The aim of the assignment is to design an asynchronous counter that counts from 0 to 13. Design assumptions: The counters should be asynchronous and implemented with flip-flops and logic circuit gates. • The...
  14. spacejedigundam

    how to Vernier TDC adjust every stage time differential to achieve 1 TLSB ?

    How do we get td1 - td2 = 2ns? I have no IDEA about how to adjust delay cell ,Thanks solving my problem , Thanks a lots
  15. B

    Help with LM3914 Tachometer w/ shift light

    Hello, I'm currently working on an LED bar tachometer using an LM3914, with the alarm flasher functionality being used as a shift light. I followed a circuit diagram from this post ( about setting the input to be 0-5v...
  16. pidgin

    Circuit review/analysis for a stepper motor auto-enabling and time-delay mechanism.

    Hi people :) I would love some help reviewing my little circuit.. I have a stepper motor driver (TB6600) which has an "ENABLE" function. It has an ENA- that is supposed to be connected to the ground, and a ENA+ where you supply the signal for ENABLING or DISABLING the stepper motor connected...
  17. C

    Active filtering circuit design

    Hello everyone, I need to design a circuit on breadboard that give filtered outputs as "0.5-4 Hz; 4-7 Hz; 7-12 Hz; 12-30 Hz; 30-100 Hz; 100-1000 Hz" using active filter principles with introducing input signal. Can anyone help me? Thanks in advance.
  18. E

    Trying to design an audio circuit with a carbon single button microphone so that I can output the audio into a PC

    So I recently purchased a 285W western electric transmitter as I'm trying to more or less make a microphone that can plug into a computer which uses a carbon button microphone from the early 20th century. I have little education in circuit design, though I know enough to know I probably made...
  19. D

    Up/Down Counter with 2 input sensors to trigger clock

    Hello, can you help me with this project? I want to design a circuit which counts up when the ENTRANCE SENSOR detects an object and counts down when the EXIT SENSOR detects an object. I created the circuit design attached below with the help of some tutorials on YouTube but I do not know what...
  20. I

    T.I. BLE USB MCU Programming Trouble (CC2540)

    Hello Everybody! I am trying to program/communicate with the CC2450 BLE IC, which is a transceiver/microcontroller. My computer is having trouble recognizing the device. It does not show up in Device Manager. I've tried the T.I. tools for trying to communicate with it. I've downloaded the BLE...